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Introduction: High‐frequency low‐tidal‐volume (HFLTV) ventilation during radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) has been shown to be superior to standard ventilation (SV) in terms of procedural efficiency, acute and long‐term clinical outcomes. Our study aimed to compare ablation lesions characteristics utilizing HFLTV ventilation versus SV during RFCA of PAF. Methods: A retrospective analysis was conducted on patients who underwent pulmonary vein isolation (PVI) for PAF between August 2022 and March 2023, using high‐power short‐duration ablation. Thirty‐five patients underwent RFCA with HFLTV ventilation and were matched with another cohort of 35 patients who underwent RFCA with SV. Parameters including ablation duration, contact force (CF), impedance drop, and ablation index were extracted from the CARTONET database for each ablation lesion. Results: A total of 70 patients were included (HFLTV = 35/2484 lesions, SV = 35/2830 lesions) in the analysis. There were no differences in baseline characteristics between the groups. While targeting the same ablation index, the HFLTV ventilation group demonstrated shorter average ablation duration per lesion (12.3 ± 5.0 vs. 15.4 ± 8.4 s, p <.001), higher average CF (17.0 ± 8.5 vs. 10.5 ± 4.6 g, p <.001), and greater impedance reduction (9.5 ± 4.6 vs. 7.7 ± 4.1 ohms, p <.001). HFLTV ventilation group also demonstrated shorter total procedural time (61.3 ± 25.5 vs. 90.8 ± 22.8 min, p <.001), ablation time (40.5 ± 18.6 vs. 65.8 ± 22.5 min, p <.001), and RF time (15.3 ± 4.8 vs. 22.9 ± 9.7 min, p <.001). Conclusion: HFLTV ventilation during PVI for PAF was associated with improved ablation lesion parameters and procedural efficiency compared to SV. [ABSTRACT FROM AUTHOR]

Background: High-power short-duration (HPSD) ablation creates wide, shallow lesions using radiofrequency (RF) heating. It is uncertain if adjusting RF energy based on atrial wall thickness provides extra benefits. We studied the safety and effectiveness of tailored HPSD energy based on left atrial (LA) wall thickness (LAWT) for circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF). Methods: We enrolled 212 patients (68.4% male, mean age: 59.5 ± 11.0 years) and randomly assigned them to two groups: LAWT-guided CPVI (WT, n = 108) and conventional CPVI (control, n = 104). Both groups used an open irrigated-tip deflectable catheter to apply 50 W for 10 s to the posterior LA, while controls used 60 W for 15 s on other LA regions. RF delivery time in WT was titrated (15 s at LAWT > 2.1 mm, 13 s at 1.4-2.1 mm, and 11 s at <1.4 mm) according to the computed tomogram-myocardial thickness color map. Results: After a mean follow-up of 13.4 ± 7.0 months, the WT and control groups showed no significant difference regarding clinical recurrence rate (13.9% vs. 5.8%, respectively; p = .061) and major complication rate (4.6% vs. 3.8%, respectively; p > .999). The total procedure time, cardioversion rate, and post-procedural AAD prescription rates did not significantly differ between the groups. Conclusions: The LAWT-guided energy titration strategy did not result in improved procedural safety and efficacy compared to the conventional 50--60 W-HPSD CPVI in patients with PAF. [ABSTRACT FROM AUTHOR]

Introduction: The optimized ablation index (AI) value for catheter ablation of atrial fibrillation (AF) remains to be defined. We aimed to compare the efficacy and safety of CLOSE protocol and lower AI protocol in paroxysmal AF. Methods and Results: Patients with symptomatic, drug‐resistant paroxysmal AF for first ablation were prospectively enrolled from September 2020 to January 2022. The patients were randomly divided into CLOSE group (AI ≥ 550 for anterior/roof segments and ≥400 for posterior/inferior segments) and lower AI group (AI ≥ 450 for anterior/roof segments and ≥350 for posterior/inferior segments). First‐pass isolation, acute pulmonary vein (PV) reconnections, 1‐year arrhythmia recurrence, and major complications were assessed. Of the 270 enrolled patients, 238 completed 1‐year follow‐up (118 in CLOSE group and 120 in lower AI group). First‐pass isolation in left PVs was higher in CLOSE group (71.2% vs. 53.3%, p =.005). Acute PV reconnections were comparable between groups (9.3% vs. 14.2%, p =.246). At 1 year, 86.4% in CLOSE group versus 81.7% in lower AI group were free from atrial arrhythmia (log rank p =.334). The proportion difference was −4.8% (95% CI: −14.1% to 4.6%), and p =.475 for noninferiority. Stroke occurred in four patients of lower AI group, and no cardiac tamponade, atrioesophageal fistula, major bleeding or death occurred post procedure. Conclusion: For patients with paroxysmal AF and treated by AI‐guided PV ablation, lower AI is not noninferior to CLOSE protocol. [ABSTRACT FROM AUTHOR]

Background: Long‐time monitoring of electrocardiogram with an implantable loop recorder is useful for detection of paroxysmal atrial fibrillation (PAF) in ESUS patients. However, usefulness of noninvasive 7‐day Holter monitoring has not been established. Furthermore, the incidence of other arrhythmias such as sinus pause (SP) remains unknown. Aim: (1) The aim of this study was to examine the usefulness of 7‐day Holter monitoring to detect PAF in both acute and chronic periods since index stroke and (2) to clarify the incidence of SP in ESUS patients. Methods: Prospectively, a total of 738 patients including 241 consecutive ESUS patients were enrolled, from April 2016 to March 2021. One hundred forty patients among 241 consecutive ESUS patients underwent chest strap‐style 7‐day Holter monitor. We examined PAF and SP (≧3 s). Results: The 7‐day Holter monitoring started since index stroke at a median of 17 days. Among 80 patients within 1 month since index stroke, PAF was detected in three patients (3.8%) and SP was in two patients (2.5%). By contrast, among 52 patients over 1 month since index stroke, PAF was found in only one patients (1.9%). Conclusion: Although the incidence of PAF detected with this monitoring was low (3.8%) in ESUS patients, SP was also found in 2.5% within 1 month since index stroke. Within 1 month since stroke onset in ESUS patients, 7‐day Holter monitoring would be useful for detection of PAF and SP that would be potentially a cardiac source of embolism and might require urgent intervention. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary vein isolation (PVI) is well established as a primary treatment for atrial fibrillation (AF). The POLAR ICE study was designed to collect prospective real world data on the safety and effectiveness of the POLARxTM cryoballoon for PVI to treat paroxysmal AF. Methods: POLAR ICE, a prospective, non‐randomized, multicenter (international) registry (NCT04250714), enrolled 399 patients across 19 European centers. Procedural characteristics, such as time to isolation, cryoablations per pulmonary vein (PV), balloon nadir temperature, and occlusion grade were recorded. PVI was confirmed with entrance block testing. Results: Data on 372 de novo PVI procedures (n = 2190 ablations) were collected. Complete PVI was achieved in 96.8% of PVs. Procedure and fluoroscopy times were 68.2 ± 24.6 and 15.6 ± 9.6 min, respectively. Left atrial dwell time was 46.6 ± 18.3 min. Grade 3 or 4 occlusion was achieved in 98.2% of PVs reported and 71.2% of PVs isolation required only a single cryoablation. Of 2190 cryoapplications, 83% had a duration of at least 120 s; nadir temperature of these ablations averaged −56.3 ± 6.5°C. There were 6 phrenic nerve palsy events, 2 of which resolved within 3 months of the procedure. Conclusion: This real‐world usage data on a novel cryoballoon suggests this device is effective, safe, and relatively fast in centers with cryoballoon experience. These data are comparable to prior POLARx reports and in keeping with reported data on other cryoballoons. Future studies should examine the long‐term outcomes and the relationship between biophysical parameters and outcomes for this novel cryoballoon. [ABSTRACT FROM AUTHOR]

Introduction: Catheter ablation for atrial fibrillation (AF) is a common therapeutic strategy for patients with either paroxysmal AF (PAF) or persistent AF (persAF), but long‐term ablation success rates are imperfect. Maintenance of sinus rhythm immediately before ablation with antiarrhythmic drug (AAD) therapy has been associated with improved outcomes in patients undergoing ablation. Amiodarone has superior efficacy relative to other AADs. Whether failure of amiodarone to maintain sinus rhythm before ablation for either PAF or persAF is associated with poor outcomes is unknown. Methods: A total of 307 patients who received amiodarone in a 1‐year window before undergoing catheter ablation for AF were included. Patients were divided into amiodarone success (n = 183) and amiodarone failure (n = 124) groups based on the response to pre‐ablation amiodarone treatment. Analysis of procedural outcomes as a function of response to amiodarone therapy was performed. Patients were followed for at least 12 months postablation, to assess outcomes (adverse events and arrhythmia recurrence). Procedural success was defined by the absence of documented arrhythmia (>30 s) without any antiarrhythmic agents beyond a 90‐day blanking period. Results: Following ablation for either PAF or persAF, freedom from any recurrent atrial arrhythmia at 1 year was 57.7% for the entire cohort. One‐year freedom from recurrent arrhythmia in the amiodarone success group was comparable to that in the amiodarone failure group (55.7% vs. 60.5%; p =.54). Success rates following ablation did not vary by the response to amiodarone when analyzed for PAF or persAF subgroups. Conclusion: Failure to restore and maintain sinus rhythm with amiodarone before ablation for either PAF or persAF is not a predictor of ablation procedural failure. Amiodarone failure alone should not deter practitioners from considering ablation therapy for patients with AF. [ABSTRACT FROM AUTHOR]

Background: The outcome of catheter ablation could probably differ among patients with atrial fibrillation (AF), depending on age and AF type. We aimed to investigate the difference in predictors of outcome after catheter ablation for AF among the patient categories divided by age and AF type. Methods and Results: A total of 396 patients with AF (mean age 65.69 ± 11.05 years, 111 women [28.0%]) who underwent catheter ablation from January 2018 to December 2019 were retrospectively analyzed. We divided the patients into four categories: patients with paroxysmal AF (PAF) or persistent AF (PeAF) who were 75 years or younger (≤75 years) or older than 75 years (>75 years). Kaplan–Meier survival analysis demonstrated that patients with PAF aged ≤75 years had the lowest AF recurrence among the four groups (log‐rank test, p =.0103). In the patients with PAF aged ≤75 years (N = 186, 46.7%), significant factors associated with recurrence were female sex (p =.008) and diabetes (p =.042). In the patients with PeAF aged ≤75 years (N = 142, 35.9%), the only significant factor associated with no recurrence was medication with a renin‐angiotensin system inhibitor (p =.044). In the patients with PAF aged >75 years (N = 53, 14.4%), diabetes was significantly associated with AF recurrence (p =.021). No significant parameters were found in the patients with PeAF aged >75 years (N = 15, 4.1%). Conclusions: Our findings indicate that the risk factors for AF recurrence after catheter ablation differed by age and AF type. [ABSTRACT FROM AUTHOR]

Background: Cryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow‐up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients. Hypothesis: To evaluate the clinical efficacy of high‐mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1‐year follow‐up. Methods: We included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year. Results: A total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p =.03). However, no differences were noted in the levels of other biomarkers such as preoperative high‐sensitivity C‐reactive protein (hs‐CRP), postoperativehs‐CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17–23.92], p =.04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1‐year AF‐free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49–9.75], p =.005). Conclusion: In pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence. [ABSTRACT FROM AUTHOR]

Background: It has been observed that the fourth‐generation cryoballoon (CB4) ablation catheter increased the rate of acute real‐time recordings of pulmonary vein isolation (PVI) during the ablation for the treatment of atrial fibrillation (AF). The aim of this analysis was to compare the long‐term outcome results between patients treated with the CB4 and second‐generation cryoballoon (CB2). Methods: In total, 492 patients suffering from AF, underwent PVI ablation with either the CB2 or CB4 catheter within this examination of the 1STOP real‐world Italian project and were included in the analysis. Specifically, 246 consecutive patients treated by CB4 were compared to 246 propensity‐matched control patients who underwent PVI using CB2. Results: When comparing the patient cohorts treated with CB2 versus CB4, acute success rate (99.6 ± 4.7% vs. 99.7 ± 3.6%, p =.949) and peri‐procedural complications (3.7% vs.1.2%, p =.080) were similar in both groups, respectively. However, procedure time (100 vs.75 min, p <.001) and fluoroscopy duration (21 vs.17 min, p <.001) were all significantly lower in the CB4 treated patient cohort. At the 12‐month follow‐up, the freedom from AF recurrence after a 90‐day blanking period was significant higher in the CB4 as compared with the CB2 group (93.3% vs.81.3%, p <.001). Conclusions: In summary, usage of the CB4 ablation catheter increased the rate of acute PVI recording capability and resulted in a higher rate of long‐term PVI success, as demonstrated by the reduced rate of AF recurrence in comparison to the CB2 cohort at the 12‐month follow‐up period. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the application value of different‐duration electrocardiograms (ECGs) in paroxysmal atrial fibrillation (AF) diagnosis. Methods: A total of 220 patients with paroxysmal atrial fibrillation diagnosed by 24‐h dynamic electrocardiogram in our hospital from January 2019 to December 2020 were selected as the study subjects. The patients were monitored for 10 s, 5 min, and 24 hr, respectively. The results of the three different‐duration ECGs were compared and analyzed in order to evaluate their paroxysmal AF diagnosis value. Results: Paroxysmal AF was detected in 18 patients (8.2%) with the 10‐s ECG; in 89 patients (40.5%) with the 5‐min ECG; and in 199 patients (90.5%) with the 24‐h dynamic ECG. Conclusion: In patients with paroxysmal AF, ECGs with longer detection times had higher detection rates. [ABSTRACT FROM AUTHOR]

Background: The adiponectin‐to‐leptin (A/L) ratio has been identified as a potential surrogate biomarker for metabolic disorders. However, it remains unknown whether the serum A/L ratio is associated with heart rate variability in paroxysmal atrial fibrillation (AF). Methods: For this retrospective study, we included consecutive patients who underwent 24‐h long‐range electrocardiogram examination in our center for paroxysmal AF. The results of echocardiography, heart rate variability tests, and blood tests were also retrieved. Multivariate line regression analysis was performed to evaluate identify factors independently associated with heart rate variability. Results: Among the 85 included patients with paroxysmal AF, the median A/L ratio was 1.71. Univariate analysis indicated that patients with a low A/L ratio (<1.71, n = 42) had a lower high‐frequency (HF) power and a higher hs‐CRP level, low‐frequency (LF) power, and LF/HF ratio than those with a high A/L ratio (≥1.71, n = 43). Multivariate linear regression analysis showed that the serum leptin concentration was independently and positively associated with LF (β = 0.175, p =.028), while the serum adiponectin concentration was independently and positively associated with HF (β = 0.321, p =.001). Moreover, the A/L ratio was independently and negatively associated with the LF/HF ratio (β = −0.276, p =.007). Conclusions: The A/L ratio was independently and negatively associated with the LF/HF ratio in patients with new‐onset paroxysmal AF. [ABSTRACT FROM AUTHOR]

Background: Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy. Objective: To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF. Methods: MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random‐effects Bayesian network meta‐analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI). Results: Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10–0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16–1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06–1.96) nor RFA (OR: 0.34; 95% CrI: 0.07–1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13–0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44–1.39) nor RFA (OR: 1.45; 95% CrI: 0.67–3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01–0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44–1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events. Conclusion: Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences. Atrial fibrillation (AF) has been associated with significant morbidity and mortality. Early treatment of AF can decrease recurrences or arrhythmia burden; avoiding, as such, functional and economically debilitating consequences. In this network meta‐analysis, the safety and efficacy of cryoablation, radiofrequency ablation (RFA), and antiarrhythmic drugs (AAD) as initial treatments of paroxysmal AF were compared. The study shows that cryoablation and RFA, employed as the first‐line strategy for the treatment of AF, significantly reduce atrial tachyarrhythmia recurrences compared to AAD without increasing the risk of serious adverse events. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein (PV) isolation is an established treatment for paroxysmal drug‐refractory atrial fibrillation (AF). High parasympathetic tone and reconnection of PVs have demonstrated to be possible culprits of AF recurrence after ablation. Our aim was to investigate the association between parasympathetic tone and reconnected PVs in patients with paroxysmal AF. Methods: Consecutive patients who underwent a redo catheter ablation procedure for atrial tachyarrhythmia recurrence by means of 3D electroanatomic mapping with documentation of presence or absence of PVs reconnection following an initial procedure of cryoballoon (CB) ablation for symptomatic drug‐refractory paroxysmal AF were screened for the study. Results: A total of 92 patients were included, of whom 50 (54.35%) were males. Reconnected PVs were found in 64 (69%) patients. PVs reconnection could be predicted by DC (C‐statistic =.770), by SDNNI (C‐statistic =.714) and by absolute VLF power (C‐statistic =.722), while right‐sided PVs reconnection could be better predicted by DC (C‐statistic =.848) and by SDNNI (C‐statistic =.761). In multivariate binary logistic regression analysis, a DC value ≥6.45 ms and an absolute VLF power value ≥160 ms2 were associated with three times and five times higher odds of PVs reconnection, respectively. On a vein‐per‐vein analysis, absolute VLF power ≥160 ms2 was associated with three times higher odds, while reaching of −40°C within 60 s was associated with three times lower odds of PVs reconnection. Conclusion: High parasympathetic tonus accurately predicts PVs reconnection. On a vein‐per‐vein analysis, parasympathetic markers along with biophysical parameters predicted PVs reconnection. On a case‐by‐case analysis, parasympathetic markers were the only predictors of PVs reconnection, thus being a robust PVs reconnection prediction tool. [ABSTRACT FROM AUTHOR]

Background: Recent randomized controlled trials (RCTs) suggest that ablation is superior to antiarrhythmic drugs (AADs) as an initial therapy for paroxysmal atrial fibrillation (pAF) to prevent arrhythmia recurrences. We performed an updated meta‐analysis of RCTs, to include recent data from cryoballoon‐based ablation and to compare arrhythmia‐free survival and adverse events between ablation and AADs. Methods: We searched MEDLINE and EMBASE from inception to December 2020. We included RCT comparing patients with pAF undergoing ablation or receiving AADs as an initial therapy. We combined data using the random‐effects model to calculate hazards ratio (HR) for arrhythmia‐free survival and odds ratio (OR) for adverse events. Results: Five studies from 2005 to 2020 involving 985 patients were included (495 patients and 490 patients underwent ablation and medication as initial therapy, respectively). Patients who underwent ablation had higher freedom from atrial tachyarrhythmias (ATs) during the 12‐24 months follow‐up period (pooled HR = 0.48, 95% CI: 0.40‐0.59, P <.001). In a subgroup analysis of ablation method used, both cryoablation group (pooled HR = 0.49, 95% CI: 0.38‐0.64, P <.001) and radiofrequency ablation group (pooled HR = 0.47, 95%CI: 0.35‐0.64, P <.001) showed reduction in AT recurrence compared with AAD group. There were no differences in adverse events including cerebrovascular accident, pericardial effusion or tamponade, pulmonary vein stenosis, acute coronary syndrome, deep vein thrombosis and pulmonary embolism, and bradycardia requiring a pacemaker. Conclusion: Catheter ablation (both cryoablation and radiofrequency ablation) is superior to AAD as an initial therapy for pAF in efficacy for reducing AT recurrences without a compromise in adverse events. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is a highly prevalent arrhythmia, with substantial associated morbidity and mortality. Circumferential pulmonary vein ablation (CPVA) is an effective rhythm control strategy, however, recurrence is an important factor influencing treatment decisions. Hypothesis: To develop a predictive model based on left atrial (LA) structure and function, and evaluate its efficiency in predicting the recurrence of AF after CPVA. Methods: Patients with paroxysmal AF who underwent CPVA were enrolled in this study and randomly divided into a development set and a validation set. The clinical and echocardiographic data of each patient were collected. In the development set, a least absolute shrinkage and selection operator (LASSO) regression was used to establish a LA ultrasound feature. By combining that LA ultrasound feature with independent clinical risk factors, we established an echocardiographic model using multivariate logistic regression and plotted the corresponding nomogram. Results: The LA ultrasound feature established by LASSO regression included nine echocardiographic indicators related to LA structure and function. It also exhibited good predictive ability in both the development set and the validation set (AUC:0.944, 95%CI: 0.910–0.978; AUC:0.878, 95%CI: 0.816–0.942). Logistic regression analysis indicated that LA ultrasound feature and AF duration were independent predictors for AF recurrence. The combined model including LA ultrasound feature and AF duration also showed good discriminability in both the development set (AUC: 0.950, 95% CI:0.914–0.985) and the validation set (AUC: 0.890, 95% CI: 0.831–0.949). The calibration curve showed good agreement between the predicted value and observed value. Conclusions: Our model that is based on LA structure and function measured by echocardiography is a useful non‐invasive preoperative tool, which exhibits good accuracy in predicting the recurrence of AF after CPVA. [ABSTRACT FROM AUTHOR]

Background: Limited information is available on paroxysmal atrial fibrillation (PAF) in the horse. Indeed, undiagnosed PAF could result in poor performance. Due to the intermittent occurrence, PAF is difficult to diagnose. However, implanting a small ECG device (implantable loop recorder, ILR) subcutaneously, allows the continuous and automatic detection of PAF. Objectives: The aim was to investigate the potential of ILRs as a tool for diagnosing PAF in horses with poor performance. Study design: Prospective field study. Methods: Twelve racing Standardbred trotters with intermittent reduced performance (mean age: six years) were enrolled prospectively. The ILR was implanted subcutaneously at the fifth or sixth left intercostal space and data from the ILR was collected during the study period in which the horses were followed for a median duration of 7.5 month (range 6‐28). Results: The ILR was able to detect PAF in four out of twelve racehorses. The ILR also detected sustained atrial fibrillation (AF) in one horse during the study. The ILRs rely on RR detection and R waves were correctly identified in 96%. One hundred episodes were categorised as AF by the ILRs and subsequently visual ECG inspection categorised 12 as sinus rhythm (SR), 28 as sinus arrhythmia (SA), 14 as other arrhythmias and 46 as AF episodes. The Root Mean Square of the Successive Differences (RMSSD) values were significantly increased for AF compared to SR and SA. Main limitations: Few horses included and duration of study period varied among the horses. Further it was not possible to assess the sensitivity of the device in the current study and the ILRs proved to have a high rate of false positive misclassifications. Conclusions: This study indicates that ILRs can be used for detection of PAF episodes and could be a useful ECG tool for horses presenting with poor performance. This methodology provides a platform to facilitate the long‐term assessment of AF development and quantification of AF burden in horses. Further studies including both healthy and poor performing horses are needed in order to learn more about PAF prevalence in racehorses. [ABSTRACT FROM AUTHOR]

Introduction: Ablation index (AI)‐guided radiofrequency ablation has been increasingly used for the treatment of drug‐resistant paroxysmal atrial fibrillation (AF)，but the optimal AI targets remain to be determined. We aimed to examine the efficacy and safety of catheter ablation guided by moderate AI values but more strict procedural endpoints in patients with paroxysmal AF. Methods: We conducted a retrospective review of a consecutive series of patients who received their first AI‐guided ablation for paroxysmal AF from 2017 to 2018. The standard procedural protocol recommends AI targets as follows: anterior: 400–450; posterior: 280–330; and roof/inferior wall: 380–430. After circumferential pulmonary vein isolation (PVI), we performed bipolar pacing along the ablation line, adenosine triphosphate (ATP)‐provocation, and waited for 30 min to verify PVI. The primary clinical outcome was the rate of freedom from AF recurrence at 12 months. Results: A total of 140 consecutive patients were included. The mean procedure and ablation times were 132.2 ± 30.2 min and 24.2 ± 7.9 min, respectively. The first‐pass isolation and final isolation rates were documented in 49.3% and in 100% of the patients, respectively. At 12 months, single‐procedure freedom from atrial tachyarrhythmias was observed in 92.1% of patients. No major procedure‐related complications were encountered. Conclusions: Moderate AI‐guided catheter ablation is highly effective for the treatment of drug‐refractory paroxysmal AF in real‐world settings. Over 90% of patients achieved single‐procedure arrhythmia‐free survival at 1 year. The outcome was obtained without major complications and the procedure involved relatively short procedure and ablation times. [ABSTRACT FROM AUTHOR]

Introduction: Contact force (CF) guided ablation of paroxysmal atrial fibrillation (PAF) with stable catheter‐tissue contact optimizes clinical success and may increase an operator's ability to achieve pulmonary vein isolation (PVI) in a single encirclement. First pass PVI reduces procedure time but the relationship with long term clinical success is not well understood. This study evaluated patient characteristics and procedural details as predictors of 1‐year clinical success after PAF ablation, including first pass isolation. Methods: Consecutive de novo PAF ablations were performed with a porous tip CF catheter in 2017 and 2018. All ablations used wide‐area circumferential ablation, with first pass isolation captured separately for the left and right pulmonary veins (PVs). CF was held between 10 and 20 g and the catheter was moved every 10–20 s. Radiofrequency energy was set at 40–45 W throughout the atrium. Patient characteristics and procedural details were tested for association with clinical success, defined as freedom from recurrent atrial tachyarrhythmia through 1 year. Results: A total of 404 patients were included in the study. Clinical success at 1 year was 86.6%. Achieving first pass isolation on at least one ipsilateral PV pair was the most significant predictor of clinical success (p =.0126). After controlling for first pass isolation, only recurrence within the 90‐day blanking period was independently predictive (p =.0015). First pass isolation was not associated with early recurrence (p =.2454). Conclusion: In a real‐world setting, first pass isolation was highly predictive of 12‐month clinical success after CF‐guided ablation in a PAF population. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation has emerged as a major strategy for paroxysmal atrial fibrillation (PAF). Atrial electrical remodeling (AER) plays a critical role in the recurrence of PAF after ablation. Hypothesis: To characterize the immediate trends of AER during ablations in patients with PAF, and assess the relationship between immediate trends and recurrence. Methods: We performed this prospective observational study of 135 patients to investigate AER following three ablation modes: radiofrequency ablation (RFA), cryoablation (CA) and 3D mapping‐guided cryoablation (3D‐CA). The atrial effective refractory period (AERP) and atrial conduction time (ACT) were measured via electrophysiology before and immediately after ablation, and P‐wave indices were measured via electrocardiography before and within 24 h after ablation. Follow‐up visits were conducted for at least 1 year or until relapse. Results: Different approaches of ablation caused a fairly significant increase in the shortest P‐wave duration and AERP in both the proximal coronary sinus (PCS) and distal coronary sinus (DCS) but caused a shortened P‐wave dispersion. No different effect was found at the AERP among the three modes. Compared to patients who received CA, among patients who received RFA, a significant reduction in total ACT and right ACT was seen. Statistically, there was a weakly positive association between changes in total ACT and early recurrence. Conclusions: Injury during ablation for PAF was associated with an increase in the AERP but not in the ACT. Total ACT and right ACT were shorter after RFA than after CA. The increase in total ACT were slightly predictive of early recurrence. [ABSTRACT FROM AUTHOR]

Background: The success rate after cryoballoon ablation (CB‐A) performed for paroxysmal atrial fibrillation (PAF) might be overestimated by traditional noninvasive monitoring techniques. The purpose of this study was to evaluate the mid‐term outcome of CB‐A in patients with PAF implanted with an implantable loop recorder (ILR) after the procedure. Methods: Between January 2017 and March 2019, all patients who underwent CB‐A for PAF and who were subsequently implanted with an ILR were retrospectively included. All devices were equipped with remote monitoring. All ILR‐documented atrial tachycardia (AT) or AF episodes ≥ 6 min were considered as recurrence; both true and false episodes were collected. A 3‐month post‐procedural blanking period (BP) was applied. Results: A total of 102 patients (77 men, mean age 60.6 ± 9.6 years) who underwent pulmonary vein isolation (PVI) by CB‐A were included; mean time from first diagnosis of AF to PVI was 51.5 ± 46.9 months. Mean follow‐up was 29.3 ± 8.1 months; at 12‐month follow‐up, the success rate was 65.7%, while at 2‐year follow‐up, freedom from AT/AF recurrences was achieved in 59.3% of the patients. In the follow‐up, a total of 4987 ECG strips were analyzed; true‐positive episodes were confirmed in 2026 cases (40.6%), whereas 2961 episodes (59.4%) were considered false‐positive. Conclusion: In patients with PAF implanted with an ILR, CB‐A results in freedom from any AT/AF recurrence in 65.7% of patients at 12‐month follow‐up and in 59.3% of patients when evaluated at 2‐year. Careful adjudication of all ILR‐documented AF episodes is required to avoid misdiagnosis. [ABSTRACT FROM AUTHOR]

Introduction: Given that few studies investigated the efficacy of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (AF) and atrial septal defect (ASD), this study evaluated its effectiveness in patients with paroxysmal AF and ASD. Methods and Results: Of the 216 patients who underwent ASD device closure at two hospitals, 36 patients had paroxysmal AF. After April 2012, CA for AF was performed before ASD device closure (ASD‐CA group; n = 20). The ASD‐CA group had a significantly higher AF‐free survival rate after ASD device closure compared to patients without CA for AF before ASD device closure (ASD‐non‐CA group; n = 16) (ASD‐CA group: 2 patients vs. ASD‐non‐CA group: 9 patients; follow‐up period: 4.2 ± 2.5 years; log‐rank p =.01). In addition, the AF‐free survival rates were similar between the ASD‐CA group and 80 paroxysmal AF patients who underwent CA without any detectable structural heart disease (non‐SHD‐CA group). The two groups were matched by propensity scores for age, sex, and left atrium dimension (ASD‐CA group: 2 patients vs. non‐SHD‐CA group: 5 patients; follow‐up period: 3.3 ± 1.8 years; log‐rank p =.28). Conclusion: CA for AF before ASD device closure might be an effective treatment option for patients with paroxysmal AF and ASD. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) is known to be the most common arrhythmia, and the successful rate of long‐term ablation can vary comparatively. Therefore, a clinical scoring system to predict rhythm outcome remains a critical unmet need. The electrocardiographic (ECG) risk score which is named Morphology‐Voltage‐P‐wave duration (MVP) score was reported to be useful for predicting new‐onset AF. The goal of the current study was to investigate whether the MVP score was a useful scheme in the prediction of rhythm outcome following pulmonary vein isolation (PVI) in paroxysmal atrial fibrillation (PAF). Methods: We retrospectively analyzed baseline characteristics, risk scores, and rates of AF recurrence 12 months postablation in the medical records of 207 consecutive patients with PAF undergoing PVI in General Hospital of Ningxia medical University from 2010 to 2018. Results: Two hundred and seven patients (71 females, median age 58.7 years) with symptomatic PAF underwent PVI. From the cohort, 32.3% (67) had a recurrence of AF within 1 year of the PVI. The area of the MVP score under the curve in the receiver operating characteristics (ROC) analysis was 0.789 (95% CI 0.730–0.840, p <.001). A score cut‐off value of >3 showed the best predictive ability for AF recurrence within 1 year after PVI, with sensitivity (53.03%) and specificity (89.87%). Conclusions: The results of our study suggest that the easy‐to‐measure ECG MVP score can be used to predict recurrence of PAF after PVI. [ABSTRACT FROM AUTHOR]

Introduction: Screening of coexistent typical atrial flutter (AFL) in patients with atrial fibrillation (AF) is sometimes challenging. This study investigated whether a prolonged right atrial conduction time (RACT) estimated by tissue Doppler imaging (TDI) predicts patients with concomitant AFL and AF. Methods and Results: We retrospectively analyzed 398 patients (mean age: 61.6 years, 73.4% men) undergoing catheter ablation of paroxysmal AF. The patients were classified into two groups according to whether they had evidence of AFL (N = 122, 30.7%) determined by a clinical observation (N = 68), induction during procedures (N = 33), or AFL recurrence after procedures (N = 21) or not (N = 276, 69.3%). The preoperative RACT, defined as a longer duration between the onset of the P‐wave and peak A′‐wave on the right atrial lateral wall or septal wall, and total atrial conduction time (TACT), defined as the same time duration on the left atrial lateral wall, were evaluated in all patients. Patients with evidence of AFL had a significantly longer RACT than those without AFL (p <.001). A multiple logistic regression and receiver operator characteristics curve analysis revealed the ratio of the RACT and TACT (RACT/TACT) was the independent and most superior accurate cofounder for predicting evidence of AFL (area under the curve: 0.867). When adding a discriminator of an RACT/TACT ≧ 93% into the conventional screening, 98.4% of the patients with evidence of AFL were estimated to be treated during the initial procedures. Conclusion: The estimated RACT/TACT using the TDI may be useful for predicting patients with concomitant AFL in patients with AF. [ABSTRACT FROM AUTHOR]

Background: The autonomic activity plays a critical role in generating paroxysmal atrial fibrillation (PAF). This study aimed to evaluate the changes in the autonomic nerve activity before and after PAF events in patients with and without ischemic heart disease (IHD).Methods: The study included 49 patients (71.43 ± 12.24 years old, 26 males) with PAF events lasting more than 30 s during 24-hr ambulatory Holter monitoring. The 20-min intervals before and after PAF events were divided into eight segments of 5 min each. Heart rate variability (HRV) analyses of the time and frequency domains were applied to each time segment.Results: Patients with IHD had significant increases in the root mean square successive differences (r-MSSD, p = .008) and HF component (p = .04), followed by a significant increase in the LF/HF ratio (p = .02) preceding the onset of PAF. Patients without IHD had only a significant increase in the r-MSSD (p = .045) preceding the onset of PAF. During the termination of PAF events, patients in both the IHD and control groups had a significantly decreased r-MSSD and HF, respectively.Conclusion: Ischemic heart disease causes a sympathovagal imbalance in the initiation of PAF. Decreased parasympathetic activity regulated the termination of PAF in both the IHD and control groups. The modification of the autonomic nervous system (ANS) activity should be individualized due to the autonomic complexity in AF arrhythmogenesis and termination. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to compare touch‐up ablation (TUA) rates and pulmonary vein isolation (PVI) durability of hot balloon ablation (HBA) and cryoballoon ablation (CBA) in paroxysmal atrial fibrillation (PAF) patients. Methods: In total, 137 PAF patients were enrolled in the study. Among them, 59 underwent two HBA procedures at 6‐month intervals and 78 patients underwent two CBA sessions, both regardless of atrial fibrillation recurrence. Propensity score matching was performed to estimate similar patient characteristics between the HBA and CBA groups. Results: Each group comprised of 46 matched patients for comparison. The TUA rate at the first session was higher for HBA (49 of 184 PVs) than for CBA (20 PVs) (P =.01), with the highest incidence at the left superior pulmonary vein (LSPV). The rates of PVI durability at the second session performed 7 months later were similar between HBA (168 of 184 PVs) and CBA (162 PVs) groups. The PVI durability rate at the TUA sites of the first session was higher for HBA than for CBA (41 of 49 PVs vs 10 PVs, respectively; P =.01). Fifty percent of the patients underwent HBA at 73°C for the LSPV. HBA performed at 73°C yielded a lower TUA rate than that at 70°C (16 of 23 PVs vs 7 of 23 PVs; P =.008). Conclusions: While PVI durability was similar between HBA and CBA, the TUA rate was higher for HBA than for CBA, especially on the LSPV. For LSPV, HBA at a balloon temperature of 73°C may reduce the TUA rate. [ABSTRACT FROM AUTHOR]

Backgrounds: Several studies have shown the serum high sensitive cardiac troponin I (hs‐TnI) a biomarker of myocardium injury, and C‐reactive protein (CRP), a biomarker of inflammation, are associated with worse cardiovascular outcomes. We evaluated the relationship between the hs‐TnI level in patients with paroxysmal atrial fibrillation (PAF) after pulmonary vein isolation (PVI) and atrial fibrillation (AF) recurrence. Methods and Results: We enrolled 263 consecutive PAF patients who underwent PVI from May 2017 to April 2018. We investigated the difference in the relationship between the myocardial injury marker (serum hs‐TnI), inflammatory marker (CRP, white blood cell) at 36 to 48 hours after the PVI, and early or late recurrence of AF (ERAF; <3 months and LRAF; from 3 months to 1 year) between the radiofrequency ablation group (R group) and cryoballoon ablation group (C group). The R group consisted of 147 patients and the C groups consisted of 116 patients. The serum hs‐TnI level in R group was significantly lower than in the C group (2.33 vs 5.08 ng/mL; P <.001), while the CRP was significantly higher in the R group than C group (2.02 vs 1.10 mg/dL; P <.001). The incidences of an ERAF/LRAF were similar between the two groups. Conclusion: Cryoballoon ablation may cause more myocardial injury than radiofrequency catheter ablation, on the contrary, radiofrequency catheter ablation, may cause more inflammation than cryoballoon ablation. However, these phenomena may not affect the recurrence of AF after the PVI in patient with PAF. [ABSTRACT FROM AUTHOR]

Background: It remains unclear whether the curative result of paroxysmal atrial fibrillation (PAF) is a result of pulmonary vein (PV) isolation, PV antrum modification (PVAM), or both. We hypothesized that sufficient antrum modification (PVAM) is as important as PV isolation (PVI) for atrial fibrillation (AF) control and that PVAM can be evaluated by quantified lesion deployment using a force‐sensing catheter. Methods and Results: Patients of symptomatic PAF were randomly assigned 2:1 into a PVAM group or a circumferential PV isolation (CPVI) group. In the PVAM group, circumferential quantitative ablation evaluated by automatical VisiTag module was performed. In the CPVI group, conventional circumferential ablation was performed to achieve the end point of all‐PV isolation. In total, 180 patients with PAF were enrolled and randomly assigned to either the PVAM group (n = 120) or the CPVI group (n = 60). A total of 179 patients successfully underwent ablation. In the PVAM group, 68 patients achieved all PVI (PVAM‐PVI), while 51 did not (PVAM‐non‐PVI). At 18 months, there was no significant difference in the maintenance of sinus rhythm between the PVAM and CPVI groups (84.9 vs 79.7%, P =.382). The PVAM‐PVI subgroup demonstrated a higher arrhythmia‐free survival compared with the PVAM‐non‐PVI subgroup (92.6 vs 74.5%, P =.006) and the CPVI group (92.6 vs 79.7%, P =.036). Conclusions: The trial shows that sufficient force‐sensing guided PVAM can result in satisfying outcomes in PAF patients. Notably, sufficient PVAM with all‐PV isolated will further increase the success rate. [ABSTRACT FROM AUTHOR]

Introduction: Pulmonary vein isolation (PVI) using cryoballoon is effective for patients with paroxysmal atrial fibrillation (PAF); however, few reports have evaluated the non‐pulmonary vein (PV) foci after cryoballoon ablation. We aimed to evaluate the characteristics of non‐PV foci and predictors of atrial fibrillation (AF) recurrence after cryoballoon ablation. Methods and Results: This was a single‐center retrospective study of 647 patients with PAF who underwent initial PVI using a second‐generation cryoballoon. After PVI, all patients underwent high‐dose isoproterenol infusion to assess the existence of non‐PV foci. Non‐PV foci were observed in 211 patients (32.6%), which were most frequently observed in the superior vena cava. Higher age (odds ratio [OR] = 1.02; 95% confidence interval [CI] = 1.00‐1.04; P =.025), female sex (OR = 1.65; 95% CI = 1.13‐2.41; P =.009), and lower body mass index (OR = 0.95; 95% CI = 0.89‐1.00; P =.049) were significantly associated with non‐PV foci. The existence of non‐PV foci was an independent predictor of AF recurrence (Hazard's ratio = 1.70; 95% CI = 1.12‐2.60; P =.014). When non‐PV foci were mappable and successfully ablated, patients with non‐PV foci showed similar outcomes with those without non‐PV foci (1‐year AF‐free survival rates of 88.5% vs 91.5%; P =.338). Conversely, when we failed to detect and eliminate non‐PV foci because they had multiple origins and were not consistently inducible (multichanging non‐PV foci), the 1‐year AF‐free survival rate was 56.4% even after substrate modification. Conclusion: Non‐PV foci were observed in one‐third of patients with PAF after cryoballoon ablation and were associated with AF recurrence. Catheter ablation for non‐PV foci was effective when they were mappable; however, multichanging non‐PV foci were associated with worse prognosis. [ABSTRACT FROM AUTHOR]

Background: We present a new, easily applicable approach for the guidance of cryoballoon (CB) pulmonary vein isolation (PVI) procedures that use the combination of a 3D‐mapping system image integration module and computed tomographic (CT)–derived anatomy. The aim of this retrospective, nonrandomized study was to investigate: (a) an alternative use for an established radiofrequency image integration module for cryo procedures; (b) a guidance technology for cryo PVI based on integrated CT anatomy; and (c) its clinical impact. Methods and results: CT left atrium–angiography was performed in 50 consecutive patients before a CB PVI procedure, and a 3D reconstruction of the cardiac anatomy was segmented. A total of 25 patients were treated using conventional fluoroscopy; 25 patients were treated using the 3D image integration technique. In the image integration group, the CARTO3 UNIVU (Biosense Webster) module was used for image integration of 3D anatomy and fluoroscopic imaging. Transseptal puncture and cryo PVI were guided by 3D‐overlay imaging. Procedures were feasible without complications in all patients and cryo PVI procedures were successfully guided using the image integration technique. The intraprocedural time needed to perform image integration was 37 ± 10 seconds. Fluoroscopy time was 31.7 ± 11.7 minutes in the conventional group and 20.1 ± 7.9 minutes in the image integration group (P < .001), procedure time was 116.3 ± 29.0 minutes in the conventional group vs 101.2 ± 20.9 minutes in the 3D group (P = .04). Conclusion: 3D‐overlay guidance of CB PVI is feasible, safe, and applicable in real time with minimal effort. It may significantly reduce radiation exposure by introducing 3D information, known from electroanatomic mapping systems, into cryo PVI procedures. [ABSTRACT FROM AUTHOR]

Background: It has been shown that transmitral A‐wave (TMAW) is affected in paroxysmal atrial fibrillation (PAF), and decreased left atrial contractions cause a decrease in the TMAW velocity. The relationship between TMAW acceleration time (TMAW‐AccT) and PAF is unknown. In this study, the predictive value of TMAW‐AccT for PAF was investigated. Methods: Seventy PAF patients (mean age: 57.8 ± 11.0 years) and 70 control patients (mean age: 58.1 ± 10.5 years) were included in the study. Transthoracic echocardiography was performed in sinus rhythm in all patients. For TMAW‐AccT, the time between the basal point of the A‐wave and the highest point reached was measured. Results: Transmitral A‐wave ‐AccT was significantly longer in the PAF group than the control group (TMAW‐AccT; 88.5 ± 18.1 vs 77.2 ± 16.4 ms, P = .000, respectively). The left atrial diameter and the left atrial volume index were similar between the groups (P = .07, P = .18, respectively). According to a multivariate logistic regression analysis, the TMAW‐AccT (OR: 1.02, 95% confidence interval 1.02–1.07, P < .001) was a predictor of PAF. A receiver operating characteristic curve analysis showed a cutoff value of TMAW‐AccT of >82 ms (sensitivity: 65.7%, specificity: 64.3%, positive predictive value: 64.8%, negative predictive value: 65.2%). Conclusion: Transmitral A‐wave‐AccT can be used as an early marker in detecting PAF without dilated left atrium. [ABSTRACT FROM AUTHOR]

Background: This study aimed to evaluate the effect of substrate modification in paroxysmal atrial fibrillation (AF) patients prior to circumferential pulmonary vein isolation (CPVI). Methods: Patients without left atrial low‐voltage and/or scar areas were defined as Group A. Patients with left atrial low‐voltage and/or scar areas underwent regular CPVI (Group B) or substrate modification after CPVI (Group C). The procedural success rate and differences in the left atrial diameter (LAD) among groups were compared at 1 year postoperatively. Results: The procedural success rate in Group C was comparable to that in Group A (P > 0.05) and was significantly higher than that in Group B (P < 0.01). The LAD of patients in Groups A and C significantly decreased at 1 year postoperatively compared to that prior to the surgery (P < 0.05). However, no significant difference was noted in Group B. Conclusions: Our study demonstrated that substrate modification could contribute to the single catheter ablation surgery success rate in patients with paroxysmal AF and narrow LAD. [ABSTRACT FROM AUTHOR]

Background Catheter ablation (CA) for atrial fibrillation (AF) is preferred for paroxysmal AF (PAF) but selectively performed in patients with persistent AF (PersAF). This study aimed to investigate the prognostic differences and consequences of CA based on the AF type. Methods and Results Data from a multicenter AF cohort study were analyzed, categorizing patients as PAF or PersAF according to AF duration (≤7 or >7 days, respectively). A composite of all-cause death, heart failure hospitalization, stroke, and bleeding events during 2-year follow-up and changes in the Atrial Fibrillation Effect on Quality-of-life score were compared. Additionally, propensity score matching was performed to compare clinical outcomes of patients with and without CA in both AF types. Among 2788 patients, 51.6% and 48.4% had PAF and PersAF, respectively. Patients with PersAF had a higher incidence of the composite outcome (12.8% versus 7.2%; P <0.001) and smaller improvements in Atrial Fibrillation Effect on Quality-of-life scores than those with PAF. After adjusting for baseline characteristics, PersAF was an independent predictor of adverse outcomes (adjusted hazard ratio, 1.35 [95% CI, 1.30-1.78], P =0.031) and was associated with poor improvements in Atrial Fibrillation Effect on Quality-of-life scores. Propensity score matching analysis showed that the CA group had significantly fewer adverse events than the medication group among patients with PAF (odds ratio, 0.31 [95% CI, 0.18-0.68]; P =0.002). Patients with PersAF showed a similar but nonsignificant trend. Conclusions PersAF is a risk factor for worse clinical outcomes, including patients' health status. CA is associated with fewer adverse events, although careful consideration is required based on the AF type.

Objective: We tested whether ablation methodology and study design can explain the varying outcomes in terms of atrial fibrillation (AF)‐free survival at 1 year. Background: There have been numerous paroxysmal AF ablation trials, which are heterogeneous in their use of different ablation techniques and study design. A useful approach to understanding how these factors influence outcome is to dismantle the trials into individual arms and reconstitute them as a large meta‐regression. Methods: Data were collected from 66 studies (6941 patients). With freedom from AF as the dependent variable, we performed meta‐regression using the individual study arm as the unit. Results: Success rates did not change regardless of the technique used to produce pulmonary vein isolation (PVI). Neither was adjunctive lesion sets associated with any improvement in outcome. Studies that included more males and fewer hypertensive patients were found more likely to report better outcomes. The electrocardiography method selected to assess outcome also plays an important role. Outcomes were worse in studies that used regular telemonitoring (by 23%; P < 0.001) or in patients who had implantable loop recorders (by 21%; P = 0.006), rather than those with the less thorough periodic Holter monitoring. Conclusions: Outcomes of AF ablation studies involving PVI are not affected by the technologies used to produce PVI. Neither do adjunctive lesion sets change the outcome. Achieving high success rates in these studies appears to be dependent more on patient mix and on the thoroughness of AF detection protocols. These should be carefully considered when quoting the success rates of AF ablation procedures that are derived from such studies. [ABSTRACT FROM AUTHOR]

Purpose: The availability of dual Doppler echocardiography (DDE), which facilitates the simultaneous recording of Doppler waveforms at two different sites, has enhanced ability to assess single-beat atrial mechanical delay. We sought to investigate the predictive value of intra-left atrial mechanical delay for atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) with DDE.Methods: Eighty-six patients with paroxysmal AF scheduled to undergo RFCA were prospectively enrolled. Intra-atrial and interatrial mechanical delays were evaluated by DDE and traditional tissue Doppler imaging (tTDI), respectively. The time of whole analysis process with each method was recorded. After RFCA, patients were followed for 1 year.Results: Thirty (34.88%) patients had AF recurrence, and 56 (65.12%) patients maintained sinus rhythm. Cut-off values of 39.38 ms for intra-left atrial mechanical delay obtained by DDE and 32.70 ms by tTDI predicted AF recurrence. Areas under curves were comparable in receiver operator characteristic analysis (P > .05). The whole analysis time of DDE was less than tTDI. Parameters obtained by DDE had better reproducibility.Conclusion: Intra-left atrial mechanical delay best predicted 1-year AF recurrence after RFCA. Compared with tTDI, DDE can noninvasively assess single-beat atrial mechanical delay with high predictive power, less analysis time, and better reproducibility. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Left atrium (LA) systolic dysfunction is observed in the early stages of atrial fibrillation (AF) prior to LA anatomical change. We investigated whether LA systolic dysfunction predicts recurrent AF after catheter ablation (CA) in patients with paroxysmal AF. Methods and results: We studied 106 patients who underwent CA for paroxysmal AF. LA systolic function was assessed with the LA emptying volume = Maximum LA volume (LAVmax) – Minimum LA volume (LAVmin), LA emptying fraction = [(LAVmax – LAVmin)/LAVmax] × 100, and LA ejection force calculated with Manning's method [LA ejection force = (0.5 × ρ × mitral valve area × A2)], where ρ is the blood density and A is the late‐diastolic mitral inflow velocity. Recurrent AF was detected in 35/106 (33%) during 14.6 ± 9.1 months. Univariate analysis revealed reduced LA ejection force, decreased LA emptying fraction, larger LA diameter, and elevated brain natriuretic peptide as significant variables. On multivariate analysis, reduced LA ejection force and larger LA diameter were independently associated with recurrent AF. Moreover, patients with reduced LA ejection force and larger LA diameter had a higher risk of recurrent AF than preserved LA ejection force (log‐rank P = 0.0004). Conclusions: Reduced LA ejection force and larger LA diameter were associated with poor outcome after CA for paroxysmal AF, and could be a new index to predict recurrent AF. [ABSTRACT FROM AUTHOR]

Background The mechanisms underlying self-perpetuation of persistent atrial fibrillation (AF) are not well understood. To gain insight into these mechanisms, we conducted a study comparing left atrial (LA) electroanatomic maps obtained during sinus rhythm between patients with paroxysmal AF (PAF) and patients with persistent AF (PerAF). Methods The study included 23 men with PAF (age, 56.3±12.1 years) and 13 men with PerAF (age, 54.3±13.4 years). LA voltage mapping was performed during sinus rhythm. The clinical and electroanatomic characteristics of the two groups were evaluated and analyzed statistically. Results The bipolar voltages at the LA septum, roof, and posterior wall, right superior pulmonary vein (PV) and its antrum, right superior PV carina, and right inferior PV antrum were significantly lower in patients with PerAF than in those with PAF. The bipolar voltages in other parts of the LA did not differ statistically between the two groups. Conclusion PAF and PerAF seem to be characterized by differences in the regional voltage in the LA and PVs. The LA structural remodeling of PerAF may initiate from the right PVs and their antra and LA septum, roof, and posterior wall. [ABSTRACT FROM AUTHOR]

Background and objective Contact force (CF) sensing is a novel technology used for catheter ablation of atrial fibrillation (AF). We compared the single procedure success of CF-guided pulmonary vein isolation (PVI) with that of non-CF guided PVI during a 3-year (1,095 days) follow up period and analyzed the pattern of pulmonary vein (PV) reconnection. Methods A cohort of 167 subjects (68 CF vs. 99 non-CF) with paroxysmal AF were included in the study. Atrial arrhythmia (AA) recurrence was defined as documented AF, atrial flutter, or atrial tachycardia lasting >30 seconds and occurring after 90 days. Results Subjects in the CF group showed a statistically nonsignificant improvement in AA free survival compared to those in the non-CF group (66.2% vs. 51.5%; P value: 0.06). A greater propensity for reconnection was noted around the right-sided PVs compared to left-sided PVs related in both catheter ablation groups. For example, in the CF group 36% of right-sided segments reconnected compared to 16% of left-sided segments (P value <0.01). Conclusions A greater propensity for reconnection was noted around the right sided PV segments in both the CF and non-CF groups. The explanation for this finding was related to greater catheter instability around the right sided veins. Further research is needed to explore the utility of a 'real-time' composite indicator that includes RF energy, CF and catheter stability in predicting transmural lesion formation during catheter ablation. [ABSTRACT FROM AUTHOR]

Introduction Pulmonary vein isolation (PVI) using a cryoballoon (CB) is a useful tool for treating atrial fibrillation (AF); however, the clinical efficacy of the CB has never been fully investigated in patients with a left common pulmonary vein (LCPV). Methods and results Three hundred twenty-four consecutive paroxysmal AF patients underwent PVI with a CB. Three-dimensional computed tomography was performed in all patients before the ablation. The clinical outcomes of the AF ablation between patients with (Group A) and without an LCPV (Group B) were compared. An LCPV was observed in 27 (8%) patients. There were no significant differences in the procedure time (149 ± 45 min vs. 143 ± 40 min, respectively; P = 0.42) and percentage needing touch up ablation between the 2 groups (26% vs. 20%, respectively; P = 0.45). At a mean follow-up of 454 ± 195 days, 282 of 324 (87%) patients were free from any atrial tachyarrhythmias (ATs) after a single procedure. Twenty out of 27 (74%) Group A patients and 262 of 297 (88%) Group B patients were free from ATs (15-month Kaplan-Meier event free rate estimates, 77% and 89%, respectively; P = 0.02). A multivariate analysis identified the presence of an LCPV and the left atrial diameter as reliable predictors of recurrent ATs. Conclusions The long-term clinical outcomes of ablation of AF with the CB was worse in patients with an LCPV than in those without. The presence of an LCPV and the LA size seemed to be reliable predictors of a worse outcome. [ABSTRACT FROM AUTHOR]

Early and Late Recurrences in AF Cryoablation Introduction Recurrences within the blanking period (early recurrences) are common after atrial fibrillation (AF) ablation by pulmonary vein isolation (PVI), but their clinical significance is still controversial. We aimed at evaluating the significance of within-blanking recurrences at 12-month follow-up after cryoballoon (CB) PVI, and to assess the real procedural success rate by continuous monitoring of cardiac rhythm. Methods and Results Sixty consecutive AF patients (34 paroxysmal, 56.7%) underwent their first CB-PVI at one Italian center (May 2013 to April 2015), and subsequent implantation of an implantable loop recorder (ILR). Overall, 12-month success rate after the blanking period was 55%. The shortest detected event was 7 minutes long. Late recurrences were more frequent in non-paroxysmal (19/26, 73.1%) than in paroxysmal AF (8/34, 23.5%; P <0.001). Early recurrences occurred in 17 (28.3%) patients, with 14 also having late recurrences (82.3%), while only 13 out of 43 (30.2%) without within-blanking recurrences experienced post-blanking events (P <0.001). Overall, early recurrences showed 51.8% sensitivity (95% CI 31.9-71.3%) and 90.9% specificity (95% CI 75.7-98.1%) for later recurrences, with 82.3% (95% CI 56.6-96.2%) positive and 69.8% (95% CI 53.9-82.8%) negative predictive value. The positive likelihood ratio was 5.7 (95% CI 1.8-17.8). At multivariable analysis, non-paroxysmal AF (HR: 3.113; 95% CI 1.309-7.403; P = 0.010) and within-blanking recurrences (HR: 3.453; 95% CI 1.544-7.722; P = 0.003) were independent predictors of post-blanking AT/AF. Conclusion CB-PVI for paroxysmal AF shows a 12-month success rate of 76.5% after one single procedure, as assessed by continuous cardiac rhythm monitoring. Within-blanking recurrences predict the ablation failure in more than 80% of patients. [ABSTRACT FROM AUTHOR]

Background For repeat treatment with paroxysmal atrial fibrillation (PAF) recurrence, gap-closure at pulmonary vein ostia alone is not enough. Many recent studies indicated that ganglionated plexi (GPs) denervation could reduce the recurrence of AF. However, it is unclear whether the clinical outcomes of additional GP ablation plus pulmonary veins (PVs ) reisolation during a repeat procedure were associated with less recurrence in PAF patients. The purpose of this study was to evaluate if a repeat procedure of GP ablation (GPA) combining repeated procedure of pulmonary vein isolation (re-PVI), i.e., gap-closure, can offer additional benefit for patients with PAF recurrence. Method A total of 123 consecutive patients with PAF recurrence who underwent success repeat procedures were retrospectively analyzed in our center (2014-2015). Note that 64 patients (group 1, GPA group) were performed with GPA plus re-PVI, while 59 patients (group 2, re-PVI group) had re-PVI (gap-closure) alone. Organized atrial tachycardias (OATs) documented or induced at the end of the procedure were all mapped and ablated. Patients were scheduled for a 12-month follow-up. Clinical presentation and outcome data for the two groups were assessed. Result At the 12-month follow-up 58 of 64 patients (90.6%) in group 1 and 46 of 59 patients (78%) in group 2 remained in sinus rhythm (SR) off antiarrhythmia drugs (AADs) (P = 0.045). Conclusion GPA conferred incremental benefit when performed in addition to re-PVI in patients with PAF recurrence; the GPA group yielded higher success rates than the re-PVI group. [ABSTRACT FROM AUTHOR]

Surface ECG f Wave Analysis X Introduction Dominant frequency (DF) analysis of electrocardiograms (ECGs) from patients with paroxysmal (PAF) and persistent (PeAF) atrial fibrillation has identified higher DFs in PeAF. We therefore hypothesized that among patients initially presenting to the emergency department (ED) with new onset AF, surface ECG features could differentiate PeAF from PAF. Methods and Results Initial 12-lead ECGs from patients presenting to the ED with a first episode of symptomatic AF were analyzed. Following QRS-T subtraction, fast Fourier transform (FFT) analysis of the AF fibrillatory waves was performed to measure DF and organization index (OI). Median DF of all leads and the DF in the lead with maximum OI were determined. Maximum f wave amplitude and vector magnitudes were measured. One hundred sixty-one patients (age 59 ± 16 years, 68% men) were included in this analysis, of whom 96 (58%) spontaneously converted to sinus rhythm within 7 days (PAF group). The remaining 65 patients underwent cardioversion or remained in AF (PeAF group). ECG features (DF, OI, f wave amplitude, and vector magnitude) did not differ among PAF and PeAF patients. Conclusions ECG features (DF, OI, amplitude, vector magnitude) do not differ among patients with PAF versus PeAF when the ECGs are obtained at the initial onset of symptoms. Thus, prior data showing higher DF in PeAF likely reflect electrophysiologic remodeling rather than a marker for any specific type of AF or extent of underlying substrate. [ABSTRACT FROM AUTHOR]

Background Pulmonary vein isolation (PVI) is a cornerstone of catheter ablation in patients with paroxysmal atrial fibrillation (PAF), and balloon-based ablation has been recently performed worldwide. Ablation using the second-generation cryoballoon (CB2) (Arctic Front Advance TM , Medtronic, MN, USA) is useful for PVI; however, there is some debate concerning the optimal freezing time and number of cycles after PVI is achieved. Methods The AD-Balloon study was designed as a prospective, multicenter, randomized clinical trial to evaluate the optimal strategy (freezing cycles) of CB2 ablation (UMIN Clinical Trials Registry UMIN000020130). The main objective of this study is to investigate the need for an additional freezing cycle after PVI in patients treated with CB2 ablation. Patients will be randomly assigned in a 1:1 ratio to treatment with additional freezing (AD group) or without additional freezing (non-AD group). In the AD group, 3 min of additional freezing time will be applied in all pulmonary veins after PVI is confirmed at the previous freezing cycle. In the non-AD group, no additional freezing will be applied in all pulmonary veins after PVI is confirmed. The primary endpoint of this study is the occurrence of atrial tachyarrhythmias within a 1-year follow-up period. We will enroll 110 consecutive patients with PAF. We will also investigate the usefulness of delayed-enhancement magnetic resonance imaging to assess the ablation lesions caused by CB2 ablation. Results The results of this study are currently under investigation. Conclusion The AD-Balloon study would assess the need for an additional freezing cycle after PVI is achieved. Our findings may contribute to further improvement of the CB2 ablation procedure. [ABSTRACT FROM AUTHOR]

Empiric Thoracic Vein Isolation Introduction The guidelines suggest that an adjuvant substrate modification in addition to pulmonary vein isolation (PVI) may be needed for persistent atrial fibrillation (PerAF) assuming that catheter ablation is less successful for PerAF than paroxysmal AF (PAF). To revisit the above assumption, we compared the outcome of the same catheter ablation strategy between PAF and PerAF. Methods and Results Two hundred and thirty-three consecutive patients (mean age 60 ± 10 years, 53 PerAF and 8 long-lasting PerAF) without structural heart disease underwent catheter ablation of AF by the same strategy using an empiric thoracic vein isolation (a wide circumferential PVI plus empiric superior vena cava isolation) as a major part of the strategy without any adjuvant substrate modification. The duration of AF in the patients with PerAF was 6 ± 4 months. During 25 ± 10 months of follow-up after single procedures, 71 (30%) patients had atrial tachyarrhythmia recurrences without antiarrhythmic drugs. A Kaplan-Meier analysis of the recurrence-free survival rate after a single procedure and after repeat procedures revealed no significant difference between the patients with PAF and those with PerAF (log-rank, P = 0.38 and P = 0.27, respectively). A Cox regression multivariate analysis of the variables including the age, gender, PerAF, body mass index, left ventricular ejection fraction, and left atrial volume index demonstrated that none of the variables were an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure. Conclusion In patients without underlying heart disease, the procedural outcome of an empiric thoracic vein isolation is comparable for PAF and PerAF. [ABSTRACT FROM AUTHOR]

Single 3 vs. Double 4 Strategy in CB ablation Introduction Second-generation cryoballoon (CB-Adv) ablation is highly effective in achieving pulmonary vein isolation (PVI) with promising mid-term clinical outcome. However, the ideal freezing strategy is still under debate. The aim of this study was to assess the efficacy of a single 3-minute approach compared to the conventional 4-minute plus bonus application using CB-Adv. Methods and Results One hundred and sixty patients (67% male; mean age 58.0 ± 13.3 years) underwent PVI using CB-Adv for paroxysmal atrial fibrillation (PAF). Among 160 patients, 80 received a single 3-minute approach (3-mns group), while the remaining 80 conventional 4-minute plus bonus-freeze (4-mns group). Mean procedure and fluoroscopy times were 90.6 ± 15.8 and 18.3 ± 6.9 in the 4-mns group, 75.2 ± 17.1 and 13.5 ± 8.7 in the 3-mns group (P < 0.001, respectively). First-freeze isolation rate was 91.6% in the 4- versus 90.6% in the 3-mns group (P = 0.78). Persistent phrenic nerve palsy (PNP) occurred in 6/80 (3.5%) in the 4-mns group and 4/80 in the 3-mns group (P = 0.75). The overall freedom from ATas 2 years after the procedure was 78.1% (125/160): 77.5% (62/80 patients) in the 3-mns and 78.8% (63/80 patients) in the 4-mns group (P = 0.82). In multivariate analysis, time to PVI and nadir temperature independently predicted ATa recurrences (P < 0.001). Conclusions CB-Adv ablation for PAF is highly effective, resulting in 78% 2-year freedom from arrhythmic recurrences. A 'single 3-minute strategy' showed equal efficacy as compared to the conventional 4-minute plus bonus freeze approach at 2-year follow-up, providing shorter procedure and fluoroscopy time. Nadir temperature and time to PVI were predictors of arrhythmic recurrences. 'Bonus-freeze' strategy might be unnecessary. [ABSTRACT FROM AUTHOR]

Low-Power Ablation of AF Using the nMARQ Catheter Introduction The circular irrigated decapolar nMARQ ablation catheter designed for treating atrial fibrillation (AF) has recently been recalled following two deaths due to esoatrial fistula. Injury to the esophagus has been previously reported in up to 50% of patients using 20-25 W unipolar radiofrequency (RF) energy. Low power of 15 W has been proposed to prevent this complication, but the efficacy of this strategy to avoid AF recurrence is unknown. Methods and Results Consecutive patients with drug-refractory, symptomatic AF were included. Under electroanatomical navigation, the nMARQ catheter was used to isolate all PVs by applying 15 W of unipolar RF simultaneously from up to 10 poles during 40 seconds. Multiple applications were used for each vein, until isolation was achieved. Follow-up was performed after a 2-month blanking period. A total of 50 patients (37 males, age 58 ± 10 years) were included. All PVs were acutely isolated without requiring touch-up by conventional ablation catheters. Pericardial effusion occurred in two patients, of whom one required periocardiocentesis. Right phrenic nerve palsy occurred in another patient, which partially resolved. There were no cases of esophageal fistula or stroke. After a follow-up of 15±4 months, AF recurred in 27/50 (54%) patients. Conclusion The recurrence rate of AF with 15 W unipolar applications is high. Despite use of low power, complications such as pericardial effusion and phrenic nerve palsy may occur. [ABSTRACT FROM AUTHOR]

Background Knowledge of the onset of atrial fibrillation (AF) episodes in patients with paroxysmal atrial fibrillation (PAF) will enable them to better manage this condition. Current advances in mobile technology allow RR interval data to be obtained in real time. An analysis technique using RR interval data is presented with a view to alert a subject before a PAF episode. Method The method is based on a time series of standard deviation and 0.99 quantile values of the spectral entropy, constructed from RR data. The RR data are taken from three time periods. The first time period has no occurrences of AF for 45 min to either side of the time period. The second time period just precedes an AF attack. Both of these are of thirty minutes duration. The third time period of approximately 5 min follows the second, and is when AF occurs. Results Twenty-two PAF subjects were studied and in all cases there was a steady increase in the values of these indices as the onset of the AF attack approached. Conclusion This method of analysis of RR interval data shows potential use to alert a PAF subject before the onset of an AF episode. [ABSTRACT FROM AUTHOR]

Primary Persistent AF. Introduction: Persistent atrial fibrillation (persAF) can occur either as a sustained arrhythmia that has progressed from initially paroxysmal AF or as primary persAF without a history of any spontaneously terminated episode. There is a paucity of data differentiating between the 2 different persAF entities. Thus, we prospectively evaluated baseline characteristics, electrophysiological features, and ablation outcome in these 2 patient cohorts. Methods and results: A total number of 154 consecutive persAF patients (63 ± 10 years, f = 42, longstanding persAF = 60) were characterized in terms of having primary persAF (P-persAF group) or persAF that secondarily progressed from paroxysmal AF (S-persAF group). All patients underwent de novo catheter ablation using the stepwise approach. PersAF entities were characterized by detailed patient history, sequential Holter monitoring, and reports of documented modes of AF conversion, respectively. The P-persAF group had a higher number of young patients (<50 years), a shorter AF history, and a higher number of congestive heart failure. The HATCH score did not differ between the groups. Procedural AF termination rate was significantly higher in S-persAF than in P-persAF patients (n = 55 [81%] vs. n = 58 [68%], P = 0.043). At 1-year follow-up, the arrhythmia-free survival after a single procedure was significantly lower in patients with P-persAF (26% vs. 43%, P = 0.016). Categorization to P-persAF was the strongest independent predictor of arrhythmia recurrence. Conclusions: P-persAF seems to be a specific arrhythmia entity that is associated with a lower AFtermination rate and a worse outcome after catheter ablation as compared to S-persAF. [ABSTRACT FROM AUTHOR]

Loss of Pace Capture and Dormant Conduction in PVI Introduction Permanent pulmonary vein isolation (PVI) remains an essential goal of ablation therapy in patients with atrial fibrillation. Aim of this study was the intraindividual comparison of unexcitability to pacing along the ablation line versus dormant conduction (DC) as additional procedural endpoints. Methods A total of 58 patients with paroxysmal atrial fibrillation (PAF) underwent PVI by circumferential ablation of ipsilateral pulmonary veins (PVs), followed by testing for DC by adenosine administration. Irrespective of the presence of DC, pacing along the ablation line for left atrium capture was performed and additional radio frequency energy applied if necessary. PVs with initial DC were retested after achieving unexcitability. Results PVI was achieved in 224 of 224 PVs. In 33 of 224 PVs (15%) DC was revealed. At 92 of 112 ablation lines (82%) sites of excitability were found. Three (9%) of the initial 33 PVs with DC showed further DC after achieving unexcitability at repeated testing. Thirty-two of 33 assumed areas of unmasked PV-LA reconduction as revealed by DC-testing showed a corresponding site of excitability on the ablation line. After a follow-up of 11.6 ± 3.4 months 79% of patients were free of arrhythmia. Conclusions Pacing for unexcitability can safely identify potential sites of DC and even sites that would have not been detected by testing for DC. Unexcitability, therefore, serves as a suitable and safe procedural endpoint not only for patients with contraindications to adenosine administration. Our data suggest that adenosine may be expendable when achieving unexcitability along the ablation line. [ABSTRACT FROM AUTHOR]

Background There is growing interest in detecting paroxysmal atrial fibrillation (PAF) to identify patients at high risk of thromboembolic stroke. The implantable loop recorder (ILR) is emerging as a powerful new tool in the diagnosis of PAF. Widespread implantation has significant cost implications and their use must be targeted at those patients at most risk. Methods We retrospectively studied a population of 200 adult patients who underwent ILR implantation for the investigation of syncope or palpitations. Clinical data, baseline electrocardiogram (ECG) characteristics, and echocardiographic data were collected. All ECGs and electrograms (EGMs) were scrutinized by two blinded investigators. PAF incidence was defined as episodes lasting >30 seconds on EGMs recorded in ILR memory. Results Our ILR population consists of 200 patients, 111 (56%) male, with a mean age of 61.4 years (range 19-95). PAF was detected in 42 patients. The following factors were significant predictors of PAF by multivariate logistic regression analysis: cigarette smoking (odds ratio [OR] = 3.73, 95% confidence interval [CI] = 1.40-10.24, P = 0.009) and incomplete right bundle branch block (IRBBB; OR = 9.04, 95% CI = 2.51-34.64, P = 0.00088). Significant differences included incidence of IRBBB (P = 0.012), cigarette smoking (P = 0.026), hypercholesterolemia (P = 0.015), age (P = 0.002), estimated glomerular filtration rate (P = 0.031), left atrial volume (P = 0.019), and PR interval (P = 0.031). The PAF group had significantly higher CHA2DS2-VASc scores (P = 0.01). Conclusions Our study reports predictive factors for PAF in an ILR population. We suggest that cigarette smoking and IRBBB are independently associated with paroxysmal AF in patients presenting with palpitations or syncope. [ABSTRACT FROM AUTHOR]

Background: The study of atrial conduction defects associated with the onset of paroxysmal atrial fibrillation (PAF) can be addressed by analyzing the P wave from the surface electrocardiogram (ECG). Traditionally, signal-averaged ECGs have been mostly used for this purpose. However, this alternative hinders the possibility to quantify every single P wave, its variability over time, as well as to obtain complimentary and evolving information about the arrhythmia. This work analyzes the time progression of several time and frequency P wave features as potential indicators of atrial conduction variability several hours preceding the onset of PAF.Methods: The longest sinus rhythm interval from 24-hour Holter recordings of 46 PAF patients was selected. Next, the 2 hours before the onset of PAF were extracted and divided into two 1-hour periods. Every single P wave was automatically delineated and characterized by 16 time and frequency metrics, such as its duration, absolute energy in several frequency bands and high-to-low-frequency energy ratios. Finally, the P wave variability over each 1-hour period was estimated from the 16 features making use of a least-squares linear fitting. As a reference, the same parameters were also estimated from a set of 1-hour ECG segments randomly chosen from a control group of 53 healthy subjects age-, gender-, and heart rate-matched.Results: All the analyzed metrics provided an increasing P wave variability trend as the onset of PAF approximated, being P wave duration and P wave high-frequency energy the most significant individual metrics. The linear fitting slope α associated with P wave duration was (2.48 ± 1.98)×10(-2) for healthy subjects, (23.8 ± 14.1)×10(-2) for ECG segments far from PAF and for (81.8 ± 48.7)×10(-2) ECG segments close to PAF p = 6.96×10(-22) . Similarly, the P wave high-frequency energy linear fitting slope was (2.42 ± 4.97)×10(-9) , (54.2 ± 107.1)×10(-9) and (274.2 ± 566.1)×10(-9) , respectively (p = 2.85×10(-20) ). A univariate discriminant analysis provided that both P wave duration and P wave high-frequency energy could discern among the three ECG sets with diagnostic ability around 80%, which was improved up to 88% by combining these metrics in a multivariate discriminant analysis.Conclusion: Alterations in atrial conduction can be successfully quantified several hours before the onset of PAF by estimating variability over time of several time and frequency P wave features. [ABSTRACT FROM AUTHOR]