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Abstract: Aims: To evaluate the incidence of newly diagnosed intracardiac thrombi (ICT) in respect to the mode of OAC in patients undergoing cardioversion (CV). Methods and results: We prospectively assessed transesophageal echocardiography (TEE) and OAC therapy prior to CV in AF patients with ≥48‐hour duration scheduled for CV. A total of 60 first‐time ICT (4.7%) were diagnosed in 1,286 TEE, with highest rate in patients without OAC (9.6% vs. OAC 4.1%, P  =  0.009) and an apparently lower rate in nonvitamin K antagonist anticoagulants (NOAC) therapy compared to vitamin K antagonist (VKA) (2.5% vs. 5.3%, P  =  0.02). VKA therapy control 4 weeks prior to CV was overall average (time in therapeutic range 60%) and patients showed more frequently clinical characteristics and TEE parameters associated with risk for ICT. Even among patients with effective OAC therapy (uninterrupted NOAC and VKA therapy with international normalized ratio (INR) ≥2.0 for 3 weeks), ICT occurred in 2.7%, but with no difference between both groups (P  =  0.22). There was no difference between different types of NOAC. Independent predictors for ICT were history of embolism, hypertension, BMI, absence of OAC, renal function, reduced atrial appendage flow, and presence of spontaneous echo contrast. Conclusion: NOAC therapy seems favorable in the overall prevention of ICT, although this is likely to be caused by suboptimal VKA therapy control and differences in the overall health status between VKA and NOAC patients. ICT occurred even with effective OAC therapy suggesting individual TEE‐guided cardioversion in patients at risk. [ABSTRACT FROM AUTHOR]

Background Extensive and repeated substrate modification (SM) is frequently performed as an ablation strategy in persistent atrial fibrillation (persAF). The effect of these extended ablation strategies on atrial function has not been investigated sufficiently so far. The purpose was to assess atrial function by cardiac magnetic resonance (CMR) and its association with left atrial (LA) scar burden by electroanatomical voltage-mapping after multiple persAF ablation procedures. Methods We included 16 persAF patients who had ≥2 SM procedures and a control group (CG) of 21 persAF patients without prior ablation. CMR was performed in sinus rhythm at least 4 weeks after the last cardioversion. Active left and right (RA) atrial emptying fractions (AEF) as well as peak active left atrial appendage (LAA) emptying velocities were obtained by CMR flow measurements. Furthermore, LA scar burden was quantified on electroanatomical voltage maps by the portion of points with local voltage amplitude <0.2 mV. Results We found median LA-AEF to be lower (13 [9-22] vs 32 [26-36] %, P < 0.001) and median LA scar burden to be higher (40 [20-68] vs nine [3-18] %, P < 0.05) in the SM group compared with the CG. Furthermore, a significant correlation was found between mean LA voltage and LA-AEF (r2 = 0.62, P < 0.001). No significant differences were detected with respect to median RA-AEF (41 [28-48] vs 47 [35-50] %, P = 0.43) and median peak LAA emptying velocities (30 [16-40] vs 17 [13-28] cm/s, P = 0.07). Conclusions Active LA function is preserved but significantly impaired and associated with ablation-related LA scar burden after multiple extensive persAF ablations. [ABSTRACT FROM AUTHOR]

Ultra High-Density Mapping of Complex AT Introduction Conventional mapping of complex atrial tachycardias (ATs) can be challenging. Thus, we evaluated feasibility and utility of a novel, ultra high-density 3D mapping approach to characterize and map AT in these cases. Methods and Results Overall, 21 patients (67.4 ± 7.6 years; male: 52.4%, 1.9 ± 1.4 previous ablation procedures) with documented AT referred to our center underwent catheter ablation including ultra high-density mapping using a novel 64-electrode mini-basket catheter and an adjunctive 3D mapping system. A total of 24 AT (20 left atrial, 4 right atrial AT) were analyzed in 19 cases. In 2 patients, map acquisition failed due to scarce local electrograms and unstable AT cycle length, respectively. Underlying mechanisms were focal (n = 3), as well as local (n = 8) and macro (n = 13) reentry tachycardias with a mean cycle length of 311.8 ± 67.7 milliseconds. The analysis of propagation waves, activation and voltage revealed complex activation patterns and allowed for the identification of critical sites of AT initiation or maintenance without the need for further mapping techniques. In all cases critical sites could be verified by successful consecutive ablation. Mean mapping time was 19.4 ± 7.6 minutes, mean number of mapping points was 19,217 ± 10,270. Radiofrequency application until first effect was 165.1 ± 374.2 seconds; total procedure time was 157.6 ± 51.4 minutes, fluoroscopy time 21.7 ± 13.8 minutes, and total radiofrequency duration 1,016 ± 951.9 seconds, respectively. No severe complications occurred. Conclusion Ultra high-density mapping of complex AT is safe and feasible. Further, it enables detailed insight into AT mechanisms. Critical AT sites can be identified precisely in order to guide successful catheter ablation. [ABSTRACT FROM AUTHOR]

Trans-Telephonic ECG Monitoring for the Detection of CA Introduction Diagnosis of infrequent cardiac arrhythmias (CA) is often unsuccessful using resting or Holter ECG. As early detection and treatment of CA, especially atrial fibrillation (AF), has implications on patients' treatment and outcome, we investigated, whether self-guided, trans-telephonic event-recorder monitoring (Tele-ECG) improves diagnosis and influences treatment options. Methods Between 2009 and 2014, 790 patients (54 ± 18 years, 40% male; no history of CA: 582, known AF: 179, other CA: 29) presented with recurrent symptoms suggestive of CA and were screened by Tele-ECG (17.3 ± 26.9 days). A total of 11,775 ECGs were transmitted via a 24-hour telephone hotline including documentation of the respective symptoms. Results In 73% of patients, CA was documented at the time of symptoms: sinus tachycardia 23%, premature ventricular beats 19%, AF 14%, supraventricular tachycardia 9%, sinus bradycardia 5%, sinus arrhythmia 2%, and AV block II 1%. The mean time until the first symptomatic episode occurred was 6.9 ± 15.3 days (median 2.5 days). The first documented arrhythmia occurred on average after 7.7 ± 14.1 days (median 3 days). In patients with AF (n = 110), 44% was newly diagnosed. According to the Tele-ECG diagnosis, AF ablation was performed in 27% of these patients, 7% electrical cardioversion, and in 30% antiarrhythmic therapy was initiated. In 65% of the patients with recurrence of known AF, (re-)ablation was performed or recommended and in 16% antiarrhythmic therapy was modified. Conclusions Tele-ECG monitoring is effective in the diagnosis of suspected symptomatic CA. A diagnosis can usually be achieved within 1 week and has implications on patients' care. [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]

Reduced Radiation Exposure in AF Ablation Introduction Recently, a new image integration module (IIM, CartoUnivu™ Module) has been introduced to combine and merge fluoroscopy images with 3-dimensional-(3D)-electroanatomical maps (Carto® 3 System) into an accurate 3D view. The aim of the study was to investigate the influence of IIM on the fluoroscopy exposure during pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) in a prospective randomized trial. Methods and results Between June and November 2014, a total of 60 patients with PAF (73.3% male, 64.0 ± 9.2 years), who underwent PVI with the endpoint of unexcitability of the ablation line, were randomized to either a conventional 3D mapping system (Carto® 3 System) or to an additional IIM on the basis of an assumed reduction of fluoroscopy exposure by the use of IIM. There were no significant differences in baseline characteristics. The median ablation procedure time was identical in both groups (140.7 ± 27.8 minutes vs. 140.8 ± 39.5 minutes; P = 0.851). A significant decrease of mean fluoroscopy time from 11.9 ± 2.1 to 7.4 ± 2.6 minutes (P < 0.0006) and median fluoroscopy dose from 882.9 to 476.5 cGycm2 (P < 0.001) was achieved. The main reduction of radiation could be realized during creation of the 3D-map. No major complications occurred during the procedures. After a median follow-up of 125.7 ± 45.6 days 80% of the patients were free from any atrial arrhythmias. Conclusion CartoUnivu™ module easily integrates into the workflow of PVI with the endpoint of unexcitability of the ablation line without prolonging the procedure time. It is associated with a marked reduction in fluoroscopic dose when compared to a conventional 3D mapping system. [ABSTRACT FROM AUTHOR]

Acute Complication Rate in AF Ablation Introduction Catheter ablation (CA) has emerged as a widespread therapeutic option in the treatment of atrial fibrillation (AF). Currently, no safety data with regard to the impact of the underlying structural heart diseases (SHD) are available. We sought to assess the risk for acute and long-term complications during CA of AF in relation to underlying SHD. Methods and Results We included 6,211 patients in a prospective registry undergoing CA of AF in 41 nationwide centers. All patients were divided into 4 groups according to the underlying heart disease: No SHD (69.4%), hypertensive heart disease (HHD) (12.0%), coronary artery disease (CAD) (15.1%), and cardiomyopathy (CM) (3.6%). In univariate analysis, patients with HHD had an overall complication rate of 7.28%, whereas patients without an SHD had a significantly lower rate of 6.01% (P < 0.01). Multivariate analysis revealed that HHD (adjusted odds ratio [OR]: 1.97 [95% confidence interval (CI): 1.02-3.83], P = 0.0442) and age (years; OR: 1.04 [95% CI: 1.01-1.07], P = 0.0155) were independent predictors of severe, nonfatal complications and death. Other SHD including CAD (OR: 1.48 (0.73-3.00), P = 0.2797) and CM (OR: 2.37 [0.70-7.99], P = 0.1630) failed to reach statistical significance. Male sex was protective (OR: 0.47 [95% CI: 0.27-0.81], P = 0.0062). Conclusion In general, CA of AF has a low number of severe complications. In our prospective registry HHD emerged as an independent predictor of severe, nonfatal complications during AF ablation but other SHD including CAD and CM did not. The influence of HHD on the complication rate should be considered in patient selection. [ABSTRACT FROM AUTHOR]

Reversible Dysfunction After Persistent AF Ablation Introduction There is a paucity of data on atrial injury following ablation of persistent atrial fibrillation (AF). This study aimed at assessing reversibility of atrial dysfunction after successful persistent AF ablation using cardiovascular magnetic resonance (CMR). Methods and Results CMR was performed during sinus rhythm (SR) in 20 consecutive patients with persistent AF at baseline (BL) within 24 hours after ablation and after 6-month follow-up (FU). Catheter ablation included atrial substrate modification using the stepwise approach following pulmonary vein isolation (PVI) in order to attempt termination of persistent AF. Active left (LA) and right atrial (RA) function were quantified by calculating the active emptying fraction (AEF) from transvalvular flow profiles using velocity encoded (VENC) CMR. LA appendage (LAA) function was quantified by measurements of peak a-wave velocities from flow profiles perpendicular to the LAA orifice. Peri-atrial edema was assessed using black-blood T2-weighted CMR. A significant improvement was found in LA-AEF from 18 (12-26)% at BL to 25 (22-35)% at FU (P = 0.0001). Furthermore, RA-AEF significantly increased from 31 (19-35)% at BL to 40 (35-51)% at FU (P < 0.0001). A significant improvement was also found for LAA a-wave velocities from 45 (31-65) cm/s at BL to 62 (49-75) cm/s at FU (P < 0.01). The area of peri-atrial edema on T2-weighted CMR decreased from 1393 (1098-1797) mm2 at BL to 24 (1-92) mm2 at FU (P < 0.0001). Conclusion CMR demonstrates reversibility of LA, LAA, and RA dysfunction associated with resorption of peri-atrial edema in patients with SR after persistent AF ablation. [ABSTRACT FROM AUTHOR]

Intravenous Electrolytes Increase Success Rate of Cardioversion. Background: External biphasic electrical cardioversion (CV) is a standard treatment option for patients suffering from acute symptoms of atrial fibrillation (AF). Nevertheless, CV is not always successful, and thus strategies to increase the success rate are desirable. Objective: The purpose of this study was to evaluate the effect of intravenously administered K/Mg solution on the biphasic CV energy threshold and success rate to restore sinus rhythm (SR) in patients with AF. Methods: The study consisted of 170 patients with persistent AF. The patients were randomly assigned to undergo biphasic CV either with (n = 84) or without (n = 86) pretreatment with K/Mg solution. An energy step-up protocol of 75, 100, and 150 W (J) was used. Results: Biphasic CV of AF was effective in 81 (96.4%) patients in the pretreatment and 74 (86.0%) patients in the control group (P = 0.005). The effective energy level required to achieve SR was significantly lower in the pretreated group (140.8 ± 26.9 J vs 182.5 ± 52.2 J, P = 0.02). No K/Mg-solution-associated side effects such as hypotension or bradycardia were observed. Conclusion: Administration of K/Mg solution positively influences the success rate of CV in patients with persistent AF. Furthermore, significantly less energy is required to successfully restore SR and therefore K/Mg pretreatment may facilitate SR restoration in patients undergoing CV for AF. (J Cardiovasc Electrophysiol, Vol. 23, pp. 54-59, January 2012) [ABSTRACT FROM AUTHOR]

Background: The presence of impaired left atrial appendage (LAA) function identifies patients who are prone to thrombus formation in the LAA and therefore being at high risk for subsequent cardioembolic stroke. LAA function is typically assessed by measurements of LAA emptying velocities using transesophageal echocardiography (TEE) in clinical routine. This study aimed at evaluating the feasibility of assessing LAA emptying by velocity encoded (VENC) cardiovascular magnetic resonance (CMR). Methods: This study included 30 patients with sinus rhythm (n = 18) or atrial fibrillation (n = 12). VENC-CMR velocity measurements were performed perpendicular to the orifice of the LAA. Peak velocities were measured of passive diastolic LAA emptying (e-wave) in all patients. Peak velocities of active, late-diastolic LAA emptying (a-wave) were assessed in patients with sinus rhythm. Correlation and agreement was analyzed between VENC-CMR and TEE measurements of e- and a-wave peak velocities. Results: A significant correlation and good agreement was found between VENC-CMR and TEE measurements of maximal e-wave velocities (r = 0.61, P < 0.001; mean difference 0 ± 10 cm/s). The a-wave was detectable by VENCCMR in all patients with sinus rhythm. Correlation was also significant for measurements of peak a-wave velocities between VENC-CMR and TEE (r = 0.71, P < 0.001). There was no significant correlation of LAA emptying velocities with clinical characteristics and only a modest negative correlation of passive LAA emptying with LA function. Conclusions: The assessment of active and passive LAA emptying by VENC-CMR is feasible. Further evaluation is required of potential future clinical applications such as risk stratification for cardioembolic stroke [ABSTRACT FROM AUTHOR]