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Aims The multielectrode radiofrequency balloon catheter (RFB) has been developed to achieve safe and effective pulmonary vein isolation (PVI) for atrial fibrillation (AF) ablation. This single-centre study aimed to evaluate the midterm clinical outcome and predictors of single-shot PVI with the novel RFB. Methods and results All consecutive patients with symptomatic paroxysmal or persistent AF undergoing first-time PVI with the RFB were prospectively included. Clinical and procedural parameters were systematically collected. The primary safety endpoint was defined as any major periprocedural complications. The primary efficacy endpoint consisted of freedom from any atrial tachyarrhythmias (ATas) lasting >30 s during the follow-up after a 3-month blanking period. Persistent single-shot PVI was defined as PVI achieved with a single RFB application without acute reconnection. A total of 104 consecutive patients (mean age 64.3 ± 11.4 years, 56.7% males) were included. 15 patients (14.4%) presented with persistent AF. The procedure time was 59.0 min with a dwell time of 20.0 min. One major complication occurred in one patient. At a mean follow-up of 10.1 ± 5.3 months, freedom from ATas was 82.9%. ATas occurred in 14 patients, 11/69 patients (15.9%) with paroxysmal AF and 3/13 (23.1%) with persistent AF. The best cut-offs to predict persistent single-shot PVI were impedance drop >19.2 Ω [area under the receiver operator characteristic curve (AUC) 0.74] and temperature rise >11.1° C (AUC 0.77). Conclusion In a large cohort of patients undergoing PVI with the RFB, the complication rate was 1%. At a mid-term follow-up of 10.1 ± 5.3 months, freedom from ATas was 82.9%. Specific cut-offs of impedance drop and temperature rise may be useful to predict persistent single-shot isolation.

Aims Hybrid atrial fibrillation (AF) ablation is a promising approach in non-paroxysmal AF. The aim of this study is to assess the long-term outcomes of hybrid ablation in a large cohort of patients after both an initial and as a redo procedure. Methods and results All consecutive patients undergoing hybrid AF ablation at UZ Brussel from 2010 to 2020 were retrospectively evaluated. Hybrid AF ablation was performed in a one-step procedure: (i) thoracoscopic ablation followed by (ii) endocardial mapping and eventual ablation. All patients received PVI and posterior wall isolation. Additional lesions were performed based on clinical indication and physician judgement. Primary endpoint was freedom from atrial tachyarrhythmias (ATas). A total of 120 consecutive patients were included, 85 patients (70.8%) underwent hybrid AF ablation as first procedure (non-paroxysmal AF 100%), 20 patients (16.7%) as second procedure (non-paroxysmal AF 30%), and 15 patients (12.5%) as third procedure (non-paroxysmal AF 33.3%). After a mean follow-up of 62.3 months ± 20.3, a total of 63 patients (52.5%) experienced ATas recurrence. Complications occurred in 12.5% of patients. There was no difference in ATas between patients undergoing hybrid as first vs. redo procedure (P = 0.53). Left atrial volume index and recurrence during blanking period were independent predictors of ATas recurrence. Conclusion In a large cohort of patients undergoing hybrid AF ablation, the survival from ATas recurrence was 47.5% at ≈5 years follow-up. There was no difference in clinical outcomes between patients undergoing hybrid AF ablation as first procedure or as a redo.

Background: Brugada syndrome (BrS) is caused by mutations in SCN5A gene in 15%-20% of cases. Previous studies showed worse prognosis in SCN5A mutation carriers (SCN5A+). To date, there are no data on genotype–phenotype correlation with electrocardiographic (ECG) imaging (ECGI) and high-density epicardial electroanatomic map. Objective: This study aimed to correlate SCN5A mutation with substrate severity in BrS assessed by ECGI and high-density electroanatomic map. Methods: All consecutive BrS patients undergoing ECGI and high-density epicardial electroanatomic map with HD Grid Mapping Catheter were retrospectively analyzed. On ECGI, the following parameters were analyzed before and after ajmaline administration: right ventricular outflow tract (RVOT) activation time (RVOT-AT) and RVOT recovery time (RVOT-RT). On electroanatomic map, the parameters analyzed before and after ajmaline were high-frequency potential activation time (HFPat), high-frequency potential duration (HFPd), high-frequency potential amplitude (HFPa), low-frequency potential activation time (LFPat), low-frequency potential duration (LFPd), and low-frequency potential amplitude (LFPa). Results: Thirty-nine BrS patients with ECGI were included. Eight patients (20.5%) were SCN5A+. At baseline ECGI map, mean RVOT-RT was longer in SCN5A+ (P = .024). After ajmaline administration, SCN5A+ patients showed longer RVOT-AT (125.6 vs 100.8 ms; P = .045) and longer RVOT-RT (426.4 vs 397 ms; P = .033). After ajmaline administration, SCN5A+ showed longer HFPat (164.1 vs 119.5 ms; P = .041); longer LFPat (272.7 vs 200.5 ms; P = .018); and longer LFPd (211.9 vs 151.2 ms; P = .033). Conclusion: In BrS, SCN5A+ patients compared with SCN5A– patients exhibit marked depolarization and repolarization abnormalities as assessed by ECGI and epicardial high-density electroanatomic map.

Introduction: Left atrial posterior wall isolation (LAPWI) is often performed in addition to pulmonary vein isolation (PVI) to improve outcome in patients with persistent atrial fibrillation (AF). In this setting, LAPWI + PVI using cryoballoon ablation had comparable results with radiofrequency ablation (RFA). The aim of the study is to evaluate the feasibility and safety of a new cryoballoon ablation system in PVI + LAPWI isolation, comparing it with the historical platform. Methods: The study was a prospective, non-randomized, single center study. Forty consecutive patients, undergoing PVI + LAPWI with the novel POLARx™, were compared to 40 consecutive patients who underwent the same procedure with the established Arctic Front Advance PRO™. Results: Acute isolation was achieved in all PVs in both groups and LAPWI was achieved in 38 patients (95%) in the POLARx group and in 36 patients (90%) in Arctic Front group. Procedural outcomes were similar between the two groups, except for lower temperatures during cryoapplications in the POLARx group, for both PVI and LAPWI. The complication rate was low and similar between groups. Conclusion: LAPWI+PVI with the novel POLARx™ Cryoballoon is feasible and safe; the results are comparable with the Arctic Front Advance PRO™ system.

A 57-year-old patient with a history of aortic and mitral mechanical valve replacement was admitted with recurrent implantable cardioverter device shocks and antitachycardia pacing therapies. On electrocardiogram, the clinical ventricular tachycardia (VT) was compatible with an antero-lateral peri-mitral basal exit. Because of the inability to access the left ventricle through a percutaneous approach, epicardial VT ablation was performed. The VT and a second VT, consistently induced and coming from the left ventricular apex, were successfully treated with epicardial cryoablation via median sternotomy under cardiopulmonary bypass.

BACKGROUND: Inappropriate sinus tachycardia (IST) is defined as resting heart rate >100 beats/min and average 24-hour heart rate >90 beats/min. It is associated with distressing symptoms and significant loss of quality of life. Drugs are not effective in symptom control of IST in up to 30% of patients. Catheter ablation of the sinus node has a high recurrence rate, and the complications are significant. Recently, a novel hybrid sinus node-sparing ablation approach for IST was described. OBJECTIVE: The objective of the Hybrid Epicardial and Endocardial Sinus Node Sparing Ablation Therapy for Inappropriate Sinus Tachycardia (HEAL-IST) investigational device exemption trial (NCT05280093) is to evaluate safety and effectiveness of the hybrid sinus node-sparing ablation procedure for the treatment of symptomatic, drug-refractory or drug-intolerant IST. METHODS: The HEAL-IST trial is a prospective, multicenter, pivotal, single-arm trial. Up to 142 subjects in up to 40 centers will be treated in the trial with a Bayesian adaptive design. RESULTS: Subjects will be assessed for primary safety through 30 days post-hybrid ablation procedure. The primary effectiveness endpoint will be freedom from IST at 12 months. Freedom from IST will be defined as mean heart rate of ≤90 beats/min or at least a 15% reduction in mean heart rate as compared with baseline, in the absence of new or higher dosage of previously failed medications at a 24-month follow-up assessment. CONCLUSION: The HEAL-IST trial is the first multicenter trial evaluating hybrid IST ablation in patients with symptomatic IST and refractory or intolerant to drugs. The results of this study will help guide decision making regarding the best management in this population.

Aims Many clinical decision support systems trigger warning alerts for drug-drug interactions potentially leading to QT prolongation and torsades de pointes (QT-DDIs). Unfortunately, there is overalerting and underalerting because stratification is only based on a fixed QT-DDI severity level. We aimed to improve QT-DDI alerting by developing and validating a risk prediction model considering patient- and drug-related factors. Methods We fitted 31 predictor candidates to a stepwise linear regression for 1000 bootstrap samples and selected the predictors present in 95% of the 1000 models. A final linear regression model with those variables was fitted on the original development sample (350 QT-DDIs). This model was validated on an external dataset (143 QT-DDIs). Both true QTc and predicted QTc were stratified into three risk levels (low, moderate and high). Stratification of QT-DDIs could be appropriate (predicted risk = true risk), acceptable (one risk level difference) or inappropriate (two risk levels difference). Results The final model included 11 predictors with the three most important being use of antiarrhythmics, age and baseline QTc. Comparing current practice to the prediction model, appropriate stratification increased significantly from 37% to 54% appropriate QT-DDIs (increase of 17.5% on average [95% CI +5.4% to +29.6%], padj = 0.006) and inappropriate stratification decreased significantly from 13% to 1% inappropriate QT-DDIs (decrease of 11.2% on average [95% CI −17.7% to −4.7%], padj ≤ 0.001). Conclusion The prediction model including patient- and drug-related factors outperformed QT alerting based on QT-DDI severity alone and therefore is a promising strategy to improve DDI alerting.

Background: The lack of thermally and mechanically performant biomaterials represents the major limit for 3D-printed surgical guides, aimed at facilitating complex surgery and ablations. Methods: Cryosurgery is a treatment for cardiac arrhythmias. It consists of obtaining cryolesions, by freezing the target tissue, resulting in selective and irreversible damage. MED625FLX and TPU95A are two biocompatible materials for surgical guides; however, there are no data on their response to cryoenergy delivery. The study purpose is to evaluate the biomaterials' thermal properties, examining the temperature changes on the porcine muscle samples (PMS) when the biomaterials are in place during the cryoablation. Two biomaterials were selected, MED625FLX and TPU95A, with two thicknesses (1.0 and 2.5 mm). To analyze the biomaterials' behavior, the PMS temperatures were measured during cryoablation, firstly without biomaterials (control) and after with the biomaterials in place. To verify the biomaterials' suitability, the temperatures under the biomaterial samples should not exceed a limit of -30.0 °C. Furthermore, the biomaterials' geometry after cryoablation was evaluated using the grid paper test. Results: TPU95A (1.0 and 2.5 mm) successfully passed all tests, making this material suitable for cryoablation treatment. MED625FLX of 1.0 mm did not retain its shape, losing its function according to the grid paper test. Further, MED625FLX of 2.5 mm is also suitable for use with a cryoenergy source. Conclusions: TPU95A (1.0 and 2.5 mm) and MED625FLX of 2.5 mm could be used in the design of surgical guides for cryoablation treatment, because of their mechanical, geometrical, and thermal properties. The positive results from the thermal tests on these materials and their thickness prompt further clinical investigation. ispartof: JOURNAL OF CLINICAL MEDICINE vol:12 issue:3 ispartof: location:Switzerland status: published

Purpose: Drug-induced type I Brugada syndrome (BrS) is associated with a ventricular arrhythmia (VA) rate of 1 case per 100 person-years. This study aims to evaluate changes in electrocardiographic (ECG) parameters such as microvolt T wave alternans (mTWA) and heart rate variability (HRV) at baseline and during ajmaline testing for BrS diagnosis. Methods: Consecutive patients diagnosed with BrS during ajmaline testing with 5-year follow-up were included in this study. For comparison, a negative ajmaline control group and an isoproterenol control group were also included. ECG recordings during ajmaline or isoproterenol test were divided in two timeframes from which ECG parameters were calculated: a 5-min baseline timeframe and a 5-min drug timeframe. Results: A total of 308 patients with BrS were included, 22 (0.7%) of which suffered VAs during follow-up. One hundred patients were included in both isoproterenol and negative ajmaline control groups. At baseline, there was no difference in ECG parameters betweencontrol groups and patients with BrS, nor between BrS with and without VAs. During ajmaline testing, BrS with VAs presented longer QRS duration [159 ± 34 ms versus 138 (122–155) ms, p = 0.006], higher maximum mTWA [33.8 (14.0–114) µV versus 8.00 (3.67–28.2) µV, p = 0.001], and lower power in low frequency band [25.6 (5.8–53.8) ms 2 versus 129.5 (52.7–286) ms 2, p < 0.0001] when compared to BrS without VAs. Conclusions: Ajmaline induced important HRV changes similar to those observed during isoproterenol. Increased mTWA was observed only in patients with BrS. BrS with VAs during follow-up presented worse changes during ajmaline test, including lower LF power and higher maximum mTWA which were independent predictors of events.

Ventricular arrhythmias still represent an important cause of morbidity and mortality, especially in patients with heart failure and reduced left ventricular ejection fraction. Amiodarone is a Class III Vaughan-Williams anti-arrhythmic drug widely used in ventricular arrhythmias for its efficacy and low pro-arrhythmogenic effect. On the other hand, a significant limitation in its use is represented by toxicity. In this review, the pharmacology of the drug is discussed to provide the mechanistic basis for its clinical use. Moreover, all the latest evidence on its role in different clinical settings is provided, including the prevention of sudden cardiac death, implanted cardioverter defibrillators, ischemic and non-ischemic cardiomyopathies. A special focus is placed on everyday clinical practice learning points, such as dosage, indications, and contraindications from the latest guidelines.

Background: In the field of medicine, photogrammetry has played for long time a marginal role due to the significant amount of work required that made it impractical for an extended medical use. Developments in digital photogrammetry occurred in the recent years, that have steadily increased the interest and application of this technique. The present study aims to compare photogrammetry reconstruction of heart with computed tomography (CT) as a reference.Methods: The photogrammetric reconstructions of digital images from ECG imaging derived images were performed. In particular, the ventricles of 15 patients with Brugada syndrome were reconstructed by using the free Zephyr Lite software. In order to evaluate the accuracy of the technique, measurements on the reconstructions were compared to patient-specific CT scan imported in ECG imaging software UZBCIT.Result: The results showed that digital photogrammetry in the context of ventricle reconstruction is feasible. The photogrammetric derived measurements of ventricles were not statistically different from CT scan measurements. Furthermore, the analysis showed high correlation of photogrammetry reconstructions with CT scan and a correlation coefficient close to 1.Conclusion: It is possible to reproduce digital objects by photogrammetry if the process described in this study is performed. The reconstruction of the ventricles from CT scan was very close to the values of the respective photogrammetric reconstruction.

Introduction Atrial fibrillation (AF) is the most common sustained arrhythmia and an important risk factor for stroke and heart. Recent technology advances have allowed for heart rhythm monitoring using smart gadgets/wearable devices which can be used for early AF diagnosis. Hypothesis We performed a systemic review and meta-analysis to assess the accuracy of AF diagnosis by smart gadgets/wearable devices. Methods We systematically searched Medline, Embase and Cochrane electronic databases up to April 15th, 2022 for observational studies of the diagnostic accuracy of smartphone application, wrist-worn wearables and external devices in detecting AF. We calculated the area under the curve (AUC) of the summary receiver operating characteristic curves (SROC) and pooled sensitivities and specificities. Results A total of 79 studies were included enrolling 36903 patients, 66.3% male with average age of 68.3±8 years. In the overall analysis of all devices, the AUC was 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(95% CI: 94–96%), the specificity 96%(95% CI: 96–97%). Wrist-worn wearables had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(9% CI: 92–97%), the specificity 97%(95% CI: 96–98%)(Figure 1A). Smartphone applications had AUC of 0.98 (95% CI: 0.96-0.99), the sensitivity 96%(9% CI: 94–97%), the specificity 96%(95% CI: 93–98%)(Figure 1B). External devices had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(9% CI: 93–97%), the specificity 96%(95% CI: 95–97%)(Figure 1C). Single-lead ECG had AUC of 0.99 (95% CI: 0.98- 1.00), the sensitivity 95%(9% CI: 92–96%), the specificity 96%(95% CI: 95–97%). PPG had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 96%(9% CI: 95–97%), the specificity 97%(95% CI: 95–98%). Conclusions Smartphone application, wrist-worn devices and external devices with PPG and single-lead ECG have excellent diagnostic accuracy in atrial fibrillation diagnosis. Figure 1. Summary Receiver Operating Characteristic curves and Areas Under The Curve of Wrist-worn wearables (A), Smartphone applications (B) and External devices (C).

Background Atrial fibrillation (AF) and heart failure (HF) often coexist and syner-gistically contribute to an increased risk of hospitalization, stroke, and mortality. Objective: To compare the efficacy of catheter ablation (CA) versus medical therapy (MT) in HF patients with AF. Methods Electronic databases were queried for randomized controlled trials (RCTs) of CA versus MT of AF in patients with HF. Risk ratios (RRs), mean differences (MDs), and 95% confidence in-tervals (CIs) were measured using the Mantel–Haenszel method. Results A total of nine RCTs enrolling 2155 patients met the inclusion criteria. Compared to MT, CA led to a significant reduction in the composite of all-cause mortality and HF hospitalization (24.6% vs. 37.1%; RR: 0.65 (95% CI: 0.53–0.80); p < 0.0001) (Figure 1), all-cause mortality (8.8% vs. 13.6%; RR: 0.65 (95% CI: 0.51–0.82); p = 0.0005), HF hospitalization (15.4% vs. 22.4%; (RR: 0.67 (95% CI: 0.54–0.82); p = 0.0001), AF re-currence (31.8% vs. 77.0%; RR: 0.36 (95% CI: 0.24–0.54); p < 0.0001), and cardiovascular (CV) death (4.9% vs. 8.4%; RR: 0.58 (95% CI: 0.39–0.86); p = 0.007). CA improved the left ventricular ejection fraction (MD:4.76% (95% CI: 2.35–7.18); p = 0.0001), 6 min walk test (MD: 20.48 m (95% CI: 10.83–30.14); p < 0.0001), peak oxygen consumption (MD: 3.1 2mL/kg/min (95% CI: 1.01–5.22); p = 0.004), Minnesota Living with Heart Failure Questionnaire score (MD: −6.98 (95% CI: −12–03, −1.93); p = 0.007), and brain natriuretic peptide levels (MD:−133.94 pg/mL (95% CI: −197.33, −70.55); p < 0.0001). Conclusions In HF patients, AF catheter ablation was superior to MT in re-ducing CV and all-cause mortality. Further significant benefits occurred within the ablation group in terms of HF hospitalizations, AF recurrences, the systolic function, exercise capacity, and quality of life. Figure 1: Forest plot displaying a decrease in the composite endpoint in patients with AF and HF undergoing CA versus MT.

Introduction Atrial fibrillation (AF) is the most common sustained arrhythmia and an important risk factor for stroke and heart. Recent technology advances have allowed for heart rhythm monitoring using smart gadgets/wearable devices which can be used for early AF diagnosis. Hypothesis We performed a systemic review and meta-analysis to assess the accuracy of AF diagnosis by smart gadgets/wearable devices. Methods We systematically searched Medline, Embase and Cochrane electronic databases up to April 15th, 2022 for observational studies of the diagnostic accuracy of smartphone application, wrist-worn wearables and external devices in detecting AF. We calculated the area under the curve (AUC) of the summary receiver operating characteristic curves (SROC) and pooled sensitivities and specificities. Results A total of 79 studies were included enrolling 36903 patients, 66.3% male with average age of 68.3±8 years. In the overall analysis of all devices, the AUC was 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(95% CI: 94–96%), the specificity 96%(95% CI: 96–97%). Wrist-worn wearables had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(9% CI: 92–97%), the specificity 97%(95% CI: 96–98%)(Figure 1A). Smartphone applications had AUC of 0.98 (95% CI: 0.96-0.99), the sensitivity 96%(9% CI: 94–97%), the specificity 96%(95% CI: 93–98%)(Figure 1B). External devices had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 95%(9% CI: 93–97%), the specificity 96%(95% CI: 95–97%)(Figure 1C). Single-lead ECG had AUC of 0.99 (95% CI: 0.98- 1.00), the sensitivity 95%(9% CI: 92–96%), the specificity 96%(95% CI: 95–97%). PPG had AUC of 0.99 (95% CI: 0.98-1.00), the sensitivity 96%(9% CI: 95–97%), the specificity 97%(95% CI: 95–98%). Conclusions Smartphone application, wrist-worn devices and external devices with PPG and single-lead ECG have excellent diagnostic accuracy in atrial fibrillation diagnosis. Figure 1. Summary Receiver Operating Characteristic curves and Areas Under The Curve of Wrist-worn wearables (A), Smartphone applications (B) and External devices (C).

BACKGROUND: This study aimed to evaluate the feasibility and safety of an innovative "all in one" integrated transseptal crossing device to achieve transseptal puncture (TSP). METHODS: Twenty patients (10 males, mean age 65.65 ± 9.25 years), indicated to supraventricular left side tachyarrhythmia ablation, underwent TSP using a new-generation integrated crossing device, and a control cohort of twenty patients (10 males, mean age 65.5 ± 10.12 years) underwent TSP using the traditional TSP system. RESULTS: In all the study patients, the novel TSP device led to a successful and safe access to the left atrium (LA). The mean transseptal time, defined as the time occurring between the groin puncture and the advancing of the guidewire into the left superior pulmonary vein (PV), was 3 min 33 s ± 44 s, 7 min 5 s ± 36 s in the control cohort. Additionally, we compared the cost of the two systems. No acute complications related to the TSP were noted in both cohorts. CONCLUSIONS: TSP performed with the new integrated transseptal system is feasible and safe.

Background3D printing technology development in medical fields allows to create 3D models to assist preoperative planning and support surgical procedures. Cardiac ischemic scar is clinically associated with malignant arrhythmias. Catheter ablation is aimed at eliminating the arrhythmogenic tissue until the sinus rhythm is restored. The scope of this work is to describe the workflow for a 3D surgical guide able to define the ischemic scar and target catheter ablation.Materials and methodsFor the patient-specific 3D surgical guide and 3D heart phantom model realization, both CT scan and cardiac MRI images were processed; this was necessary to extract anatomical structures and pathological information, respectively. Medical images were uploaded and processed in 3D Slicer. For the surgical guide modeling, images from CT scan and MRI were loaded in Meshmixer and merged. For the heart phantom realization, only the CT segmentation was loaded in Meshmixer. The surgical guide was printed in MED625FLX with Polyjet technology. The heart phantom was printed in polylactide with FDM technology.Results3D-printed surgical model was in agreement with prespecified imputed measurements. The phantom fitting test showed high accuracy of the 3D surgical tool compared with the patient-specific reproduced heart. Anatomical references in the surgical guide ensured good stability. Ablation catheter fitting test showed high suitability of the guide for different ablation tools.ConclusionA 3D-printed guide for ventricular tachycardia ablation is feasible and accurate in terms of measurements, stability, and geometrical structure. Concerning clinical use, further clinical investigations are eagerly awaited.

Management of ventricular arrhythmias (VAs) beyond implantable cardioverter-defibrillator positioning in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is challenging. Catheter ablation of the ventricular substrate often requires a combination of endocardial and epicardial approaches, with disappointing outcomes due to the progressive nature of the disease. We report the Universitair Ziekenhuis Brussel experience through a case series of 16 patients with drug-refractory ARVC, who have undergone endocardial and/or epicardial catheter ablation of VAs with a thoracoscopic hybrid-approach. After a mean follow-up time of 5.16 years (SD 2.9 years) from the first hybrid-approach ablation, VA recurrence was observed in 5 patients (31.25%): among these, patients 4 patients (80%) received a previous ablation and 1 of 11 patients (9.09%) who had a hybrid ablation as first approach had a VA recurrence (80% vs 9.09%; log-rank p = 0.04). Despite the recurrence rate of arrhythmic events, all patients had a significant reduction in the arrhythmic burden after ablation, with a mean of 4.65 years (SD 2.9 years) of freedom from clinically significant arrhythmias, defined as symptomatic VAs or implantable cardioverter-defibrillator-delivered therapies. In conclusion, our case series confirms that management of VAs in patients with ARVC is difficult because patients do not always respond to antiarrhythmic medications and can require multiple invasive procedures. A multidisciplinary approach involving cardiologists, cardiac surgeons, and cardiac electrophysiologists, together with recent cardiac mapping techniques and ablation tools, might mitigate these difficulties and improve outcomes.

Myotonia congenita is a rare neuromuscular disorder caused by CLCN1 mutations resulting in delayed muscle relaxation. Extramuscular manifestations are not considered to be present in chloride skeletal channelopathies, although recently some cardiac manifestations have been described. We report a family with autosomal dominant myotonia congenita and Brugada syndrome. Bearing in mind the previously reported cases of cardiac arrhythmias in myotonia congenita patients, we discuss the possible involvement of the CLCN1-gene mutations in primary cardiac arrhythmia.

Background: Atrial fibrillation (AF) and heart failure (HF) often coexist and synergistically contribute to an increased risk of hospitalization, stroke, and mortality. Objective: To compare the efficacy of catheter ablation (CA) versus medical therapy (MT) in HF patients with AF. Methods: Electronic databases were queried for randomized controlled trials (RCTs) of CA versus MT of AF in patients with HF. Risk ratios (RRs), mean differences (MDs), and 95% confidence intervals (CIs) were measured using the Mantel–Haenszel method. Results: A total of nine RCTs enrolling 2155 patients met the inclusion criteria. Compared to MT, CA led to a significant reduction in the composite of all-cause mortality and HF hospitalization (24.6% vs. 37.1%; RR: 0.65 (95% CI: 0.53–0.80); p < 0.0001), all-cause mortality (8.8% vs. 13.6%; RR: 0.65 (95% CI: 0.51–0.82); p = 0.0005), HF hospitalization (15.4% vs. 22.4%; (RR: 0.67 (95% CI: 0.54–0.82); p = 0.0001), AF recurrence (31.8% vs. 77.0%; RR: 0.36 (95% CI: 0.24–0.54); p < 0.0001), and cardiovascular (CV) death (4.9% vs. 8.4%; RR: 0.58 (95% CI: 0.39–0.86); p = 0.007). CA improved the left ventricular ejection fraction (MD:4.76% (95% CI: 2.35–7.18); p = 0.0001), 6 min walk test (MD: 20.48 m (95% CI: 10.83–30.14); p < 0.0001), peak oxygen consumption (MD: 3.1 2mL/kg/min (95% CI: 1.01–5.22); p = 0.004), Minnesota Living with Heart Failure Questionnaire score (MD: −6.98 (95% CI: −12–03, −1.93); p = 0.007), and brain natriuretic peptide levels (MD:−133.94 pg/mL (95% CI: −197.33, −70.55); p < 0.0001). Conclusions: In HF patients, AF catheter ablation was superior to MT in reducing CV and all-cause mortality. Further significant benefits occurred within the ablation group in terms of HF hospitalizations, AF recurrences, the systolic function, exercise capacity, and quality of life.

We performed an electrocardiographic imaging (ECGi) study during the hybrid-approach ablation of a 50-year-old man affected by arrhythmogenic right ventricular cardiomyopathy (ARVC), with documented ventricular tachycardia (VT) and intolerance to anti-arrhythmic drugs. In this patient, the VT induction protocol during the hybrid procedure induced monomorphic VT having the same characteristics of the clinical VT. We used the ECGi to compare the electrophysiological properties of the myocardium of this ARVC patient (voltage map in sinus rhythm and activation map during the VT) with the abnormal electrograms (aEGMs) detected with the contact mapping, target for the substrate ablation. The spatial correlation between the ECGi and the epicardial contact mapping led to the identification of the arrhythmogenic substrate; ablation of the identified areas was then performed. Re-mapping after ablation documented disappearance of aEGMs. The same induction protocol was repeated, but VT was no longer inducible. An implantable cardioverter defibrillator was implanted at the end of the procedure.

BackgroundDue to their mechanical properties, the MED625FLX and TPU95A could be appropriate candidates for cardiac 3D surgical guide use during radiofrequency ablation (RFA) treatment.MethodsRFA aims to destroy the heart tissue, which cause arrhythmias, by applying a radiofrequency (RF) energy at critical temperature above +50.0°C, where the thermal damage is considered not reversible. This study aims to analyze the biomaterials thermal properties with different thicknesses, by testing the response to bipolar and unipolar RFA on porcine muscle samples (PMS), expressed in temperature. For the materials evaluation, the tissue temperature during RFA applications was recorded, firstly without (control) and after with the biomaterials in position. The biomaterials were considered suitable for the RFA treatment if: (1) the PMS temperatures with the samples were not statistically different compared with the control; (2) the temperatures never reached the threshold; (3) no geometrical changes after RFA were observed.ResultsBased on these criteria, none of the tested biomaterials resulted appropriate for unipolar RFA and the TPU95A failed almost all thermal tests also with the bipolar RFA. The 1.0 mm MED625FLX was modified by bipolar RFA in shape, losing its function. Instead, the 2.5 mm MED625FLX was considered suitable for bipolar RFA catheter use only.ConclusionsThe 2.5 mm MED625FLX could be used, in the design of surgical guides for RFA bipolar catheter only, because of mechanical, geometrical, and thermal properties. None of biomaterials tested are appropriate for unipolar ablation catheter because of temperature concerns. Further investigations for clinical use are eagerly awaited.

Electrical isolation of pulmonary veins (PVI) is the cornerstone of invasive treatment of atrial fibrillation (AF). However, arrhythmia-free survival of a PVI only approach is suboptimal in patients with persistent and long-term persistent AF. Hybrid AF ablation has been developed with the aim of combining the advantages of a thoracoscopic surgical ablation (direct visualization of anatomical structures to be spared and the possibility to perform epicardial lesions) and endocardial ablation (possibility to check line block, confirm PVI, and possibility to perform cavotricuspid isthmus ablation). Patient selection is of utmost importance. In persistent and long-term persistent AF, hybrid AF ablation demonstrated promising results in terms of AF free survival. It has been associated with a relatively low complication rate if performed in centers with expertise in hybrid procedures and experience with both surgical and endocardial ablation. Different techniques have been described, with different approaches and lesion sets. The aim of this review is to provide a state-of-the-art overview of hybrid AF ablation.

BackgroundLeft atrial appendage (LAA) is a common source of thrombi in patients with atrial fibrillation (AF). The effect on left atrial (LA) function of the Totally Thoracoscopic (TT)-LAA exclusion with epicardial clip is currently unknown. This study aims at evaluating the effect of TT-LAA exclusion on LA function.MethodsStandalone TT-LAA exclusion with the clip device was performed in 26 patients with AF and contraindication to oral anticoagulation (OAC). A 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound were performed preoperatively. Clip positioning and LAA exclusion were guided and confirmed by intraoperative trans-esophageal echo. To evaluate LA function, standard transthoracic echocardiography and 2D strain of LA were performed before surgery, at discharge and at 3-month follow-up.ResultsThe mean CHA2DS2-VASc and HASBLED scores were 4.6 and 2.4 respectively. There were no major complications during the procedure. At median follow-up of 10.3 months, 1 (3.8%) non-cardiovascular death, 1 (3.8%) stroke and 4 (15.4%) cardiovascular hospitalizations occurred. At 2D strain of LA, the reservoir function decreased significantly at discharge, compared to baseline and recovered at 3-months follow-up. Furthermore, NT-proBNP increased significantly after the procedure with a return to baseline after 3 months. Changes in E/A were persistent at 3 months.ConclusionOur data in a small cohort suggest that TT-LAA exclusion with epicardial clip can be a safe procedure with regards to the atrial function. The LAA amputation impairs the reservoir LA function on the short term, that recovers over time.

BackgroundBrugada syndrome (BrS) is a disease associated with ventricular arrhythmias and sudden cardiac death. Epicardial ablation has demonstrated high therapeutic efficacy in preventing ventricular arrhythmias. The purpose of this research is to define a workflow to create a patient-specific 3D-printed tool to be used as a surgical guide for epicardial ablation in BrS.MethodsDue to their mechanical properties and biocompatibility, the MED625FLX and TPU95A were used for cardiac 3D surgical guide printing. ECG imaging was used to define the target region on the right ventricular outflow tract (RVOT). CT scan imaging was used to design the model based on patient anatomy. A 3D patient-specific heart phantom was also printed for fitting test. Sterilization test was finally performed.Results3D printed surgical models with both TPU95A and MED625FLX models were in agreement with pre-specified imputed measurements. The phantom test showed retention of shape and correct fitting of the surgical tool to the reproduced phantom anatomy, as expected, for both materials. The surgical guide adapted to both the RVOT and the left anterior descending artery. Two of the 3D models produced in MED265FLX showed damage due to the sterilization process.ConclusionsA 3D printed patient-specific surgical guide for epicardial substrate ablation in BrS is feasible if a specific workflow is followed. The design of the 3D surgical guide ensures proper fitting on the heart phantom with good stability. Further investigations for clinical use are eagerly awaited.

It is unclear whether the association between atrial fibrillation (AF) and intra-hospital mortality in patients aged 75 years and older is causal or not. This study aims (1) to describe the prevalence and clinical characteristics of AF in ≥75-year-old inpatients and (2) to study the association between AF and length of stay (LOS) and intra-hospital mortality. This retrospective cohort study includes consecutive patients aged ≥75 years admitted between January 2017 and December 2019 to a Belgian secondary hospital. Survival analysis was conducted on the whole dataset and a propensity score-matched dataset separately. Propensity score matching (PSM) was performed to account for the individual probability of having AF given a set of covariates. In 9,105 patients, 3,137 (34%) had a diagnosis of AF upon hospital admission. AF prevalence increased with age strata (from 29% to 38%), and Charlson Co-morbidity Index (from 28% to 57%). Intra-hospital mortality (20%) was higher in the AF group than in the AF-free group (25% vs 17%, p 10 days (odds ratio 1.08, confidence interval: 0.98 to 1.20, p = 0.13). The risk of intra-hospital death for patients with AF remained higher compared with those without AF (log-rank p = 0.0015 and hazard ratio 1.17; confidence interval: 1.04 to 1.32, p = 0.008). In conclusion, the prevalence of AF was high (34%) in inpatients aged ≥75 years and increased with age and co-morbidity burden. After PSM, patients with AF had a 17% higher risk of intra-hospital mortality than patients without AF.

Background Pharmacological treatment of atrial fibrillation (AF) in the setting of Brugada syndrome (BrS) is challenging. In addition, patients with BrS with an implantable cardioverter‐defibrillator (ICD) might experience inappropriate shocks for fast AF. Long‐term outcome of pulmonary vein isolation in BrS has not been well established yet, and it is still unclear whether pulmonary vein triggers are the only pathophysiological mechanism of AF in BrS. The aim of the study is to assess the long‐term outcomes in patients with BrS undergoing pulmonary vein isolation for paroxysmal AF compared with a matched cohort of patients without BrS. Methods and Results Sixty patients with BrS undergoing pulmonary vein isolation with cryoballoon catheter ablation for paroxysmal AF were matched with 60 patients without BrS, who underwent the same procedure. After a mean follow‐up of 58.2±31.7 months, freedom from atrial tachyarrhythmias was achieved in 61.7% in the BrS group and in 78.3% in the non‐BrS group (log‐rank P =0.047). In particular, freedom from AF was 76.7% in the first group and in 83.3% in the second ( P =0.27), while freedom from atrial tachycardia/atrial flutter was 85% and 95% ( P =0.057). In the BrS group, 29 patients (48.3%) had an ICD and 8 (27.6%) had a previous ICD‐inappropriate shock for fast AF. In the BrS cohort, ICD‐inappropriate interventions for AF were significantly reduced after ablation (3.4% versus 27.6%; P =0.01). Conclusions Pulmonary vein isolation in patients with BrS was associated with higher rate of arrhythmic recurrence. Despite this, catheter ablation significantly reduced inappropriate ICD interventions in BrS patients and can be considered a therapeutic strategy to prevent inappropriate device therapies.

PURPOSE: Pulmonary vein isolation (PVI) with radiofrequency (RF) catheter ablation is an effective treatment option for patients with paroxysmal AF. However, traditional point by point RF ablation can be time consuming and technically challenging. To simplify the ablation procedure, without compromising procedure outcome, several "single shot" ablation systems have been developed. The multi-electrode RF Balloon catheter HELIOSTAR is a 28-mm compliant balloon compatible with the CARTO 3D electroanatomical mapping system; an optimized step-by-step workflow to perform PVI is described. METHODS: Procedures are performed under general anesthesia with unique transseptal puncture. To evaluate the optimal electrode-tissue contact and best RF Balloon positioning, the following baseline indicators should be fulfilled: inflation index > 0.8, impedance range close to 100 Ohms with a variability of less than 20 Ohms across electrodes, temperature variability on all electrodes 2 °C compared to baseline) and 60 s for all the other segments. Target parameters for PVI are 1) time to isolation less than 12 s; 2) impedance drop > 12 Ohms; 3) temperature rise > 6 °C. CONCLUSIONS: Standardized workflow for RF Balloon is mandatory to achieve efficacy and safety with this new promising technology. In the absence of international guidelines, a single high-volume center procedural strategy is described for PVI.

INTRODUCTION: Catheter ablation has been demonstrated to be a safe and an effective treatment for drug resistant atrial fibrillation (AF); electrical isolation of pulmonary veins (PVI) is the main strategy in paroxysmal AF, since pulmonary vein triggers have a pivotal role in its pathogenesis; non-paroxysmal AF is a complex arrhythmia that results from the interplay of a substrate, namely AF-induced electrical and structural atrial remodeling, and a trigger that can be often found outside pulmonary veins, namely non-pulmonary veins triggers. AREAS COVERED: The aim of this review is to provide a state-of-the-art overview of non-pulmonary veins triggers with special focus on cryoballoon (CB) catheter ablation. EXPERT OPINION: Besides PVI, CB catheter ablation of non-pulmonary veins triggers is a novel and promising strategy for non-paroxysmal AF.

BackgroundNew technologies for ablation procedures are often produced by different companies with no cross-compatibility out of the box. This is not a negligible clinical problem since those separately developed devices are often used together. The aim of this study was to develop a bench-testing method to assess compatibility between the DiamondTemp ablation system (DTA) and the Rhythmia electroanatomic mapping system (EAM).MethodsDifferent setups were tested. DTA was connected to the Rhythmia EAM using the following configurations: 3.1. An Ensite EPT GenConnect box (GCB) and Rhythmia Maestro GCB (Maestro GCB, native Rhythmia setup); 3.2. The Medtronic GCB-E and Maestro GCB; 3.3. The Medtronic GCB-E out via the Medtronic GCB-E directly to the Rhythmia at box 1 (pin A61 to A64).ResultsThe DTA location was represented in real-time on the Rhythmia EAM. A proper tracking of the DTA was observed in all setups tested by visual comparison of physical catheter movements and its representation on EAM. In configuration 3.1, a significant shift was observed after the first radio frequency (RF) application; however, further applications caused no further shift. In setup 3.2, no significant shift was observed. The setup 3.3 showed a massive shift in the catheter position before ablation compared to baseline points acquired using the Orion catheter as a reference.ConclusionsA universal and reproducible solution for compatibility testing between the various mapping systems and the ablation catheters has been described. DTA has been demonstrated as compatible with Rhythmia EAM with satisfactory results if a specific setup is used.

BACKGROUND: Cryoballoon technology (CB-A) has become a cornerstone of atrial fibrillation (AF) ablation in terms of safety and efficacy. Data regarding CB-A in octogenarians are still scarce and limited to single center experiences. The present study sought to analyze the performances of index CB-A in patients older than 80 years-old referring to 3 high-volume European centers. METHODS AND RESULTS: We retrospectively enrolled 95 patients with a median age of 81 [80, 83] years. 62 (65.3%) patients presented with paroxysmal AF and 33 (33.7%) with persistent AF. Mean procedure and fluoroscopy times were 73.8 ± 25.2 and 15.3 ± 7.5 min, respectively. At 12 months and 24 months of follow-up, the overall freedom from AF was 81.1% and 66.6%, respectively. When divided for AF type, freedom from AF was higher in patients with paroxysmal AF (p = 0.007). Cryoballoon ablation was able to significantly improve AF-related symptoms as proven by the significant decrease in EHRA score during the follow-up (p

The purpose of this review is to determine the causal mechanisms and treatment of inappropriate sinoatrial tachycardia (IST), defined as a non-physiological elevation in resting heart rate. IST is defined as a resting daytime sinus rate >100 beats/minute and an average 24-hour heart rate >90 beats/minute. Potential causal mechanisms include sympathetic receptor hypersensitivity, blunted parasympathetic tone, or enhanced intrinsic automaticity within the sinoatrial node (SAN) pacemaker-conduction complex. These anomalies may coexist in the same patient. Recent ex-vivo near-infrared transmural optical imaging of the SAN in human and animal hearts provides important insights into the functional and molecular features of this complex structure. In particular, it reveals the existence of preferential sinoatrial conduction pathways that ensure robust SAN activation with electrical conduction. The mechanism of IST is debated because even high-resolution electroanatomical mapping approaches cannot reveal intramural conduction in the 3-dimensional SAN complex. It may be secondary to enhanced automaticity, intranodal re-entry, or sinoatrial conduction pathway re-entry. Different pharmacological approaches can target these mechanisms. Long-acting β blockers in IST can act on both primarily increased automaticity and dysregulated autonomic system. Ivabradine targets sources of increased SAN automaticity. Conventional or hybrid ablation may target all the described abnormalities. This review provides a state-of-the-art overview of putative IST mechanisms. In conclusion, based on current knowledge, pharmacological and ablation approaches for IST, including the novel hybrid SAN sparing ablation, are discussed.

Patient-specific three-dimensional (3D) printed models have been increasingly used in many medical fields, including cardiac surgery for which they are used as planning and communication tools. To locate and plan the correct region of interest for the bypass placement during coronary artery bypass graft (CABG) surgery, cardiac surgeons can pre-operatively rely on different medical images. This article aims to present a workflow for the production of a patient-specific 3D-printed surgical guide, from data acquisition and image segmentation to final prototyping. The aim of this surgical guide is to help visualize the region of interest for bypass placement during the operation, through the use of dedicated surgical holes. The results showed the feasibility of this surgical guide in terms of design and fitting to the phantom. Further studies are needed to assess material biocompatibility and technical properties. ispartof: BIOENGINEERING-BASEL vol:9 issue:5 ispartof: location:Switzerland status: published

Background The rate of sudden cardiac death (SCD) in Brugada syndrome (BrS) is ≈1%/y. Noninvasive electrocardiographic imaging is a noninvasive mapping system that has a role in assessing BrS depolarization and repolarization abnormalities. This study aimed to analyze electrocardiographic imaging parameters during ajmaline test (AJT). Methods and Results All consecutive epicardial maps of the right ventricle outflow tract (RVOT‐EPI) in BrS with CardioInsight were retrospectively analyzed. (1) RVOT‐EPI activation time (RVOT‐AT); (2) RVOT‐EPI recovery time, and (3) RVOT‐EPI activation‐recovery interval (RVOT‐ARI) were calculated. ∆RVOT‐AT, ∆RVOT‐EPI recovery time, and ∆RVOT‐ARI were defined as the difference in parameters before and after AJT. SCD‐BrS patients were defined as individuals presenting a history of aborted SCD. Thirty‐nine patients with BrS were retrospectively analyzed and 12 patients (30.8%) were SCD‐BrS. After AJT, an increase in both RVOT‐AT [105.9 milliseconds versus 65.8 milliseconds, P P P =0.7]. Before AJT no differences were observed between SCD‐BrS and non SCD‐BrS in RVOT‐AT, RVOT‐EPI recovery time, and RVOT‐ARI ( P =0.9, P =0.91, P =0.86, respectively). Following AJT, SCD‐BrS patients showed higher RVOT‐AT, higher ∆RVOT‐AT, lower RVOT‐ARI, and lower ∆RVOT‐ARI ( P P P =0.007, P =0.002, respectively). At the univariate logistic regression, predictors of SCD‐BrS were the following: RVOT‐AT after AJT (specificity: 0.74, sensitivity 1.00, area under the curve 0.92); ∆RVOT‐AT (specificity: 0.74, sensitivity 0.92, area under the curve 0.86); RVOT‐ARI after AJT (specificity 0.96, sensitivity 0.58, area under the curve 0.79), and ∆RVOT‐ARI (specificity 0.85, sensitivity 0.67, area under the curve 0.76). Conclusions Noninvasive electrocardiographic imaging can be useful in evaluating the results of AJT in BrS.

IntroductionPredictors of late life-threatening arrhythmic events in Brugada syndrome (BrS) patients who received a prophylactic ICD implantation remain to be evaluated. The aim of the present long-term multicenter study was to assess the incidence and clinical-electrocardiographic predictors of late life-threatening arrhythmic events in BrS patients with a prophylactic implantable cardioverter defibrillator (ICD) and undergoing generator replacement (GR).MethodsThe study population included 105 patients (75% males; mean age 45 ± 14years) who received a prophylactic ICD and had no arrhythmic event up to first GR.ResultsThe median period from first ICD implantation to last follow-up was 155 (128–181) months and from first ICD Implantation to the GR was 84 (61–102) months. During a median follow-up of 57 (38–102) months after GR, 10 patients (9%) received successful appropriate ICD intervention (1.6%/year). ICD interventions included shock on ventricular fibrillation (n = 8 patients), shock on ventricular tachycardia (n = 1 patient), and antitachycardia pacing on ventricular tachycardia (n = 1 patient). At survival analysis, history of atrial fibrillation (log-rank test; P = 0.02), conduction disturbances (log-rank test; P < 0.01), S wave in lead I (log-rank test; P = 0.01) and first-degree atrioventricular block (log-rank test; P = 0.04) were significantly associated with the occurrence of late appropriate ICD intervention. At Cox-regression multivariate analysis, S-wave in lead I was the only independent predictor of late appropriate ICD intervention (HR: 9.17; 95%CI: 1.15–73.07; P = 0.03).ConclusionsThe present study indicates that BrS patient receiving a prophylactic ICD may experience late appropriate intervention after GR in a clinically relevant proportion of cases. S-wave in lead I at the time of first clinical evaluation was the only independent predictor of persistent risk of life-threatening arrhythmic events. These findings support the need for GR at the end of service regardless of previous appropriate intervention, mostly in BrS patients with conduction abnormalities.

[This corrects the article DOI: 10.3389/fcvm.2022.964694.].

BackgroundCoronavirus disease 2019 (COVID-19) is a systemic disease caused by severe acute respiratory syndrome coronavirus 2. Arrhythmias are frequently associated with COVID-19 and could be the result of inflammation or hypoxia. This study aimed to define the incidence of arrhythmias in patients with COVID-19 and to correlate arrhythmias with pulmonary damage assessed by computed tomography (CT).MethodsAll consecutive patients with a COVID-19 diagnosis hospitalized at Universitair Ziekenhuis Brussel, Belgium, between March 2020 and May 2020, were screened. All included patients underwent a thorax CT scan and a CT severity score, a semiquantitative scoring system of pulmonary damage, was calculated. The primary endpoint was the arrhythmia occurrence during follow-up.ResultsIn this study, 100 patients were prospectively included. At a mean follow-up of 19.6 months, 25 patients with COVID-19 (25%) experienced 26 arrhythmic episodes, including atrial fibrillation in 17 patients, inappropriate sinus tachycardia in 7 patients, atrial flutter in 1 patient, and third-degree atrioventricular block in 1 patient. No ventricular arrhythmias were documented. Patients with COVID-19 with arrhythmias showed more often need for oxygen, higher oxygen maximum flow, longer QTc at admission, and worse damage at CT severity score. In univariate logistic regression analysis, significant predictors of the primary endpoint were: the need for oxygen therapy (odds ratio [OR] 4.59, 95% CI 1.44–14.67, p = 0.01) and CT severity score of pulmonary damage (OR per 1 point increase 1.25, 95% CI 1.11–1.4, p < 0.001).ConclusionsIn a consecutive cohort of patients with COVID-19 the incidence of cardiac arrhythmias was 25%. The need for oxygen therapy and CT severity score were predictors of arrhythmia occurrence during follow-up.

Introduction 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 repeated 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 ablation with 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 ≥160ms2 associated with 3 times and 5 times higher odds of PVs reconnection, respectively. On a vein-per-vein analysis, absolute VLF power ≥160ms2 associated with 3 times higher odds, while reaching of -40°C within 60 seconds associated with 3 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. This article is protected by copyright. All rights reserved.

BACKGROUND: The pathogenesis of Brugada syndrome (BrS) and consequently of abnormal electrograms (aEGMs) found in the epicardium of the right ventricular outflow tract (RVOT-EPI) is controversial. OBJECTIVE: The purpose of this study was to analyze aEGM from high-density RVOT-EPI electroanatomic mapping (EAM). METHODS: All patients undergoing RVOT-EPI EAM with the HD-Grid catheter for BrS were retrospectively included. Maps were acquired before and after ajmaline, and all patients had concomitant noninvasive electrocardiographic imaging with annotation of RVOT-EPI latest activation time (RVOTat). High-frequency potentials (HFPs) were defined as ventricular potentials occurring during or after the far-field ventricular EGM showing a local activation time (HFPat). Low-frequency potentials (LFPs) were defined as aEGMs occurring after near-field ventricular activation showing fractionation or delayed components. Their activation time from surface ECG was defined as LFPat. RESULTS: Fifteen consecutive patients were included in the study. At EAM before ajmaline, 7 patients (46.7%) showed LFPs. All patients showed HFPs before and after ajmaline and LFPs after ajmaline. Mean HFPat (134.4 vs 65.3 ms, P

Background/Introduction Brugada syndrome (BrS) has been initially described as a channelopathy with no structural heart disease but a growing body of evidence points towards structural anomalies in the epicardium of right ventricle outflow tract (RVOT-EPI). Since its first description the electrical substrate of BrS has been thought to be a fractionation of the electrograms (EGMs) in the RVOT-EPI. Also there is recent evidence that SCN5A mutation BrS patients might be at increased risk of sudden cardiac death (SCD). No studies correlated high-density mapping substrate with clinical outcomes. Purpose The aim of the current study was to compare clinical characteristics of BRS patients with EGMs characteristics from high-density epicardial mapping with Advisor HD-Grid mapping catheter. Methods All consecutive patients with BrS who underwent hybrid RVOT-EPI substrate ablation at our University Hospital between April 2018 and March 2021 were retrospectively included in the study. Genetic analysis was performed in all patients and clinical data were collected. BrS was diagnosed following current recommendations. Inclusion criteria were: 1) use of Advisor HD-Grid mapping catheter and 3D-electroanatomical (EAM) mapping system EnSite Precision; 2) acquisition of EAM before and after ajmaline infusion at standard protocol (1 mg/kg in 5 minutes). Bipolar EGMs were considered abnormal (aEGMs) if they met at least 1 of the following: prolonged duration (>80 ms), fragmented components (at least 2 distinct peaks), and/or late potentials extending beyond the end of the QRS complex. aEGMs duration (Ed) was defined as the time from surface QRS onset in D2 to bipolar EGM offset. Results Fifteen patients were included in the study. Six patients (40%) had history of SCD or inducible ventricular arrhythmias (VAs) at electrophysiological study and 5 patients (33.3%) had a mutation of SCN5A. The mean number of points of EAMs was 1020±500. Patients with history of SCD or VAs compared with patients without history had similar Ed before ajmaline [117.5 ms (100.6–132.5) vs 110.5 ms (106.8–114.8), p=0.72] but longer Ed after ajmaline [247.5 ms (231.6–273.9) vs 188.0 ms (178.0, 211.5), p=0.034]. The best cutoff of Ed after ajmaline to predict VAs history was 233 msec (AUC of the model 0.83, sensitivity: 0.98, specificity: 0.66). Patients with SCN5A mutation compared with patients without had similar Ed before ajmaline [125.2 ms (117.9–132.6) vs 105.0 ms (103.0–119.0), p=0.24] but longer Ed after ajmaline [270.0 ms (259.0–280.5) vs 200.8 ms (181.2–224.2), p=0.037], figure 1. The best cutoff of Ed after ajmaline to predict SCN5A mutation was 256.5 ms (AUC of the model 0.84, sensitivity: 0.80, specificity: 0.98), figure 2. Conclusions High density RVOT epicardial mapping provides data of clinical meaning in risk stratification of BrS patients. These data should be interpreted in the context of a population undergone RVOT-EPI substrate ablation. Funding Acknowledgement Type of funding sources: None. aEGM duration and SCD/VA or SCN5AROC curves for EGM derived prediction

Aims To evaluate the clinical outcome in patients undergoing repeat procedures for recurrent persistent atrial fibrillation following an index cryoballoon (CB‐A) pulmonary vein isolation ablation on a mid‐term follow‐up of 12 months. Methods In this propensity score‐matched comparison, 50 patients undergoing left atrial posterior wall isolation (LAPWI) with the CB‐A were matched to 50 patients treated with additional linear ablation using radiofrequency catheter ablation (RFCA). Results Meantime to repeat the procedure was 9.74 ± 4.36 months. At 12 months follow‐up freedom from atrial tachyarrhythmias (ATas) was achieved in 82% of patients in the LAPWI group and in 62% of patients in the linear ablation group (P = .03). Regression analysis demonstrated that relapses during the blanking period and LA dimensions were independent predictors of ATas recurrences following the repeat procedure. Conclusion LAPWI using CB‐A is associated with a significantly higher freedom from atrial arrhythmias when compared with the RFCA mediated left atrial linear lesions on a mid‐term follow‐up of 12 months in patients with persAF undergoing a redo procedure., LAPWI using CB‐A is associated with a significantly higher freedom from atrial arrhythmias when compared with the RFCA mediated left atrial linear lesions on a mid‐term follow‐up of 12 months in patients with persAF undergoing a redo procedure.

Background: Myxomatous mitral valve prolapse (MVP) and mitral-annular disjunction (Barlow disease) are at-risk for ventricular arrhythmias (VA). Fibrosis involving the papillary muscles and/or the infero-basal left ventricular (LV) wall was reported at autopsy in sudden cardiac death (SCD) patients with MVP. Objectives: We investigated the electrophysiological substrate subtending VA in MVP patients with Barlow disease phenotype. Methods: Twenty-three patients with VA were enrolled, including five with syncope and four with a history of SCD. Unipolar (Uni < 8.3 mV) and bipolar (Bi < 1.5 mV) low-voltage areas were analyzed with electro-anatomical mapping (EAM), and VA inducibility was evaluated with programmed ventricular stimulation (PES). Electrophysiological parameters were correlated with VA patterns, electrocardiogram (ECG) inferior negative T wave (nTW), and late gadolinium enhancement (LGE) assessed by cardiac magnetic resonance. Results: Premature ventricular complex (PVC) burden was 12 061.9 ± 12 994.6/24 h with a papillary-muscle type (PM-PVC) in 18 patients (68%). Twelve-lead ECG showed nTW in 12 patients (43.5%). A large Uni less than 8.3 mV area (62.4 ± 45.5 cm2) was detected in the basal infero-lateral LV region in 12 (73%) patients, and in the papillary muscles (2.2 ± 2.9 cm2) in 5 (30%) of 15 patients undergoing EAM. A concomitant Bi less than 1.5 mV area (5.0 ± 1.0 cm2) was identified in two patients. A history of SCD, and the presence of nTW, and LGE were associated with a greater Uni less than 8.3 mV extension: (32.8 ± 3.1 cm2 vs. 9.2 ± 8.7 cm2), nTW (20.1 ± 11.0 vs. 4.1 ± 3.8 cm2), and LGE (19.2 ± 11.7 cm2 vs. 1.0 ± 2.0 cm2, p =.013), respectively. All patients with PM-PVC had a Uni less than 8.3 mV area. Sustained VA (ventricular tachycardia 2 and VF 2) were induced by PES only in four patients (one with resuscitated SCD). Conclusions: Low unipolar low voltage areas can be identified with EAM in the basal inferolateral LV region and in the papillary muscles as a potential electrophysiological substrate for VA and SCD in patients with MVP and Barlow disease phenotype.

Mitral valve prolapse (MVP) is the most common valvular heart disease, affecting 2–3% of the general population. Barlow’s disease is a clinical syndrome characterised by MVP. Initially thought a benign condition, MVP is now recognised as a cause of sudden cardiac death and ventricular arrhythmias. The development of new imaging techniques has contributed recently to the identification of novel risk factors. Catheter ablation of ventricular arrhythmias in patients affected by MVP is traditionally considered challenging. In this review, the authors summarise the evidence on arrhythmogenesis in the context of MVP, along with risk stratification of sudden cardiac death and the available treatment options, including new catheter ablation techniques.