Comparison of efficacy of pulmonary vein isolation between cryoballoon ablation and high-power short-duration ablation.

BACKGROUND: High-power short-duration (HPSD) and cryoballoon ablation (CBA) has been used for pulmonary vein isolation (PVI). OBJECTIVE: We aimed to compare the efficacy of PVI between CBA and HPSD ablation in patients with paroxysmal atrial fibrillation (PAF). METHODS: We retrospectively analyzed 251 consecutive PAF patients from January 2018 to July 2020. Of them, 124 patients (mean age 57.2 ± 10.1 year) received HPSD and 127 patients (mean age 59.6 ± 9.4 year) received CBA. In HPSD group, the radiofrequency energy was set as 50 W/10 s at anterior wall and 40 W/10 s at posterior wall. In CBA group, 28 mm s generation cryoballoon was used for PVI according the guidelines. RESULTS: There was no significant difference in baseline characteristics between these 2 groups. The time to achieve PVI was significantly shorter in cryoballoon ablation group than in HPSD group (20.6 ± 1.7 min vs 51.8 ± 36.3, P = 0.001). The 6-month overall recurrence for atrial tachyarrhythmias was not significantly different between the two groups (HPSD:14.50% vs CBA:11.0%, P = 0.40). There were different types of recurrent atrial tachyarrhythmia between these 2 groups. Recurrence as atrial flutter was significantly more common in CBA group compared to HPSD group (57.1% vs 12.5%, P = 0.04). CONCLUSION: In PAF patients, CBA and HPSD had a favourable and comparable outcome. The recurrence pattern was different between CBA and HPSD groups.

Percutaneous Left Atrial Appendage Closure Using an Occluder Device: A Single Center Experience.

Background: Left atrial appendage (LAA) is the main source of thrombus formation, and occlusion of this structure decreases the risk of stroke in patients with atrial fibrillation. Objectives: We aimed to describe the feasibility, safety and outcomes of percutaneous LAA closure using an occluder device, and to evaluate residual LAA contrast leak detected on computed tomography (CT) imaging in patients who underwent implantation in our institution. Methods: Consecutive patients of Taipei Veterans General Hospital who underwent percutaneous implantation of an LAA occluder (LAAO) were retrospectively collected and analyzed. Results: A total of 23 patients were included with a median age of 67 years (42-87) and median CHA2DS2-VASc score of 4 (1-7). The most frequent indication for intervention was bleeding while on oral anticoagulation treatment. After a mean follow-up of 31.17 ± 25.10 months, successful device implantation was achieved in 95.7% of the patients. There was no occurrence of death, stroke, device embolization, acute ST elevation myocardial infarction, major bleeding requiring invasive treatment or blood transfusion, inguinal hematoma or major bleeding related to antiplatelet therapy. One patient had cardiac tamponade, 1 had intra-procedural thrombus formation, 1 had impingement of mitral valve leaflet, and 1 had device-related thrombosis. Of 12 patients who underwent CT post- implantation, 6 had residual contrast leak into the LAA, one third of those who had peri-device leak. Conclusions: Percutaneous implantation of an LAAO appeared to be feasible with a low risk of major complications.

Comparison of lesion characteristics between conventional and high-power short-duration ablation using contact force-sensing catheter in patients with paroxysmal atrial fibrillation.

BACKGROUND: Transmural lesion creation is essential for effective atrial fibrillation (AF) ablation. Lesion characteristics between conventional energy and high-power short-duration (HPSD) setting in contact force-guided (CF) ablation for AF remained unclear. METHODS: Eighty consecutive AF patients who received CF with conventional energy setting (power control: 25-30 W, force-time integral = 400 g s, n = 40) or with HPSD (power control: 40-50 W, 10 s, n = 40) ablation were analyzed. Of them, 15 patients in each conventional and HPSD group were matched by age and gender respectively for ablation lesions analysis. Type A and B lesions were defined as a lesion with and without significant voltage reduction after ablation, respectively. The anatomical distribution of these lesions and ablation outcomes among the 2 groups were analyzed. RESULTS: 1615 and 1724 ablation lesions were analyzed in the conventional and HPSD groups, respectively. HPSD group had a higher proportion of type A lesion compared to conventional group (P < 0.01). In the conventional group, most type A lesions were at the right pulmonary vein (RPV) posterior wall (50.2%) whereas in the HPSD group, most type A lesions were at the RPV anterior wall (44.0%) (P = 0.04). The procedure time and ablation time were significantly shorter in the HPSD group than that in the conventional group (91.0 ± 12.1 vs. 124 ± 14.2 min, P = 0.03; 30.7 ± 19.2 vs. 57.8 ± 21 min, P = 0.02, respectively). At a mean follow-up period of 11 ± 1.4 months, there were 13 and 7 patients with recurrence in conventional and HPSD group respectively (P = 0.03). CONCLUSION: Optimal ablation lesion characteristics and distribution after conventional and HPSD ablation differed significantly. HPSD ablation had shorter ablation time and lower recurrence rate than did conventional ablation.

Deep Sedation with Intravenous Anesthesia Is Associated with Outcome in Patients Undergoing Cryoablation for Paroxysmal Atrial Fibrillation.

Whether deep sedation with intravenous anesthesia will affect the recurrence after cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (AF) is yet to be examined. Thus, in this study, we hypothesize that there is difference in terms of the recurrence between local anesthesia and deep sedation with intravenous anesthesia after an index ablation procedure.In total, 109 patients were enrolled and received CBA, of which 68 (58.2 years) patients underwent pulmonary vein (PV) isolation with a local anesthesia (group 1) and 41 patients (63.2 years) underwent PV isolation with deep sedation using intravenous anesthesia (group 2).During the index procedure, isolation of all major PVs was achieved in 66 patients in group 1 and in 41 patients in group 2. There was no difference in non-PV triggers between the two groups. The periprocedural complication was found to be similar between the two groups (2.9% in group 1 and 4.9% in group 2). Further, 17 patients in group 1 and 4 patients in group 2 experienced recurrences after a follow-up of 19.3 months (P = 0.019). Repeat procedures revealed similar PV reconnection rates between the two groups. It has also been noted that the number of reconnected PV and incidence of atypical flutter seem to increase in group 1.Deep sedation with intravenous anesthesia during CBA for paroxysmal AF is safe and had a better long-term outcome than those with local anesthesia.

Case series on stereotactic body radiation therapy in non-ischemic cardiomyopathy patients with recurrent ventricular tachycardia.

INTRODUCTION: The efficacy of stereotactic body radiation therapy (SBRT) as an alternative treatment for recurrent ventricular tachycardia (VT) is still unclear. This study aimed to report the outcome of SBRT in VT patients with nonischemic cardiomyopathy (NICM). METHODS: The determination of the target substrate for radiation was based on the combination of CMR results and electroanatomical mapping merged with the real-time CT scan image. Radiation therapy was performed by Flattening-filter-free (Truebeam) system, and afterward, patients were followed up for 13.5 ± 2.8 months. We analyzed the outcome of death, incidence of recurrent VT, ICD shocks, anti-tachycardia pacing (ATP) sequences, and possible irradiation side-effects. RESULTS: A total of three cases of NICM patients with anteroseptal scar detected by CMR. SBRT was successfully performed in all patients. During the follow-up, we found that VT recurrences occurred in all patients. In one patient, it happened during a 6-week blanking period, while the others happened afterward. Re-hospitalization due to VT only appeared in one patient. Through ICD interrogation, we found that all patients have reduced VT burden and ATP therapies. All of the patients died during the follow-up period. Radiotherapy-related adverse events did not occur in all patients. CONCLUSIONS: SBRT therapy reduces the number of VT burden and ATP sequence therapy in NICM patients with VT, which had a failed previous catheter ablation. However, the efficacy and safety aspects, especially in NICM cases, remained unclear.

Optimal substrate modification strategies using catheter ablation in patients with persistent atrial fibrillation: 3-year follow-up outcomes.

OBJECTIVES: This study aimed to assess the comparative efficacy of four ablation strategies on the incidence rates of freedom from atrial fibrillation (AF) or atrial tachycardia (AT) through a 3-year follow-up in patients with persistent AF. BACKGROUND: The optimal substrate modification strategies using catheter ablation for patients with persistent AF remain unclear. METHODS: Patients with persistent AF were enrolled consecutively to undergo each of four ablation strategies: (a) Group 1 (Gp 1, n = 69), pulmonary vein isolation (PVI) plus rotor ablation assisted by similarity index and phase mapping; (b) Gp 2 (n = 75), PVI plus linear ablations at the left atrium; (c) Gp 3 (n = 42), PVI plus the elimination of complex fractionated atrial electrograms; (d) Gp 4 (n = 67), PVI only. Potential confounders were adjusted via a multivariate survival parametric model. RESULTS: Baseline characteristics were similar across the four groups. At a follow-up period of 34.9 ± 38.6 months, patients in Gp 1 showed the highest rate of freedom from AF compared with the other three groups (p = .002), while patients in Gp 3 and 4 showed lower rates of freedom from AT than those of the other two groups (p = .006). Independent predictors of recurrence of AF were the ablation strategy (p = .002) and left atrial diameter (LAD) (p = .01). CONCLUSION: In patients with persistent AF, a substrate modification strategy using rotor ablation assisted by similarity index and phase mapping provided a benefit for maintaining sinus rhythm compared with the other strategies. Both ablation strategy and baseline LAD predicted the 3-year outcomes of freedom from AT/AF.

Effects of Angiotensin Receptor-Neprilysin Inhibitor in Arrhythmogenicity Following Left Atrial Appendage Closure in an Animal Model.

PURPOSE: Left atrial appendage (LAA) closure decreases atrial natriuretic peptide (ANP) levels, which indirectly increases the risk of arrhythmogenicity. We aimed to determine the effect of a combined angiotensin receptor-neprilysin inhibitor (ARNi) on arrhythmogenicity following LAA closure in an animal model. METHODS: Twenty-four rabbits were randomized into four groups: (1) control, (2) LAA closure (LAAC), (3) heart failure (HF)-LAAC, and (4) HF-LAAC with sacubitril/valsartan (+ARNi). HF models were developed in the HF-LAAC and HF-LAAC+ARNi groups. Epicardial LAA exclusion was performed in the LAAC, HF-LAAC, and HF-LAAC+ARNi groups. ANP levels were measured. An electrophysiological study was performed. The myocardium was harvested for histopathological analysis. RESULTS: The ANP level decreased in the LAAC group (785 ± 103 pg/mL, p = 0.03), failed to increase in the HF-LAAC group (917 ± 172 pg/mL, p = 0.3), and increased in the HF-LAAC+ARNi group (1524 ± 126 pg/mL, p < 0.01) compared to that in the control group (1014 ± 56 pg/mL). The atrial effective refractory period (ERP) was prolonged in the HF-LAAC group and restored to baseline in the HF-LAAC+ARNi group. Ventricular ERP was the longest in the HF-LAAC group. The atrial fibrillation window of vulnerability (AF WOV) was elevated in the LAAC, HF-LAAC, and HF-LAAC+ARNi groups, with the latter group having lower AF WOV than the two former groups. Ventricular fibrillation (VF) inducibility was the highest in the HF-LAAC group (51 ± 5%, p < 0.001), followed by the LAAC group (30 ± 4%, p = 0.006) and the HF-LAAC+ARNi group (25 ± 5%, p = 0.11) when compared to the control group (18 ± 4%). Atrial and ventricular fibrosis were noted in all groups except the control group. CONCLUSION: LAA closure decreased ANP, which in turn increased AF and VF inducibility. Atrial and ventricular arrhythmogenicity was suppressed by ARNi.

Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC. METHODS AND RESULTS: Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P < 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves. CONCLUSION: The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.

Spatiotemporal differences in precordial electrocardiographic amplitude before and after flecainide provocation are associated with a history of unstable ventricular arrhythmia in Brugada syndrome.

INTRODUCTION: A drug provocation test (DPT) is important for the diagnosis of Brugada syndrome (BrS). The link, however, between dynamic changes of electrocardiography (ECG) features after DPT and unstable ventricular arrhythmia (VA) in BrS remains unknown. METHODS: Between 2014 and 2019, we assessed 27 patients with BrS (median age: 37.0 [interquartile range, IQR: 22.0-51.0] years; 25 men), including 9 (33.3%) with a history of unstable VA and 18 (66.7%) without. All patients in the study presented with Brugada-like ECG features before DPT. The ECG parameters and dynamic changes (∆) in 12-lead ECGs recorded from the second, third, and fourth intercostal spaces (ICS) before and at 1, 6, 12, 18, and 24 h after DPT (oral flecainide 400 mg) were analyzed. RESULTS: The total amplitude of V1 at the third ICS 18 and 24 h after DPT was significantly lower in patients with a history of unstable VA than in those without. Patients with BrS and unstable VAs had a significantly larger ∆ amplitude of V1 at the second ICS 12 h after DPT than in those without unstable VAs (0.28 [0.18-0.41] mV vs. 0.08 [0.01-0.15] mV, p = .01). A multivariate analysis revealed that the amplitude of V1 at the third ICS 18 and 24 h after DPT and the ∆ amplitude of V1 at the second ICS 12 h after DPT were associated with a history of unstable VA. CONCLUSION: Nonuniform changes and spatiotemporal differences in precordial ECG features after DPT were observed in patients with BrS and these may be surrogate markers for risk stratification.

Catheter ablation of complex atrial tachyarrhythmias in adult patients with cor triatriatum.

PURPOSE: Reports concerning clinical characteristics of cor triatriatum and approaches for catheter ablation of complex atrial tachyarrhythmias remain limited. Here, we describe successful catheter ablation treatments for complex atrial tachyarrhythmias in patients with cor triatriatum and address the clinical caveats. METHODS: Demographic characteristics, electrophysiologic findings, and ablation results in four patients with cor triatriatum were described. RESULTS: Catheter ablation was performed in four patients with cor triatriatum (three sinister and one dexter) and complex atrial arrhythmias (three with persistent atrial fibrillation (AF) and one with atypical left atrial flutter). A transseptal puncture was selectively directed into the accessory compartment containing the pulmonary veins. A comprehensive preview involving transthoracic echocardiography, transesophageal echocardiography, and computed tomography of the pulmonary veins was critical for proper positioning of ablation catheters. The pulmonary veins remain the major triggers or initiators for AF, and four pulmonary vein isolation procedures were sufficient to achieve successful results with negative inducibility test in the patients with AF. Heterogeneous conduction and complex fractionated signals were observed on the fibromuscular membrane. Atypical flutter was terminated during ablation over the connection between membrane and left atrial roof. The procedure was successfully performed on all patients without complications. No acute recurrences of atrial tachyarrhythmias were observed in any of the patients during short-term follow-up. CONCLUSIONS: Catheter ablation is a feasible and efficient therapeutic strategy for treating complex atrial tachyarrhythmias in patients with cor triatriatum. Atrial remodeling due to anatomical obstruction or heterogeneous conduction of the fibromuscular membrane may serve as an arrhythmic substrate.

Outcome of rescue ablation in patients with refractory ventricular electrical storm requiring mechanical circulation support.

BACKGROUND: The management of refractory electrical storm (ES) requiring mechanical circulation support (MCS) remains a clinical challenge in structural heart disease (SHD). OBJECTIVE: The study sought to explore the 30-day and 1-year outcome of rescue ablation for refractory ES requiring MCS in SHD. METHODS: A total of 81 patients (mean age: 55.3 ± 18.9, 73 men [90.1%]) undergoing ablation were investigated, including 26 patients with ES requiring MCS (group 1) and 55 patients without (group 2). The 30-day and 1-year outcome, including mortality and recurrent ventricular tachyarrhythmias (VAs) receiving appropriate implantable cardioverter defibrillators therapies, were assessed. RESULTS: The patients in group 1 were characterized by older age, more ischemic cardiomyopathies, worse left ventricular ejection fraction, and more comorbidities. Thirty days after ablation, overall events were seen in 15 patients (mortality in 10 and recurrent VA in 7), including pumping failure-related mortality in 6 (60%). During a 30-day follow-up, higher mortality was noted in group 1. After a 1-year follow-up, in spite of the higher mortality in group 1 (P < .001), the overall events and VA recurrences were similar between these two groups (P = .154 and P = .466, respectively). There was a significant reduction of VA burden in both groups and two patients had recurrent ES. CONCLUSION: Higher 30-day mortality was observed in patients undergoing rescue ablation for refractory ES requiring MCS, and pumping failure was the major cause of periprocedural death. Rescue ablation successfully prevented VA recurrences and resulted in a comparable 1-year prognosis between ES with and without MCS.

Application of noninvasive signal-averaged electrocardiogram analysis in predicting the requirement of epicardial ablation in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Signal-averaged electrocardiogram (SAECG) provides not only diagnostic information but also the prognostic implication of ablation in arrhythmogenic right ventricular cardiomyopathy (ARVC). OBJECTIVE: This study aimed to validate the role of SAECG in identifying arrhythmogenic substrates requiring an epicardial approach in ARVC. METHODS: Ninety-one patients with a definite diagnosis of ARVC who underwent successful ablation for drug-refractory ventricular arrhythmia were enrolled and classified into 2 groups: group 1 who underwent successful ablation at the endocardium only and group 2 who underwent successful ablation requiring an additional epicardial approach. The baseline characteristics of patients and SAECG parameters were obtained for analysis. RESULTS: Male predominance, worse right ventricular (RV) function, higher incidence of syncope, and depolarization abnormality were observed in group 2. Moreover, the number of abnormal SAECG criteria was higher in group 2 than in group 1. After a multivariate analysis, the independent predictors of the requirement of epicardial ablation included the number of abnormal SAECG criteria (odds ratio 2.8, 95% confidence interval 1.4-5.4; P = .003) and presence of syncope (odds ratio 11.7; 95% confidence interval 2.7-50.4; P = .001). In addition, ≥2 abnormal SAECG criteria were associated with larger RV endocardial unipolar low-voltage zone (P < .001), larger RV endocardial/epicardial bipolar low-voltage zone/scar (P < .05), and longer RV endocardial/epicardial total activation time (P < .001 and P = .004, respectively). CONCLUSION: The number of abnormal SAECG criteria was correlated with the extent of diseased epicardial substrates and could be a potential surrogate marker for predicting the requirement of epicardial ablation in patients with ARVC.