A 70-year-old man presented with regular wide QRS complex tachycardia (WCT) at a rate of 185 beats/min, characterized by left bundle branch block morphology. WCT termination was achieved through electrical cardioversion. A subsequent 12-lead electrocardiogram revealed sinus rhythm with complete right bundle branch block (CRBBB) morphology. Echocardiography showed normal left ventricular function without structural heart disease. An electrophysiological study was then conducted, followed by catheter ablation. At baseline, the atrio-His and His-ventricular intervals were normal. Fractionated ventricular potentials were observed in the para-Hisian region during sinus rhythm. Neither dual atrioventricular (AV) nodal physiology nor ventriculoatrial conduction was observed during programmed pacing. Clinical WCT was induced by ventricular extra-stimulation with concurrent AV dissociation and no visual His bundle potential, confirming the diagnosis of ventricular tachycardia (VT). Figure 1 illustrates 12-lead electrocardiograms recorded during overdrive pacing from the right ventricular apex (RVA) and right atrial septum during VT. The electroanatomical activation map revealed a distinctive focal breakout pattern with fractionated potentials originating from the para-Hisian region. In the noncoronary cusp (NCC), corresponding to the opposite side of the para-Hisian region, prolonged and fractionated ventricular potentials preceding QRS onset by 56 ms were recorded (Figure 2A). Figure 2B shows the intracardiac electrogram recorded during ventricular overdrive pacing from the NCC during VT. Based on these observations, what is the mechanisms underlying the tachycardia?

The limited literature and increasing interest in studies on cardiac electrophysiology, explicitly focusing on cardiac ion channelopathies and sudden cardiac death (SCD) in diverse populations, has prompted a comprehensive examination of existing research. Our review specifically targets Hispanic/Latino and Indigenous populations, which are often underrepresented in healthcare studies. This review encompasses investigations into genetic variants, epidemiology, etiologies, and clinical risk factors associated with arrhythmias in these demographic groups. The review explores the Hispanic paradox, a phenomenon linking healthcare outcomes to socioeconomic factors within Hispanic communities in the United States. Furthermore, it discusses studies exemplifying this observation in the context of arrhythmias and ion channelopathies in Hispanic populations. Current research also sheds light on disparities in overall healthcare quality in Indigenous populations. The available yet limited literature underscores the pressing need for more extensive and comprehensive research on cardiac ion channelopathies in Hispanic/Latino and Indigenous populations. Specifically, additional studies are essential to fully characterize pathogenic genetic variants, identify population-specific risk factors, and address health disparities to enhance the detection, prevention, and management of arrhythmias and SCD in these demographic groups.

Background: Pulsed field ablation (PFA) is a novel technique for pulmonary vein isolation in atrial fibrillation management. Notably, asystole episodes of varying durations have been observed during electroporation, but the underlying mechanisms remain unclear. Objective: This study hypothesizes that asystole during PFA is attributable to the activation of parasympathetic ganglia on the left atrium’s surface. Methods: We conducted a study with 24 patients (67% male, 62.8 ± 11.0 years, BMI: 25.3 ± 5.6) suffering from paroxysmal atrial fibrillation. The order of pulmonary veins chosen for electroporation was randomized to avoid cumulative electroporation effects. PFA was performed and the duration of cardiac pauses post-electroporation was recorded for each application. To examine the impact of electroporation on the parasympathetic nervous system, transjugular vagal stimulation (TJVS) was performed from the right internal jugular before and after isolation of each vein, during sinus rhythm and atrial pacing. Continuous data were analyzed with Student’s t-tests or Mann-Whitney U tests as appropriate; nominal data were evaluated using chi-square or Fisher exact tests. Results: Pre-PFA TJVS induced sinus pauses of 10.1 ± 2.74 seconds. A sinus block of over 3 seconds was present in 23 out of 24 patients. Post-PFA, the Right Superior Pulmonary Vein (RSPV) showed the highest decrease of TJVS-induced sinus pauses (RSPV: before 8.41 ± 4.53 vs after 3.27 ± 3.53 sec, p<0.001, RIPV: before 6.76 ± 4.54 sec vs. 6.89 ± 5.07 sec, p=0.90; LSPV: before 6.76 ± 5.25 sec vs. after 6.93 ± 4.29 sec, p=0.61; LIPV: before 7.80 ± 4.06 sec vs. after 7.88 ± 3.84 sec, p=0.91). Notably, sinus blocks over 3 seconds decreased significantly after RSPV ablation (19 before PFA, 10 after PFA, p<0.01), with less dramatic changes in other veins (RIPV: before 19, after 16, p=0.33; LSPV: before 14, after 19, p=0.11; LIPV: before 21, after 21, p=1.00). RSPV PFA also had the strongest impact on TJVS-induced AV block duration compared to the remaining veins (RSPV: before 6.49 ± 3.48 vs after 4.07 ± 3.27 sec, p<0.01, RIPV: before 6.00 ± 3.29 sec vs. 4.58 ± 3.99 sec, p=0.08; LSPV: before 5.15 ± 3.94 sec vs. after 5.14 ± 3.48 sec, p=0.93; LIPV: before 6.06 ± 3.98 sec vs. after 5.83 ± 3.44 sec, p=0.38). The incidence of AV blocks over 3 seconds was markedly reduced post-RSPV and post RIPV ablation (RSPV: before:19 vs. after: 14, p=0.11, RIPV: before:19 vs. after: 14, p=0.11), with minor changes in other veins (LSPV: before 14, after 16, p=0.55; LIPV: before 17, after 18, p=0.77). Conclusions: PFA applications during pulmonary vein isolation have acute effect on the autonomic nervous system, as evidenced by the decrease in TJVS-induced sinus and atrioventricular block at the level of the right superior pulmonary vein. PFA-induced pauses are more frequent during applications on the LSPV, and less frequent when prior isolation of the RSPV has been performed, suggesting a vagally-mediated mechanism involving the right superior and/or right posterior ganglionated plexi.

Background Previous research indicates disparities in atrial fibrillation (AF) recurrence and complications following catheter ablation in women; however, long-term outcomes based on gender remain underexplored. Objective This study evaluated the long-term rates of AF recurrence and major adverse cardiovascular and cerebrovascular events (MACCE) following catheter ablation, investigating gender-related risk factors to inform clinical practice improvement. Methods We conducted a retrospective analysis using data from a prospectively observational registry of AF ablation procedures at our institution from 2015 to 2020. Patients were followed up for MACCE and AF recurrence. The risk factors of AF recurrence and MACCE were further explored. Results The study cohort consisted of 2,293 patients, including 1,441 males and 852 females, and had an average follow-up duration of 50.36 months. After catheter ablation, females exhibited a notably higher rate of recurrence compared to males, with a hazard ratio of 1.305 and a 95% confidence interval ranging from 1.101 to 1.547, which was statistically significant (p=0.0014). Gender differences in AF recurrence persisted regardless of early versus late intervention (both p<0.05). No significant difference in MACCE rates was observed between genders. Independent risk factors for AF recurrence included female gender, diabetes, left atrial diameter ≥40 mm. Conclusions Gender differences significantly impact the long-term outcomes of AF recurrence, but not MACCE rates post-catheter ablation. The study highlights the necessity to integrate gender considerations into AF management strategies.

Introduction: The aim of this study was to describe our experience and outcome of ablation therapy of arrhythmias in children at a tertiary care center. Methods: Data was collected retrospectively from the hospital medical records. All children presenting to AUBMC between 2000 and 2020 who underwent cardiac ablation were included. The data collected included type of arrhythmia, ablation technique, age and weight at ablation, procedure complications, medications used, and outcome assessment. Results: We had 67 patients who underwent cardiac ablation. Of those, 60% were males with a mean age of 15 years. Structural heart disease was present in 6% of patients. Wolff-Parkinson-White syndrome (WPW) was most prevalent at 31%, followed by atrioventricular nodal reentrant tachycardia (AVNRT) at 24%, atrioventricular reentrant tachycardia (AVRT) at 19%, ventricular tachycardia (VT) at 10%, atrial fibrillation (AF) at 2%, and atrial tachycardia (AT) at 1%. The remaining 13% of patients presented with less common types of arrhythmias, including narrow complex tachycardia, retrograde dual atrioventricular nodal reentry, premature ventricular contractions (PVC), and orthodromic reciprocating tachycardia. Antiarrhythmic medications were started prior to the procedure in 59% of our population. Medication regimens post-ablation included beta blockers (68%), type 1c antiarrhythmics (25%), calcium channel blockers (3%), ivabradine (2%), and amiodarone (2%). The completed procedures showed a success rate of 93%. Conclusion: Ablation of arrhythmias in children is an effective procedure in the treatment of childhood arrhythmias. More studies are needed on cardiac ablation in children with structural heart disease in the Middle East region.

INTRODUCTION: Inappropriate sinus tachycardia (IST) is a common condition with frequently not tolerated beta-blockers or ivabradine and a high rate of complication in ablation strategy; we describe an alternative anatomical approach of sinus node modulation. METHODOLOGY: This retrospective study describes a case series of 6 patients from two centers diagnosed with symptomatic IST undergoing sinus node ablation. RESULTS: The mean age was 40.6 ± 13.9 years; five of the six patients were female, 100% of patients reported heart palpitations, and 66% reported dizziness, the average HR on a 24-h Holter was 93.2 ±7.9 bpm. HR during the first stage of a stress test using a standard Bruce protocol was 150 ±70 bpm, The average HR on 24-hour Holter post-ablation was 75 ± 5.6 bpm, the sinus rate HR during stage 1 of a Bruce protocol exercise stress test was 120 ± 10 bpm. CONCLUSION: This is the first case series reporting the acute and long-term results of a novel anatomical approach for SNM to treat IST targeting the AR under ICE guidance, The novel anatomic ICE-guided catheter ablation approach aimed to identify the earliest activation at the AR with an extension of RF lesions towards its septal region seems effective and safe to modulate the SN in symptomatic patients with IST refractory to medical treatment.

Introduction: Post-ablation chest pain is a common occurrence in patients after radiofrequency (RF) pulmonary vein isolation (PVI) ablation for the treatment of atrial fibrillation (AF), with a reported incidence of up to 50%. Pain can be caused by pericarditis, vagal plexus thermal injury, gastroparesis, or local inflammation. Active esophageal cooling is FDA cleared for reducing the likelihood of ablation-related esophageal injury resulting from RF cardiac ablation procedures, but cooling has also been reported to have pleiotropic effects which may mitigate inflammation and reduce the likelihood of post-ablation chest pain. The aim of this study is to quantify the change in incidence of post-ablation chest pain after the adoption of active esophageal cooling during RF ablations. Methods: Data from a community hospital registry were obtained for the 12 months prior to (pre-adoption), and the 12 months after adoption (post-adoption) of active esophageal cooling in December 2021 during RF ablations. Type of ablation was recorded, along with patient’s age, post-ablation symptoms, and type of prophylactic treatment utilized. Incidence rates of chest pain before and after adoption of esophageal cooling were then compared. Results: Data were reviewed from 183 patients. In the pre-adoption cohort, patients were given 2 weeks of daily sucralfate and pantoprazole, with an additional 4 weeks in cases with persisting symptoms. In this group, 90 patients (66.7% persistent AF) with a mean age of 69.6 years (SD ± 10.34) received PVI, with 62 (68.9%) receiving roof lines, 60 (66.7%) receiving floor lines, and 41 (45.6%) reporting post-ablation chest pain requiring extension of treatment to 6 weeks. In the post-adoption cohort, 2 days of sucralfate and pantoprazole was given, and a total of 93 patients (75.2% persistent AF) with a mean age of 68.3 years (SD ± 10.28) received PVI, with 79 (84.5%) receiving roof lines, 75 (80.6%) receiving floor lines, and none reporting post-ablation chest pain (p<0.0001). Conclusion: Adoption of active esophageal cooling was associated with a significant reduction in post-ablation chest pain despite increased use of posterior wall isolation and decreased use of prophylactic treatment.

Background: Cather ablation (CA) is a well-recognized treatment alternative for atrial fibrillation (AF) patients despite more than 20% ablation-treated patients suffering from AF recurrence. The underlying mechanism of AF recurrence post-ablation is probably associated with high cardiac parasympathetic activity, which can be assessed with deceleration capacity (DC) of heart rate. Given that the relationship between DC and AF recurrence is still controversial, this systematic review and meta-analysis was performed to investigate the characteristics of DC in patients with and without AF recurrence, evaluating the prognostic value of DC in AF patients after CA. Methods: A literature search was systematically performed in the Embase, PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang databases until October 01, 2023. The observational studies reporting either the pre- and post-ablation DC in both recurrence and non-recurrence groups or the ratios based on DC for predicting AF recurrence were mainly included. Weighted mean differences (WMD) or odds ratios (OR) based on DC would be calculated with a random-effect model, if heterogeneity estimated with the I 2 index and Q statistic was significant ( I 2 > 50% or P < .05); otherwise, a fixed-effect model would be utilized. Results: A total of 8 observational studies involving 914 AF patients treated with radiofrequency or cryoballoon ablation were included in this study. Ablation-treated patients with AF recurrence had the higher DC post-ablation in relation to those without recurrence (WMD, 1.00; 95%CI, 0.33 to 1.67; P < .01), which was present up to 3 months of follow-up (WMD, 1.54; 95%CI, 1.11 to 1.96; P < .01), whereas there was no statistical significance in DC prior to ablation between recurrence and non-recurrence groups (WMD, 0.34; 95%CI, -0.12 to 0.79; P = .15). The high DC post-ablation was a risk factor for AF recurrence in ablation-treated patients (OR, 2.17; 95%CI, 1.44 to 3.25; P < .01). Conclusion: The high DC post-ablation was associated with the risk of AF recurrence, suggesting that DC may act as a prognostic indicator in AF patients treated with CA. Keywords: Deceleration capacity; Atrial fibrillation; Catheter ablation; Recurrence; Meta-analysis; Systematic review.

An 80-year-old man had a secondary prevention defibrillator in place for treatment of sustained ventricular tachycardia. After a generator replacement several years later, he developed a series of apparent pulse generator infections requiring extraction. Each purulent appearing pocket eruption was culture negative. Eventually, he was diagnosed with a delayed hypersensitivity reaction to triclosan, an antibacterial that is commonly impregnated in surgical sutures. The evaluation for this is difficult and can be misleading. This entity should be considered in the differential diagnosis of patients with culture negative CIED infections.

Background: New-onset atrial fibrillation (NOAF) in COVID-19 raises significant clinical and public health issues. This systematic review and meta-analysis aims to compile and analyze the current literature on NOAF in COVID-19 and give a more comprehensive understanding of the prevalence and outcomes of NOAF in COVID-19. Methods: A comprehensive literature search was carried out using several databases. The random effect model using inverse variance method and DerSimonian and Laird estimator of Tua2 was used to calculate the pooled prevalence and associated 95% confidence interval (CI). Results for outcome analysis were presented as odds ratios (ORs) with 95% CI and pooled using the Mantel-Haenszel random-effects model. Results: The pooled prevalence of NOAF in COVID-19 was 7.8% (95% CI, 6.54% to 9.32%), pooled estimate from 30 articles (81,929 COVID-19 patients). Furthermore, our analysis reported that COVID-19 patients with NOAF had a higher risk of developing severe disease compared with COVID–19 patients without a history of atrial fibrillation (OR= 4.78, 95% CI 3.75 to 6.09) and COVID-19 patients with a history of pre-existing atrial fibrillation (OR= 2.75, 95% CI 2.10 to 3.59) . Similarly, our analysis also indicated that COVID–19 patients with NOAF had a higher risk of all-cause mortality compared with, COVID–19 patients without a history of atrial fibrillation (OOR= 3.83, 95% CI 2.99 to 4.92) and COVID-19 patients with a history of pre-existing atrial fibrillation (OR= 2.32, 95% CI 1.35 to 3.96). The meta-analysis did not reveal any significant publication bias. Conclusion: The results of the current meta-analysis a high prevalence rate of NOAF among COVID-19 patients. Further the study reported higher disease severity with NOAF compared with COVID-19 patients without a history of atrial fibrillation and with a history of atrial fibrillation.

Introduction: Atrial tachycardia(AT) occurring from the right atrial appendage(RAA) is relatively uncommon, while the catheter ablation is complicated by the anatomic characteristics. Methods: We reported a case of 60-year-old male patient who was admitted with incessant AT. Results: The tachycardia activation mapping demonstrated that the AT originated from the tip of RAA. Pulsed field ablation(PFA) using the circular mapping&PFA catheter terminated AT without any complication. Conclusions: This case corroborates that PFA might be an alternative strategy for ablation of atrial arrhythmia originating from the atrial appendage.

Background Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra-cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA. Objective This study aimed to compare the long-term follow-up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS. Method A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1±2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing. Results Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow-up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9±20 months for the NoECVS group (p=0.24). Notably, syncope recurrence was significantly lower in the ECVS group (2 cases vs. 4 cases, Log Rank p=0.04). Moreover, the Hazard ratio revealed a five-fold higher risk of syncope recurrence in the NoECVS group. Conclusion This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation.

Background Acute pulmonary vein reconnection via epicardial fibers can be found during observation period after PV isolation, the characteristics and related factors have not been fully studied. Objective To investigate the prevalence, locations, electrogram characteristics and ablation parameters related to acute epicardial pulmonary vein reconnection (AEPVR). Methods Acute PVR was monitored during observation period after PV isolation, from which AEPVRs were mapped and distinguished from endocardial conduction gaps. The clinical, electrophysiological characteristics and lesion set parameters were compared between patients with and without PVR. So were they compared among AEPVR, gap-related reconnection, and epicardial PVR in repeat procedures. Results 56.1% acute PVR were AEPVR, which required a longer waiting period ( P<0.001) than endocardial gap. The majority of AEPVR were connections from the posterior PV antrum to the left atrial posterior wall, followed by late manifestation of intercaval bundle conduction from the right anterior carina to right atrium. AEPVR was similar to epicardial PVR in redo procedures in distribution and electrogram characteristics. Smaller atrium ( P<0.001), lower impedance drop ( P=0.039) and ablation index ( P=0.028) on the posterior wall were independently associated with presence of AEPVR, while lower inter-lesion distance ( P=0.043) was the only predictor for AEPVR in acute PVR. An integrated model containing multiple lesion set parameters had the highest predictive ability for AEPVR in ROC analysis. Conclusions Epicardial reconduction accounted for the majority of acute PVR. AEPVR was associated with anatomic characteristics and multiple ablation-related parameters, which could be explained by nondurable transmural lesion or late manifestation of non-preferential conduction.

Atrial fibrillation is significantly associated with morbidity and mortality and erodes the quality and quantity of life. It is standard of care to treat patients with AF and an increased risk of stroke with oral anticoagulation therapy, but the more daunting question many clinicians face is whether to pursue a “rate-only” or “rhythm” control strategy. Historical studies over the years have sought to answer this question but have found no significant difference in major clinical outcomes between the two strategies. There are opportunities based on new data to improve the natural history of the disease. The EAST AFnet trial for the first time revealed a significant morbidity and mortality advantage to rhythm control therapy when performed early in the disease process of AF and in the setting of comprehensive medical management that was maintained. The CABANA trial clearly demonstrated that catheter ablation was a more effective long-term treatment of AF in general and significantly lowers risk of AF progression compared to medical therapy. Like multiple prior trials of rhythm management strategies, when rhythm control was effective in these trials, independent of therapy assignment, there was a significantly lower risk of adverse outcomes and death. These contemporary data provide optimism that the pervasive mortality risk in patients with AF observed over the past 50 years may be improved by the timing, use, and efficacy of use of therapeutic interventions.

A document by Jing Li. Click on the document to view its contents.

Introduction: The safety and effectiveness of catheter ablation in patients with atrial fibrillation (AF) who underwent mechanical mitral valve replacement (MVR) have been reported. However, the impacts of different types of mitral valves on the safety and effectiveness of catheter ablation in patients with AF who underwent MVR have not been elucidated. Methods and results: From 2015 to 2021, 17,496 patients underwent catheter ablation of AF for the first time in Beijing Anzhen Hospital were screened. The inclusion criteria were (1) aged 18 years or older; (2) diagnosed with AF; (3) history of mitral valve replacement. The exclusion criteria were a history of catheter ablation, surgical maze procedure, left atrial appendage closure or resection. A total of 68 patients were enrolled in the study. The patients were divided into two groups: the bioprosthetic MVR group (n=12) and the mechanical MVR group(n=58). The size of the left atrial was larger (49.5mm vs. 46.0mm, p<0.05), the thickness of the left interventricular septum was larger (11.0mm vs. 10.0mm, p<0.05), and the mitral ring area was smaller (2.3mm2 vs. 2.6mm2, p<0.05) for the bioprosthetic MVR group than the mechanical MVR group. During 23.4 (6.1, 36.5) months of follow-up, the incidence of the endpoint events was not significantly different between the two groups (33.3% vs. 30.4%, log-rank p=0.48). There were 2 cases (3.4%) of pseudoaneurysm and 1 case of acute cerebral infarction in the mechanical MVR group. No complication was observed in the bioprosthetic MVR group. No significant clinical bleeding events were observed in the bioprosthetic group while eight patients in the mechanical MVR groups had bleeding events (p=0.368) during the follow-up. Conclusion: The safety and effectiveness of catheter ablation of AF were comparable between the patients with mechanical MVR and bioprosthetic MVR.

The QDOT MICROTM Catheter is a novel open-irrigated contact force-sensing single-tip radiofrequency ablation catheter. It incorporates six thermocouples at its tip and offers temperature-controlled and very high-power short-duration (vHPSD) ablation with 90 Watts for 4 seconds to improve safety and efficacy of catheter ablation procedures. The QDOT MICROTM Catheter was recently evaluated for pulmonary vein isolation and safety, efficacy and long-term follow-up found promising results. Although the QDOT MICROTM Catheter was mainly designed for pulmonary vein isolation its versatility to treat atrial fibrillation as well as other types of arrythmias was recently evaluated by the FAST and FURIOUS study series and other studies and will be presented in this article.

Background and Aims: The extravascular implantable cardioverter defibrillator (EV ICD) has an extended projected battery longevity compared to the subcutaneous implantable cardioverter defibrillator (S-ICD). This study used modeling to characterize the need for generator changes, long-term complications, and overall costs for both the EV ICD and S-ICD in healthcare systems of various countries . Methods: Battery longevity data were modelled using a Markov model from averages reported in device labelling for the S-ICD and with engineering estimates based on real life usage from EV ICD Pivotal Study patient data to introduce variability. Clinical demographic data of recipients were derived from published literature. The primary outcomes were defined as the number of generator replacement surgeries, complications, and total healthcare system costs due to battery depletion over the expected lifetime of patients receiving EV ICD or S-ICD therapy. A one-way sensitivity analysis of the model was performed for the US healthcare system. Results: Average modelled battery longevity was determined to be 7.3 years for the S-ICD compared to 11.8 years for the EV ICD. The probability of a complication after a replacement procedure was 1.4%, with an operative mortality rate of 0.02%. The use of an EV ICD was associated with 1.4-1.6 fewer replacements on average over an expected patient lifetime as compared to an S-ICD and a 24.3-26.0% reduction in cost. The US sensitivity analysis found use of an EV ICD resulted in a reduction in replacement surgeries of greater than 1 (1.1-1.6) along with 5-figure cost savings in all scenarios ($18,602-$40,948). Conclusion: The longer projected battery life of the EV ICD compared to the S-ICD has the potential to meaningfully reduce long-term morbidity and healthcare resources related to generator changes from the perspective of multiple diverse healthcare systems.