Asirvatham, Samuel J

Epicardial pulsed field ablation (PFA) of ganglionated plexi (GPs) is being explored as a potential treatment for atrial fibrillation. Initial work using open-chest access with a monopolar ablation device has been completed. This study describes the early development work for a device that can be used with subxiphoid access and deliver bipolar ablation pulses. Electric field computational models have been used for the initial guidance on pulse parameters. An in vivo assessment of these ablation parameters has been performed in an open-chest canine study, while subxiphoid access and navigation of the device has been demonstrated in a porcine model. Results from this acute study have demonstrated the promising potential of this approach.

Abstract Aims ECG abnormalities are often the first signs of arrhythmogenic right ventricular cardiomyopathy (ARVC) and we hypothesized that an artificial intelligence (AI)-enhanced ECG could help identify patients with ARVC and serve as a valuable disease-detection tool. Methods and results We created a convolutional neural network to detect ARVC using a 12-lead ECG. All patients with ARVC who met the 2010 task force criteria and had disease-causative genetic variants were included. All case ECGs were randomly assigned in an 8:1:1 ratio into training, validation, and testing groups. The case ECGs were age- and sex-matched with control ECGs at our institution in a 1:100 ratio. Seventy-seven patients (51% male; mean age 47.2 ± 19.9), including 56 patients with PKP2, 7 with DSG2, 6 with DSC2, 6 with DSP, and 2 with JUP were included. The model was trained using 61 case ECGs and 5009 control ECGs; validated with 7 case ECGs and 678 control ECGs and tested in 22 case ECGs and 1256 control ECGs. The sensitivity, specificity, positive and negative predictive values of the model were 77.3, 62.9, 3.32, and 99.4%, respectively. The area under the curve for rhythm ECG and median beat ECG was 0.75 and 0.76, respectively. Conclusion Our study found that the model performed well in excluding ARVC and supports the concept that the AI ECG can serve as a biomarker for ARVC if a larger cohort were available for network training. A multicentre study including patients with ARVC from other centres would be the next step in refining, testing, and validating this algorithm.

AbstractThe discrimination of ventricular tachycardia (VT) versus supraventricular wide complex tachycardia (SWCT) via 12‐lead electrocardiogram (ECG) is crucial for achieving appropriate, high‐quality, and cost‐effective care in patients presenting with wide QRS complex tachycardia (WCT). Decades of rigorous research have brought forth an expanding arsenal of applicable manual algorithm methods for differentiating WCTs. However, these algorithms are limited by their heavy reliance on the ECG interpreter for their proper execution. Herein, we introduce the Mayo Clinic ventricular tachycardia calculator (MC‐VTcalc) as a novel generalizable, accurate, and easy‐to‐use means to estimate VT probability independent of ECG interpreter competency. The MC‐VTcalc, through the use of web‐based and mobile device platforms, only requires the entry of computerized measurements (i.e., QRS duration, QRS axis, and T‐wave axis) that are routinely displayed on standard 12‐lead ECG recordings.

BACKGROUND: The outcomes of catheter ablation for atrial fibrillation in adults with congenital heart disease are not well described. METHODS: In a retrospective study of adult patients with congenital heart disease who underwent catheter ablation for atrial fibrillation between 2000 and 2020 at Mayo Clinic, procedural characteristics and outcomes were collected. The primary outcomes were atrial arrhythmia (AA) recurrence following a 3-month blanking period and repeat ablation. An arrhythmia clinical severity score was assessed pre- and post-ablation based on the duration of arrhythmia episodes, symptoms, cardioversion frequency, and antiarrhythmic drug use. RESULTS: One hundred forty-five patients (age, 57±12 years; 28% female; 63% paroxysmal atrial fibrillation) underwent 198 ablations with a median follow-up of 26 months (interquartile range, 14–69). One hundred ten, 26, and 9 patients had simple, moderate, and complex congenital heart disease, respectively. All patients underwent pulmonary vein isolation, and non–pulmonary vein targets were ablated in 79 (54%). AA recurrence at 12 months was 37% (95% CI, 29%–45%). On univariate analysis, increasing left atrial volume index was associated with higher odds of AA recurrence (odds ratio, 1.03 [1.00–1.06] per 1 mL/m 2 increment; P =0.05). Noninducibility of atrial flutter was predictive of decreased odds of AA recurrence (odds ratio, 0.43 [0.21–0.90]; P =0.03). A second ablation was performed in 43 patients after a median of 20 (interquartile range, 8–37) months. Arrhythmia clinical severity scores improved following ablation, reflecting a decrease in symptoms, cardioversions, and antiarrhythmic drugs. CONCLUSIONS: Catheter ablation of atrial fibrillation is feasible and effective in patients with adult congenital heart disease and reduces symptoms. Recurrence of AA frequently requires repeat ablation.

AbstractOutflow tract ventricular arrhythmias are the most common type of idiopathic ventricular arrhythmia. A systematic understanding of the outflow tract anatomy improves procedural efficacy and enables electrophysiologists to anticipate and prevent complications. This review emphasizes the three‐dimensional spatial relationships between the ventricular outflow tracts using seven anatomical principles. In turn, each principle is elaborated on from a clinical perspective relevant for the practicing electrophysiologist. The developmental anatomy of the outflow tracts is also discussed and reinforced with a clinical case.

Background : Modulation of the cardiac autonomic nervous system (ANS) is a promising adjuvant therapy in the treatment of atrial fibrillation (AF). In pre-clinical models, pulsed field (PF) energy has the advantage of selectively ablating the epicardial ganglionated plexi (GP) that govern the ANS. Objective: This study aims to demonstrate the feasibility and safety of epicardial ablation of the GPs with PF during cardiac surgery with a primary efficacy outcome of prolongation of the atrial effective refractory period (AERP). Methods : In a single-arm, prospective analysis, patients with or without a history of AF underwent epicardial GP ablation with PF during coronary artery bypass grafting (CABG). AERP was determined immediately pre- and post- GP ablation to assess cardiac ANS function. Holter monitors were performed to determine rhythm status and Heart Rate Variability (HRV) at baseline and at 1 month post-procedure. Conclusions : This study demonstrates the safety and feasibility of epicardial ablation of the GP using PF to modulate the ANS during cardiac surgery. Large, randomized analyses are necessary to determine whether epicardial PF ablation can offer a meaningful impact on the cardiac ANS and reduce AF. Results : Of 24 patients, 23 (96%) received the full ablation protocol. No device-related adverse effects were noted. GP ablation resulted in a 20.7% ± 19.9% extension in AERP (P < 0.001). Post-operative AF was observed in 7 (29%) patients. Holter monitoring demonstrated an increase in mean heart rate (74.0±8.7 vs 80.6±12.3, P=0.01). There were no significant changes in HRV. There were no study-related complications.

Background: Atypical Atrial Flutter (AAFL) prevalence is increasing due to the escalating Atrial Fibrillation (AF) ablations and cardiac surgeries. We wanted to explore the outcome of the AAFL ablation, considering the recent changes in mapping and ablation. Methods: This study was approved by the Institutional Review Board (IRB) of Mayo Clinic hospital. We retrospectively studied 419 patients who had undergone AAFL ablation at Mayo Clinic from January 2017 to June 2022. Thirteen patients declined research authorization, and 19 patients were lost to follow-up during the 90-day blanking period, resulting in a sample size of 387. The median follow-up time for patients was 25.7 months (95% CI 23.7, 32.3). Results: Recurrent symptoms with documentation of atrial arrhythmia Occurred in 226/387 (58.4%) patients, of which 151/226 (66.8%) occurred within the first year. The median time to recurrence was 8.5 months (max 57.8 months). Eleven patients died during the study period, 9 of whom experienced recurrence prior to death. Overall, the median recurrence-free survival (RFS) time was 16.6 months (95% CI 13.2, 20.0) with a 1-year RFS rate of 57.2% (95% CI 52.2, 62.7%). Acute termination occurred 324/387 (83.7%) during the ablation. The 1-year RFS rate was 58.9% (95% CI 53.5%, 64.9%) for patients with acute termination and 49.0% (95% CI 37.9%, 63.4%) for those without acute termination. The rate was not significantly different based on acute termination status (p = 0.11). Conclusions: The one-year RFS rate of 57.2% following AAFL ablation, even though 83.7% achieved acute termination during the procedure, signifies the extent of the underlying substrate abnormalities.