JACC. Clinical electrophysiology最新文献

Background: The implantable cardioverter-defibrillator (ICD) is recognized as the most effective life-saving therapy in patients with Brugada syndrome (BrS). However, transvenous ICD is associated with a notable rate of complications over time. The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as a promising alternative to the transvenous ICD. Nevertheless, long-term data from large cohorts of BrS patients with S-ICDs are lacking.

Objectives: This multicenter study aimed to assess the long-term outcomes of S-ICD therapy in patients with BrS.

Methods: The study included 450 consecutive BrS patients (mean age 43 ± 12; 86% male) who underwent S-ICD implantation between 2014 and 2024.

Results: During a median follow-up of 52 months (25th-75th percentile: 29-72), appropriate shocks were delivered in 3% of patients (1.2%; 95% CI: 0.2-2.2, at 12 months), with a first-shock success rate of 90% (100% with 2 shocks). Inappropriate shocks occurred in 7% of patients (1.4%; 95% CI: 0.3-2.5, at 12 months). Shock zone programmed at 250 beats/min (HR: 0.40; 95% CI: 0.18-0.89; P = 0.025) and more than 1 suitable vector on screening (HR: 0.39; 95% CI: 0.17-0.87; P = 0.023) were independent protective factors against inappropriate shock. Device-related complications were reported in 4% of patients (2.5%; 95% CI: 1.0-3.9 at 12 months). The need for antibradycardia pacing was reported in 3 patients (0.7%). No device explantation because of the need for antitachycardia pacing was noted.

Conclusions: Our findings support the S-ICD as a viable alternative to the transvenous ICD for preventing sudden cardiac death in BrS patients without pacing indication (Arrhythmias Detection in a Real World Population [RHYTHM DETECT]; NCT02275637).

Background: Septal perforation, defined as partial or complete protrusion of a lead helix, is a potential complication of left bundle branch area pacing, theoretically increasing risks of pacing failure and thromboembolism. However, no studies have examined the long-term prognosis of patients with partial perforations (PPs).

Objectives: This study aimed to elucidate the incidence, outcomes, and electrophysiological characteristics of PP in clinical and experimental swine studies.

Methods: Patients requiring pacing who underwent successful left bundle branch area pacing were retrospectively included. PP was identified using postoperative echocardiography. Clinical outcomes, including all-cause mortality, thromboembolism, and lead-related complications, were compared between the PP and non-PP groups. Waveforms from the nonfiltered unipolar electrogram (NF-EGM) recorded at the lead tip were evaluated to identify morphology specific to PP.

Results: Of the 95 patients, PP was confirmed in 25 (26.3%), occurring only in patients with left bundle branch capture, with an incidence rate of 41.7%. Event-free survival rates were comparable between the PP and non-PP groups at a median follow-up of 24 months (log rank, P = 0.298). No thromboembolisms or lead-related complications occurred in the PP group. The type-QS and type-R morphologies of NF-EGM reliably identified and excluded PP, respectively, as validated in swine heart experiments.

Conclusions: This study found that PP is not associated with an increased risk of adverse clinical outcomes. Deep septal lead deployment utilizing the NF-EGM morphology would be useful in recognizing and avoiding PP intraoperatively.

Background: The pentaspline pulsed field ablation (PFA) catheter is rapidly gaining popularity as a tool for pulmonary vein isolation (PVI). Its standard ablation protocol recommends applying 8 applications per pulmonary vein (PV) with 2 different catheter configurations: the flower and the basket shape. Using this protocol, the rate of durably isolated PVs during repeat procedures is not superior to that after conventional thermal PVI.

Objectives: This study aimed to improve PVI durability with the pentaspline PFA catheter through an extension of the ablation protocol and the introduction of a novel catheter shape.

Methods: We added 2 applications in a small olive-shaped catheter configuration, leading to a total of 10 applications per PV. Procedural data, safety data, and remapping data from patients undergoing repeat procedures and clinical outcomes were analyzed.

Results: A total of 400 consecutive patients were treated with the new olive strategy. In patients undergoing repeat procedures, PV reconnection was significantly less frequent after PVI with the olive strategy (13.6% [3 of 22 patients]) than after the conventional strategy (45% [36 of 80 patients]; P = 0.007). Procedure-related complications occurred in 11 (2.75%) of 400 patients. Comparison of 100 patients treated with the olive strategy vs 100 propensity score-matched conventional patients found no difference in freedom of arrhythmia at 180 days after the procedure (olive strategy: 86%; conventional strategy: 87.3%; P = 0.75).

Conclusions: We report on the initial clinical experience of a novel ablation protocol for PVI with the pentaspline PFA catheter. The Olive Strategy is safe to use and significantly improves PVI durability.

Background: Brugada syndrome (BrS) continues to pose clinical challenges, despite 3 decades of dedicated research and therapeutic advancements. The pivotal role of implantable cardioverter-defibrillator (ICD) therapy in safeguarding high-risk BrS patients from sudden cardiac death due to ventricular arrhythmias is undeniable. However, the debate on risk stratification and the use of ICDs for primary prevention remains ongoing.

Objectives: This study aimed to evaluate the clinical features, management, and long-term outcomes of ICD therapy in patients with Brugada syndrome.

Methods: BrS-diagnosed patients were prospectively enrolled. Inclusion criteria were: 1) a Brugada type 1 electrocardiogram pattern, either spontaneous or drug induced; 2) ICD implantation; and 3) consistent follow-up. Risk stratification was based on prior arrhythmic events, and the multiparametric Brussel risk score was used from 2017. High-risk patients underwent video-thoracoscopic epicardial ablation starting in 2016. ICD implantation strategies evolved over time, guided by patients' clinical and demographic characteristics.

Results: A total of 306 consecutive Brugada patients (186 male [61%]; mean age 41 ± 17 years; range: 1-82 years) received ICDs at our institution from 1992 to 2022. ICDs were implanted for secondary prevention in 16% of patients. Over the 3 decades, the proportions of secondary prevention implants and asymptomatic patients remained stable, while risk factors fluctuated in the first two decades before stabilizing. During long-term follow-up (median 103 months [63-147 months]), 14% of patients experienced at least 1 sustained ventricular arrhythmia (VA) (1.59 per 100 person-years), 15% had at least 1 inappropriate ICD shock-unaffected by the presence of single or dual leads-and 27% required device revision and/or lead replacement. Patients with secondary prevention ICDs had a higher incidence of both ventricular and supraventricular arrhythmias compared to those with primary prevention ICDs. Loss-of-function mutations and prior nonsustained VAs were associated with sustained VAs. Among high-risk patients, those who underwent epicardial ablation experienced significantly fewer ventricular events. The overall mortality rate was 5.88%, with 22.2% of deaths attributed to cardiac causes.

Conclusions: This 30-year study highlights ICD therapy's critical role in preventing fatal arrhythmias in Brugada syndrome, but also reveals frequent device-related complications, especially in younger patients. Thoracoscopic epicardial ablation significantly reduced VA in high-risk patients, offering a promising adjunctive therapy. These findings emphasize the need for individualized treatment strategies to balance the benefits of ICDs with their risks, and underscore the potential of ablation to improve long-term outcomes.

Background: There is an emerging interest in artificial intelligence-enhanced 12-lead electrocardiogram (AI-ECG) in detection of hypertrophic cardiomyopathy (HCM).

Objectives: This study describes the initial real-world experience of using AI-ECG (Viz-HCM, developed using a convolutional neural network trained algorithm) in our center.

Methods: All patients undergoing 12-lead electrocardiograms at Cleveland Clinic, Cleveland, Ohio, between February 19, 2024, and November 1, 2024, were prospectively analyzed for potential HCM using AI-ECG. The numbers of patients flagged for potential HCM were recorded. Presence of confirmed HCM, a new diagnosis of HCM following AI-ECG assessment (with a negative prior clinical evaluation), and alternative non-HCM diagnosis were recorded. Assessment of AI-ECG diagnostic performance was done using various HCM probability thresholds (≥0.95, ≥0.90, and ≥0.85).

Results: Of 103,492 electrocardiograms analyzed in 45,873 patients, AI-ECG flagged potential HCM in 1,265 (2.7%) unique patients. Of these, 511 (40.4%) had confirmed HCM, 63 (5%) had new HCM diagnosis, and 691 (54.6%) had an alternate diagnosis. HCM probability threshold of ≥0.85 provided the highest sensitivity (95%) for diagnosis of HCM with high specificity and accuracy (all >98%). The positive predictive value was the highest (66%) at the cutoff ≥0.95 but with a lower sensitivity at 50%. The AI-ECG algorithm performed similarly in both men and women, and was more sensitive in individuals <50 years but more specific in individuals ≥50 years.

Conclusions: Prospective real-world application of the AI-ECG algorithm to detect HCM was associated with a high degree of accuracy, varying with the chosen probability threshold. It also enabled the identification of 5% of patients with no prior HCM diagnosis.

Background: Limited data exist on reducing the atrial fibrillation (AF) burden, the regression from persistent to paroxysmal AF, and symptom improvement after cryoablation in patients with persistent AF.

Objectives: This study sought to evaluate the efficacy of cryoablation in reducing the AF burden, regression to paroxysmal AF, and symptom improvement in patients with early persistent AF.

Methods: This investigator-initiated, multicenter, and prospective cohort study enrolled the patients with early persistent AF (≤3 years). All patients were inserted an implantable loop recorder at the time of trial entry. AF burden (percentage of time in AF) and actual AF type were evaluated during pre-cryoablation and 12-month follow-up after cryoablation. AF-related symptoms and quality of life were assessed.

Results: A total of 130 patients were enrolled (median age 61 years [Q1-Q3: 54-67 years]; median duration of persistent AF 6 months [Q1-Q3: 4-10 months]). The mean AF burden before cryoablation was 77 ± 34% (25.4% of high-burden paroxysmal AF; 74.6% of implantable loop recorder-confirmed persistent AF), which was reduced to 9 ± 21% after 12-month follow-up (mean 68 ± 37% of AF burden reduction; P < 0.001). Of the total, 38.5% had no recurrence of AF, 43.1% had a recurrence of paroxysmal AF, and 18.5% had a recurrence of persistent AF. Among those with confirmed persistent AF at baseline, 76% of patients showed regression to paroxysmal AF or no recurrence. After cryoablation, 77% of patients improved AF-related symptoms and quality of life as assessed by 36-Item Short Form Survey questionnaires.

Conclusions: In patients with early persistent AF, cryoablation significantly reduced AF burden and achieved regression of AF type followed by symptom improvement. (Cryoablation for Pulmonary Vein Isolation Alone in Patients with Early Persistent AF Assessed by Continuous Monitoring [COOL-PER]; NCT05507749).

Background: There is an ongoing effort to develop catheters with closer interelectrode spacing to improve mapping resolution. However, the optimal distance for mapping postinfarct scar has yet to be established.

Objectives: This study sought to assess the effect of interelectrode distance on ventricular scar electrograms.

Methods: In 8 swine with healed myocardial infarction, the left ventricle was mapped using an experimental 48-electrode array with a 1.2 mm center-to-center distance. Additional maps with 2.4, 3.6, and 4.8 mm distances were created using nonadjacent electrodes. The impact of interelectrode distance on voltage amplitude and near-field (NF) and far-field (FF) activity relationships was analyzed.

Results: At a 1.2 mm interelectrode distance, voltage amplitudes <1.5 mV accurately correlated with the endocardial infarct surface area, while increasing the distance to 4.8 mm progressively overestimated the infarct area (P < 0.001). However, adjusting voltage cutoffs for each interelectrode distance restored the correlation to the actual infarct size. The primary distinction between distances was the ability to differentiate NF from FF potentials. At 4.8 mm and 3.6 mm, FF potential amplitude often exceeded NF amplitude (NF/FF ratios of 0.8 ± 0.3 and 0.9 ± 0.2, respectively). Reducing the distance to 2.4 mm attenuated FF potentials, yielding an NF/FF ratio of 1.2 ± 0.4. Further reduction to 1.2 mm showed no significant additional effect (NF/FF ratio 1.3 ± 0.3; P = 0.09).

Conclusions: Bipoles with a 2 mm interelectrode distance most effectively match endocardial scar tissue and attenuate NF potentials. These benefits plateau at 2 mm, suggesting that it may represent the optimal distance for delineating postinfarction substrates.