Heart rhythm最新文献

Background: In ventricular arrhythmia ablation procedures, traditional voltage mapping calculates overall peak-to-peak measurements. However, this methodology incorporates multiple signal components that do not distinguish near-field vs far-field components.

Objective: This study aimed to determine how the use of local bipolar measurements as identified by the first derivative of voltage over time (dV/dT) affects traditional voltage mapping characteristics.

Methods: Percutaneous endocardial and epicardial electroanatomic mapping was performed in a porcine myocardial infarction model (n = 5) with a multipolar and a point-by-point catheter. Electrograms were examined offline based on standard bipolar and unipolar voltage values and then reanalyzed by a novel algorithm that measures only the voltage magnitude pertaining to the maximum absolute dV/dT within a given electrogram. Computed tomography, gross pathology, and histopathology features were examined.

Results: There were 25,114 bipolar mapping points across multipolar catheter maps and 6317 mapping points across point-by-point catheter maps. A difference in calculated voltage occurred in >80% of all mapping points, with all changes using dV/dT methodology resulting in lower bipolar voltage values compared with traditional methods. There was a categorical change in standard voltage (scar, border zone, normal) in >7% of all points. Unipolar voltage calculated by local dV/dT also resulted in a lower value in >90% of all mapping points. Histologic examination of discrepant regions revealed patterns of diffuse fibrosis.

Conclusion: In a porcine infarct model, the use of dV/dT to identify bipolar voltage results in lower measured values in >80% of all mapping points compared with traditional peak-to-peak measurement. This methodology may more accurately identify local tissue properties by selection of near-field components within substrates implicated in ventricular arrhythmias.

Background: Pathogenic variations in lamin A/C (LMNA) result in a group of inherited conditions termed laminopathies. Cardiac manifestations of laminopathies include atrial and ventricular arrhythmias, atrioventricular conduction disorders, and cardiomyopathy, with or without skeletal muscle involvement. Because of rarity and previous cardiac characterization as adult onset, pediatric data are limited.

Objective: This study sought to investigate the natural history of cardiac disease in pediatric patients with pathogenic LMNA variants.

Methods: We identified patients ≤18 years with genetically confirmed pathogenic variants in LMNA observed at a single center between 2003 and 2024. Clinical phenotypes along with cardiac test results were retrospectively catalogued.

Results: We identified 12 patients with pathogenic LMNA variant with a median age of 4.9 years at diagnosis (interquartile range, 3.7-10.7 years). Of the 12 patients, 9 (75%) were male and 10 (83%) had skeletal muscle involvement. Cardiac manifestations developed in 9 patients (75%) during a median follow-up of 9.5 years (interquartile range, 7.0-13.3 years). Nine patients (75%) had conduction abnormalities or arrhythmias (atrioventricular block, ventricular/atrial tachycardias), and 4 (33%) had cardiovascular implantable electronic devices placed. Two (17%) patients were diagnosed with cardiomyopathy, 1 (8%) requiring heart transplant. Two (17%) patients died during the study.

Conclusion: Cardiac involvement, specifically cardiomyopathy and progressive conduction system abnormalities, were common in pediatric patients with pathogenic LMNA variants. Early genetic diagnosis of laminopathies with frequent surveillance for arrhythmias and cardiac dysfunction is necessary for more timely initiation of advanced therapies to prevent adverse events. More comprehensive phenotype-genotype correlation is strongly needed to better understand early cardiac manifestations in laminopathies.

Background: The results of pulmonary vein isolation (PVI) are limited by arrhythmia recurrence, which is most often due to failure to effectuate a durable contiguous circumferential transmural lesion around the pulmonary vein ostia. We postulated that enhancing the index ablation line through use of multiple cryoballoon diameters would be superior to standard ablation with bonus freeze.

Objective: XXXX.

Methods: We enrolled 226 consecutive patients referred for cryoballoon-based PVI. Patients underwent PVI either with the 28-mm Arctic Front Advance (Medtronic) cryoballoon using two 4-minute freezes (standard group) or with the POLARx FIT (Boston Scientific) cryoballoon using 3-minute freezes in both the 28- and 31-mm-diameter configurations (double stack group). Patients were followed for 1 year. The primary outcome was atrial tachyarrhythmia recurrence, with procedural complications, cardioversion, emergency department visit, hospitalization, and repeat ablation being secondary outcomes.

Results: A total of 226 patients were included (70% male; 47% with persistent atrial fibrillation [AF]). Patients in the double stack group had a significantly greater freedom from recurrent atrial tachycardia/ AF/atrial flutter at 1 year (85.1% vs 65.3%; hazard ratio 0.42; 95% confidence interval 0.25-0.74; P=.008). Periprocedural complications were similar between the groups (5.2% vs 3.4%; P=.50). At 1 year, there was no difference in cardioversion (12.8% vs 20.3%; P=.20), emergency department visit (9.0% vs 15.5%; P=.22), or all-cause hospitalization (1.3% vs 2.7%; P=.66). Significantly less patients treated with double stack underwent repeat ablation (1.3% vs 13.5%; P=.002).

Conclusion: In a mixed cohort of patients with paroxysmal and persistent AF, cryoballoon ablation using the double stack technique is associated with lower rates of AF recurrence and lower rates of repeat ablation.

The main function of the implantable cardioverter-defibrillator (ICD) is to protect against sudden cardiac death (SCD) due to ventricular tachyarrhythmia (VTA). Current guidelines provide a recommendation to implant a prophylactic ICD for the primary prevention of SCD in individuals having heart failure with reduced ejection fraction (HFrEF) who never experienced a previous sustained VTA. However, these recommendations are based on clinical trials conducted more than 20 years ago and may not be applicable to contemporary patients with HFrEF who have a lower arrhythmic risk as a result of advances in heart failure medical therapies. Thus, there is an unmet need for more appropriate selection of contemporary patients with HFrEF for a primary prevention ICD. In this article, we review data underlying the current clinical equipoise on the need for routine implantation of a primary prevention ICD in patients with HFrEF and the rationale for conducting clinical trials that aim to reassess the role of the ICD in this population.

Background: Detecting atrial fibrillation (AF) after stroke is a key component of secondary prevention, but indiscriminate prolonged cardiac monitoring is costly and burdensome. Multivariable prediction models could be used to inform selection of patients.

Objective: This study aimed to determine the performance of available models for predicting AF after a stroke.

Methods: We searched for studies of multivariable models that were derived, validated, or augmented for prediction of AF in patients with a stroke, using MEDLINE and Embase from inception through September 20, 2024. Discrimination measures for tools with C statistic data from ≥3 cohorts were pooled by bayesian meta-analysis, with heterogeneity assessed through a 95% prediction interval. The risk of bias was assessed with the Prediction model Risk Of Bias Assessment tool (PROBAST).

Results: We included 75 studies with 58 prediction models; 66% had a high risk of bias. Fifteen multivariable models were eligible for meta-analysis. Three models showed excellent discrimination: SAFE (C statistic, 0.856; 95% confidence interval [CI], 0.796-0.916), SURF (0.815; 95% CI, 0.728-0.893), and iPAB (0.888; 95% CI, 0.824-0.957). Excluding high-bias studies, only SAFE showed excellent discrimination (0.856; 95% CI 0.800-0.915). No model showed excellent discrimination when limited to external validation or studies with ≥100 AF events. No clinical impact studies were found.

Conclusion: Three of the 58 identified multivariable prediction models for AF after stroke demonstrated excellent statistical performance on meta-analysis. However, prospective validation is required to understand the effectiveness of these models in clinical practice before they can be recommended for inclusion in clinical guidelines.

Background: Catheter ablation is an effective treatment of atrial fibrillation. Pulsed field ablation (PFA) has emerged as a novel energy modality that relies on high-voltage electric fields to achieve cardiac tissue ablation. Data on its efficacy in the elderly are scarce.

Objective: This study aimed to evaluate the procedural details and clinical outcomes of PFA in patients >75 years old.

Methods: Consecutive patients with atrial fibrillation >75 years old undergoing PFA with the Farapulse system were enrolled at 6 high-volume centers. Procedural details and clinical outcomes were compared with those of patients undergoing second-generation cryoballoon ablation (CBA) and radiofrequency ablation (RFA).

Results: Of 983 patients, 221 underwent PFA, 216 CBA, and 546 RFA. Procedure times were shorter with PFA (72 ± 30 minutes) compared with CBA (77 ± 27 minutes) and RFA (99 ± 23 minutes; P < .001). Extra-pulmonary vein ablation was performed in 74.2% PFA, 9.7% CBA, and 42.1% RFA (P < .001). The major complication rate was 1.01% (n = 10) and was not significantly different between groups (1 PFA, 2 CBA, and 7 RFA; P = .578). Minor complications were observed in 1.4% PFA, 5.1% CBA, and 3.5% RFA (P = .093). The 1-year atrial tachyarrhythmia freedom in the propensity score-matched population was 77.2% with PFA, 80.8% with CBA, and 74.9% with RFA; P = .52).

Conclusion: PFA is a safe and effective option for elderly patients, offering the advantage of enabling extra-pulmonary vein ablation without the concern of thermal injury risk.

Pulsed-field ablation (PFA) offers notable advantages in atrial fibrillation (AF) ablation by selectively targeting cardiomyocytes via an irreversible electroporation mechanism, thereby minimizing damage to surrounding tissues. Although clinical studies demonstrate that PFA is both safe and effective, PFA-mediated hemolysis and potential acute kidney injury (AKI) have been recently reported. This study comprehensively reviews the literature on PFA-associated hemolysis, analyzing the underlying mechanisms, risk factors, and preventive management strategies. In addition, the review discusses approaches to minimize the risk of PFA-induced hemolysis and AKI while offering insights for improving PFA-associated techniques.