JACC. Clinical electrophysiology最新文献

Background: Pacemakers and implantable cardioverter-defibrillators in pediatric and congenital heart disease (CHD) patients may be required for decades. In this population, there are sparse data on long-term lead functionality.

Objectives: The aims of this study were to assess pacemaker and defibrillator lead survival in pediatric and CHD patients beyond 10 years after implantation and to identify patient- and lead-related factors associated with earlier lead failure.

Methods: This was a retrospective study reviewing all patients with a pacemaker or defibrillator who received care at a single large children's hospital during a 30-year timespan. The log-rank test and Cox proportional hazards model were used to identify risk factors associated with earlier lead failure.

Results: Data were collected from 952 leads in 396 patients. Overall lead survival was 87% at 10 years, 78% at 15 years, and 69% at 20 years. Male sex, younger patient age, greater somatic growth, left ventricular lead location, and epicardial implantation approach were associated with higher likelihood of lead failure (log-rank test P <0.05). On multivariate analysis, the most significant predictor of lead failure was patient somatic growth ≥5 cm/year (HR 3.33; 95% CI: 1.78-6.25). The presence of CHD, lead insulation, and lead manufacturer had no impact on lead longevity.

Conclusions: Greater patient somatic growth is an important predictor of lead failure. Greater somatic growth may account for the observation in this study (and prior studies) that leads in male patients, younger patients, and implanted via epicardial approach were more likely to fail.

Background: The elderly population with atrial fibrillation (AF) is growing. There is limited evidence to suggest AF ablation as an effective treatment for the elderly.

Objectives: This study aimed to investigate the temporal trends of first-time ablations in the elderly, the impact of age on major adverse cardiovascular events (MACE), and a composite endpoint of AF-related hospitalizations, repeat AF ablation, or use of antiarrhythmic drugs (AADs).

Methods: Utilizing the Danish administrative registers, we incorporated individuals undergoing their first-time AF ablation from 2001 to 2020. Our cohort was divided into 3 age groups (<60, 60-74, and ≥75 years) and scrutinized across 4 consecutive 5-year intervals. Cox proportional-hazard multivariable analyses and cumulative incidences were used to evaluate the endpoints of 5-year MACE incidence and a 1-year composite endpoint of AF-related hospitalizations, repeat AF ablation, or use of antiarrhythmic drugs.

Results: Elderly patients who underwent AF ablation increased significantly, from none in 2001 to 9% in 2020. The 5-year incidence of MACE in the elderly decreased from 61.9% (95% CI: 41.1%-82.7%) to 38.1% (95% CI: 31.9%-44.2%). The HR for age ≥75 years in the last time period was 1.52 (95% CI: 1.26-1.83). The 1-year composite outcome varied from 35.6% to 52.0%; age was not a consistent predictor.

Conclusions: AF ablation use in the elderly has significantly increased over time. A notable decrease in MACE was evident across all age cohorts, with a particularly pronounced trend observed among the elderly population. Age was not an independent predictor of the composite endpoint.

The left ventricular summit (LVS) is the most common site of epicardial arrhythmias. Ablation of LVS arrhythmias continue to pose a challenge to the electrophysiologist because of its complex and intimate anatomical location. In this review, we undertake a detailed examination of the intricate anatomy of the LVS alongside a comprehensive synthesis of mapping and ablation strategies used to treat LVS arrhythmias.

Background: Cardioneuroablation (CNA) is a promising treatment for syncope.

Objectives: This study sought to analyze the success and risk of CNA ,and to describe predictive factors of CNA success in patients with syncope.

Methods: Seventy-seven consecutive patients with syncope treated with CNA in 22 hospitals and at least 6 months of follow-up were included. Patients with reflex cardioinhibitory, mixed syncope, functional sinus node dysfunction (SND), or functional atrioventricular block were included. The primary endpoint was the recurrence of syncope after the CNA.

Results: Mean age was 49.3 ± 13.4 years and 54.5% were women. Five (6.5%) patients presented complications. Three patients presented SND, 1 required a pacemaker. During a median follow-up of 12 months (Q1-Q3: 8-20 months), 26 (33.8%) patients had recurrence of syncope. Women had a significantly higher risk of recurrence compared with men (HR: 3.3; 95% CI: 1.2-8.8; P = 0.016). Patients >50 years of age had a significantly lower risk of recurrence compared with younger patients (HR: 0.3; 95% CI: 0.1-0.9; P = 0.032). The risk of recurrence in mixed syncope was significantly higher than in cardioinhibitory syncope (HR: 4.4; 95% CI: 1.1-17.5; P = 0.033). Syncope recurrence was significantly less frequent in patients treated with general anesthesia or deep sedation compared with conscious sedation (HR: 0.2; 95% CI: 0.1-0.6; P = 0.002). Finally, the number of radiofrequency applications (≤30 or >30) had a significant association with CNA success (HR: 0.4; 95% CI: 0.2-0.9; P = 0.042). These results were adjusted for confounding factors.

Conclusions: In this multicenter study, the effectiveness of CNA was less than previously reported. We found a 3.9% risk of SND. Male sex, age >50 years, cardioinhibitory syncope, general anesthesia or deep sedation, and >30 radiofrequency applications could predict success of CNA for syncope.

Background: The long-term natural history of autonomic alterations following catheter ablation of drug-refractory paroxysmal atrial fibrillation is poorly defined.

Objectives: The authors sought to define the long-term impact of thermal catheter ablation on the cardiac autonomic system.

Methods: The study included 346 patients with drug-refractory paroxysmal atrial fibrillation undergoing pulmonary vein isolation using thermal ablation energy (radiofrequency or cryoballoon ablation). All patients underwent insertion of a Reveal LINQ implantable cardiac monitor prior to ablation. The implantable cardiac monitor continuously recorded physical activity, heart rate variability (HRV) (measured as the standard deviation of the average normal-to-normal), daytime heart rate, and nighttime heart rate (NHR). Longitudinal autonomic data in the 2-month period prior to the date of ablation were compared with the 3 years following ablation.

Results: Following ablation, there was a significant decrease in HRV (10-20 ms; P < 0.0001) and significant increases in daytime heart rate and NHR (10 beats/min [P < 0.0001] and 7 beats/min [P < 0.0001], respectively). Changes in autonomic parameters were greatest in the first 3 months following ablation but remained significantly different from baseline for 36 months following ablation. Greater changes in NHR and HRV were associated with improved freedom from recurrent arrhythmia. The type of thermal ablation energy had no influence on the heart rate and autonomic parameters.

Conclusions: Pulmonary vein isolation using thermal ablation energy results in significant sustained changes in the heart rate parameters related to autonomic function. These changes are independent of the ablation technology employed and are associated with procedural success. (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration [CIRCA-DOSE]; NCT01913522).

Background: We have previously shown that dyssynchronous premature atrial complexes (PACs) from the lateral left atrium (LA) lead to greater atrial mechanical dysfunction, remodeling, and sustained atrial fibrillation (AF) than synchronous PACs from the interatrial septum. However, the impact of PAC coupling interval (CI) on atrial remodeling is unclear.

Objectives: This study sought to explore the effect of PAC CI on atrial mechanics and remodeling in the swine model.

Methods: A 2-phase in vivo study was conducted. In the phase 1 acute study, 5 swine underwent acute invasive hemodynamics and echocardiography while delivering single-paced atrial extrastimuli with CIs varying from 450 ms to 200 ms. Peak LA longitudinal strain and intra-LA dyssynchrony were assessed with 2-dimensional strain echocardiography while LA and aortic pressure were directly measured. In the phase 2 chronic study, a group exposed to paced bigeminy from the lateral LA for 16 weeks with a short CI of 250 ms (Short-PAC, n = 10) was compared with groups with PACs at a long CI of 400 ms (Long-PAC, n = 5) and a nonpaced control group (CTRL, n = 10). Detailed electrophysiology and echocardiography studies were performed with histologic quantification of LA fibrosis at baseline and prior to sacrifice.

Results: Phase 1 revealed that as PAC CI shortened, peak LA strain decreased (P = 0.003) and LA dyssynchrony increased (P < 0.001). Phase 2 showed that after 16 weeks of PACs, the Short-PAC group had greater LA dilation (terminal baseline: 5.9 ± 1.2 cm² vs Long-PAC 3.9 ± 0.5 cm² vs CTRL 0.9 ± 0.4 cm²; P < 0.001) and reduced peak LA strain during sinus rhythm (terminal baseline: -17.3 ± 3.2% vs Long-PAC -12.1 ± 2.1% vs CTRL -0.7 ± 4.2%; P < 0.001). The short-PAC group had a more LA fibrosis (8.6 ± 1.0% vs Long-PAC 6.8 ± 1.0% vs CTRL 4.0 ± 1.5%; P < 0.001) and higher AF inducibility (terminal baseline: 49.3 ± 13.0% vs Long-PAC 29.0 ± 6.4% vs CTRL 2.2 ± 16.2%; P < 0.001) than the other groups.

Conclusions: In this swine model, shorter PAC CI led to increased acute atrial mechanical dysfunction and dyssynchrony. Chronically, short-CI PACs led to greater atrial fibrosis and induced AF, suggesting that frequent, short-coupled PACs pose the highest risk for LA myopathy and AF. These insights underscore the importance of understanding the impact of PAC characteristics on atrial remodeling and arrhythmogenesis.

Catheter ablation to prevent ventricular tachycardia (VT) that emerges late after a myocardial infarction aims to interrupt the re-entry substrate. Interruption of potential channels and regions of slow conduction that can be identified during stable sinus or paced rhythm is often effective and a number of substrate markers for guiding this approach have been described. While there is substantial agreement with different markers in some patients, the different markers select different regions for ablation in others. Mapping during VT to identify critical re-entry circuit isthmuses is likely more specific, and most useful when VT is incessant or frequent during the procedure or when sinus rhythm substrate ablation fails. Both approaches are often combined. These methods for identifying and characterizing post-infarct-related arrhythmia substrate and the re-entry circuits are reviewed.