Journal of Innovations in Cardiac Rhythm Management最新文献

Conduction system pacing has emerged as a new pacing technique to achieve cardiac physiologic pacing, but its utility and safety in patients with atrial fibrillation undergoing simultaneous ablation of the atrioventricular node remains seemingly unknown. Here, we present a case series of 10 patients with long-standing persistent or permanent atrial fibrillation who failed rate-control therapy and elected to proceed with simultaneous ablation of the atrioventricular node and His-bundle pacemaker implantation.

Hypertrophic cardiomyopathy (HCM) is an inherited disease present in 1 in 500 individuals and is the most common cause of sudden cardiac death in children. We present the case of a 17-year-old boy with HCM and a primary prevention subcutaneous implantable cardioverter-defibrillator (S-ICD) who developed left ventricular outflow tract obstruction and a myocardial bridge of the left anterior descending coronary artery. The patient underwent a septal myectomy/myotomy and muscular bridge unroofing. The S-ICD system was undisturbed during the surgery, with no loss of function. Septal myectomy may be accomplished in pediatric HCM patients following optimal S-ICD placement with maintained S-ICD function.

Ventricular tachycardia (VT) is a life-threatening arrhythmia associated with high morbidity and mortality, particularly in patients with structural heart disease. Radiofrequency ablation is an effective procedure to treat patients with this malignant arrhythmia. We report three cases of successful termination of VT using unique catheter ablation techniques. Through these cases and techniques, we highlight the advantages of specific localization of abnormal circuits within the cardiac layer involved, as well as electrogram evidence of tachycardia termination.

Right atrial tachycardia (AT) is a frequent rhythm disorder in patients with atrial scar mainly due to surgical incisions or congenital heart diseases. Despite the mounting evidence about AT mechanisms and types, data are scarce regarding the conduction properties as well as the functional characteristics of the atrial substrate during sinus rhythm, which plays a role in the maintenance of tachycardia. We sought to evaluate the relationship between the functional substrate mapping (FSM) characteristics of the right atrium (RA) and the critical isthmus (CI) of re-entrant ATs in patients with underlying atrial scar. Patients with a history of right AT who underwent catheter ablation with three-dimensional mapping were retrospectively enrolled. A voltage map and isochronal late activation map were created during the sinus/paced rhythm using multielectrode catheters to detect deceleration zones (DZs). Subsequently, AT was induced with programmed stimulation, and activation mapping was performed to detect the CI of the tachycardia. Atrial tachyarrhythmia (ATa) recurrence was defined as the detection of atrial fibrillation or AT (≥30 s) during follow-up. A total of 24 patients (mean age, 46 ± 15 years; 13 [54%] women) with right AT were included. A total of 36 ATs were mapped (16 [44.4%] localized re-entry, 20 [55.6%] macro-re-entry). Atrial low-voltage zones composed 23.3% ± 13.0% of the total RA. The mean values of bipolar voltage, electrogram duration, and conduction velocity during sinus rhythm corresponding to the CI of ATs were 0.18 ± 0.10 mV, 121.7 ± 29.4 ms, and 0.06 ± 0.04 m/s, respectively. The total number of DZs per chamber was 1.1 ± 0.3, with all being located in the low-voltage zone (<0.5 mV) detected by high-density mapping. All CIs of non-cavotricuspid isthmus (CTI)-dependent re-entry were co-localized with DZs detected during FSM. The positive predictive value of DZs to detect the CI of inducible ATs was 80.8%. During a mean follow-up of 11.7 ± 8.1 months, freedom from atrial tachyarrhythmias was 87.5%. Although CTI-dependent macro-re-entry is the most common mechanism in patients with RA scar, our findings demonstrated the relevance of FSM to predict non-CTI-dependent ATs. Conduction slowing manifested as DZs with continuous-fragmented signal morphology may guide ablation strategy tailoring in the case of underlying RA scar.

Atrial fibrillation (AF) is a major sequela after bioprosthetic valve replacement (BPVR) in patients with valvular heart disease. This study evaluates the data compiled from different meta-analyses in an umbrella review. We investigated the anticoagulation efficacy of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) in patients with AF and BPVR. A comprehensive search of the Cochrane Database of Systematic Reviews, EMBASE, and PubMed was completed to find papers published up until June 2024 that could be included in this umbrella review. Randomized controlled trials (RCTs) and retrospective observational/cohort studies were primarily identified as the foundation of meta-analyses and peer-reviewed systematic reviews. The quality of the included publications was determined using the AMSTAR 2 tool and the Cochrane Collaboration's risk-of-bias tool, while the overall certainty of the evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. A total of 20 systematic reviews and meta-analyses of RCTs and observational studies were included in this umbrella review. Among the primary outcomes, the pooled analysis exhibited a significant reduction in all-cause mortality (risk ratio [RR], 0.95; 95% confidence interval [CI], 0.91-1.00; P = .05; I2 = 0%), risk of major/life-threatening bleeding (RR, 0.73; 95% CI, 0.66-0.82; P ≤ .00001; I2 = 66%), and stroke/thromboembolism (RR, 0.74; 95% CI, 0.67-0.82; P = .00001; I2 = 0%) in patients who were administered DOAC pharmacotherapy as compared to VKAs. The only primary outcome that demonstrated clinically insignificant results was all-cause stroke (RR, 0.9; 95% CI, 0.79-1.04; P = .16; I2 = 54%). Secondary outcomes such as intracranial bleeding, any bleeding, and minor or clinically insignificant bleeding all showed a significantly decreased risk in the DOAC group versus the VKA group. Only two outcomes revealed an increased risk of cardiovascular events and risk of ischemic stroke in patients who received DOACs; however, these outcomes were statistically insignificant. According to our analysis, DOACs exhibit a superior safety and efficacy profile to that of VKAs when it comes to treating patients with BPVR. DOACs do not require continuous monitoring; therefore, they could be an effective substitute for VKAs in these individuals.

Left bundle branch area pacing (LBBAP) may mitigate pacing-induced cardiomyopathy (PICM) and is increasingly favored over traditional right ventricular pacing (RVP). We sought to evaluate the impact of a practice-wide switch from RVP to LBBAP. We switched practice from RVP to primarily LBBAP at our center in 2020. A retrospective review was conducted to compare patients who underwent LBBAP from 2020-2023 with controls who underwent RVP from 2018-2019. The LBBAP (n = 288; age, 73.3 ± 10.7 years; left ventricular ejection fraction [LVEF], 56.9% ± 11.4%) and RVP (n = 172) groups were similar in terms of age, body mass index, hypertension, diabetes, and LVEF. The LBBAP group as compared to the RVP group had fewer women (38% vs. 51%; P = .006) and longer intrinsic conducted QRS durations (117 ± 28 vs. 110 ± 30 ms; P = .04). LBBAP devices required longer implant (102 vs. 67 min) and fluoroscopy (9.3 vs. 6.9 min) times but resulted in shorter paced QRS durations (122 ± 20 vs. 145 ± 24 ms; all P < .0001). At 3 months, LBBAP patients had higher sensing (13.8 ± 6.1 vs. 12.0 ± 5.6 mV; P = .007), lower pacing impedance (543 ± 98 vs. 576 ± 150 Ω; P = .008), and similar capture threshold (0.78 ± 0.24 vs. 0.76 ± 0.35 V; P = .5) values. Device-related adverse events were similar between the groups (LBBAP 8.7% vs. RVP 8.8%; P = 1.0), which included ventricular lead dislodgement (2.1% vs. 0.6%; P = .3). There were no differences in hazard rates of all-cause mortality (P = .5) or heart failure (HF) hospitalizations (P = .07). In a subgroup of patients with ≥20% ventricular pacing, the average LVEF change during follow-up in the LBBAP group as opposed to the RVP group was +1.6% ± 12.9% versus -3.8% ± 12.0% (P = .03), the average left ventricular internal diameter at end-diastole change was -0.18 ± 0.73 cm versus +0.16 ± 0.45 cm (P = .006), and there were no differences in the hazard rate of all-cause mortality (P = .6) or HF hospitalizations (P = 1.0). Our results suggest there were no adverse consequences of the practice-wide switch from RVP to LBBAP. LBBAP was associated with longer procedure and fluoroscopy times but resulted in narrower paced QRS durations and less PICM.

Atrial fibrillation (AF) ablation is a common treatment for symptomatic AF. Remote magnetic navigation (RMN) and manual catheter navigation (MCN) are two predominant techniques employed in this procedure, each with advantages and limitations. This meta-analysis compares the efficacy, safety, and procedural outcomes of RMN versus MCN for AF ablation. A comprehensive search was conducted across PubMed, Google Scholar, and Embase to identify relevant studies comparing RMN and MCN for AF ablation. Statistical pooling was done using Review Manager 5.4.1 (Cochrane Collaboration, London, UK). The Newcastle-Ottawa scale was used for the evaluation of bias in observational studies. We evaluated the robustness of the evidence following the guidelines outlined by the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) working group. The primary outcomes of the study included freedom from AF, procedure time, fluoroscopy time, and total complication rate in patients undergoing AF ablation either using the RMN or MCN technique. A total of 22 studies involving 5361 patients were included in the meta-analysis. The pooled analysis demonstrated comparable freedom from AF between RMN and MCN (relative risk [RR], 0.94; 95% confidence interval [CI], 0.84-1.04; P = .23). However, RMN was associated with a significantly prolonged procedure duration (mean difference [MD], 48.58; 95% CI, 31.49-65.66; P < .00001) and reduced fluoroscopy time (MD, -12.52; 95% CI, -17.84 to -7.20; P < .00001) compared to MCN. Additionally, RMN showed a trend toward lower total complication rates (RR, 0.63; 95% CI, 0.45-0.88; P = .007). In AF ablation, RMN and MCN exhibit comparable efficacy in achieving freedom from AF. However, RMN is associated with a prolonged procedure duration compared to MCN. Nonetheless, RMN offers advantages in terms of reduced fluoroscopy times and lower total complication rates, highlighting its potential for improving procedural safety. The choice between RMN and MCN should be made considering individual patient factors and procedural objectives.