Heart rhythm最新文献

Background: Elevated remnant cholesterol (RC) is recognized as a risk factor for atherosclerotic cardiovascular disease. However, its association with cardiac conduction block (CCB) remains unclear.

Objective: This study aimed to investigate the relationship between serially measured RC levels and incident CCB.

Methods: This study used data from the Kailuan study. RC level was measured at baseline in 2006 and at biennial follow-up visits. Cumulative average RC levels were calculated using all available RC measurements before incident cases of CCB or the end of follow-up (December 31, 2019). Cox proportional hazards regression and restricted cubic splines were applied to assess the associations.

Results: A total of 80,853 participants (78.12% men; mean age 51.55 ± 12.53 years) were included. During a median follow-up of 10.40 years, 3203 incident CCB cases were identified. A U-shaped association was observed between cumulative average RC levels and the risk of CCB (P nonlinearity = .001). Compared with participants with RC levels of 0.76-1.05 mmol/L, the multivariable-adjusted hazard ratios for CCB were 1.55 (95% confidence interval 1.39-1.72) for RC of <0.76 mmol/L and 1.78 (95% confidence interval 1.61-1.97) for RC of ≥1.40 mmol/L. These findings remained consistent across multiple sensitivity analyses. Similar U-shaped associations were observed for the major subtypes of CCB, including atrioventricular block, left bundle branch block, and right bundle branch block.

Conclusion: Both low and high cumulative average RC levels were associated with an increased risk of CCB and its major subtypes, suggesting the importance of maintaining RC within an optimal range.

Background: Mapping wavefronts within the triangle of Koch is challenging owing to multiple small and large amplitude signals within a short time interval. Ripple mapping was designed to overcome these limitations.

Objective: We tested the feasibility of delineating wavefronts within the triangle of Koch during slow-fast atrioventricular nodal reentrant tachycardia (AVNRT).

Methods: Patients undergoing electrophysiological studies were recruited. Right atrial CARTO maps were collected during atrial pacing, ventricular pacing, and typical AVNRT. Using ripple mapping, we marked His activation during atrial pacing, the earliest retrograde atrial activation during ventricular pacing, the earliest signal during AVNRT (E-AVNRT), and the earliest retrograde right atrial activation during AVNRT.

Results: 72 patients were recruited, with typical AVNRT in 40 patients and a full mapping protocol in 30 patients (6327 ± 948 points collected). The E-AVNRT was 14.7 ± 5.3 mm inferior to the earliest His identified during atrial pacing. A wavefront consistent with slow pathway activation started at E-AVNRT taking 22.2 ± 4.8 ms to reach the His cloud with a line of block demarcating the atrial side. This same line formed the ventricular border of atrial activation during atrial pacing, consistent with slow pathway activation over the right inferior nodal extension. These wavefront signals became sharper approaching His but consistently activated a region inferior to the His cloud, consistent with the right inferior nodal extension activating the lower nodal bundle. Earliest retrograde fast pathway-mediated right atrial activation during AVNRT was 57.3 ± 27.1 ms later and 11.7 ± 6.0 mm from E-AVNRT and distinct from the earliest atrial activation during ventricular pacing (7.0 ± 3.2 mm). Successful ablation sites were closer to E-AVNRT than unsuccessful sites (6.4 ± 3.0 vs 14.8 ± 5.6 mm; 95% confidence interval 5.2-7.6 vs 12.2-17.4 mm; P < .01).

Conclusion: Ripple mapping can delineate slow and fast pathway activation during AVNRT. Lower nodal bundle signals "lead" during AVNRT, inferior to the conventional His cloud. Ripple mapping-guided AVNRT ablation may be feasible.

Paroxysmal supraventricular tachycardia (PSVT) is associated with significant morbidity and affects 1 in 300 people. This article reviews the contemporary management of PSVT and the potential role of intranasal etripamil, a recently Food and Drug Administration-approved intranasal calcium channel blocker that can be used to safely and effectively terminate PSVT in an outpatient setting and avoid urgent medical attention. When combined with the use of wearable devices, this paradigm shift of enabling patients to self-treat PSVT with an on-demand therapy provides another option to be considered in shared decision making for PSVT management.

Background: Hemolysis was recently identified as a side effect of pulsed field ablation (PFA), which raised renal safety concerns. Further systemic effects of PFA-induced hemolysis remain unknown.

Objective: This study aimed to investigate the thromboinflammatory potential of PFA and the systemic biological effects of PFA-induced hemolysis.

Methods: We prospectively included 60 patients with paroxysmal atrial fibrillation receiving pulmonary vein isolation using a pentaspline PFA system (n = 30) or radiofrequency ablation (RFA) (n = 30). Biomarkers of inflammation, platelet activation, endothelial cell damage, hemolysis, and renal function were analyzed at 3 timepoints. Pericarditis, early recurrences, and 6-month rhythm outcomes were further assessed.

Results: Intravascular hemolysis was detected in 100% of PFA-treated patients after a mean of 42.8 ± 3.7 deliveries. Leukocyte release (Δ3.0 ± 2.3 vs 3.6 ± 2.3 × 10⁹/L; P = .254), acute platelet activation, and endothelial cell damage biomarker changes were similar between PFA and RFA. Nitric oxide levels decreased significantly in the PFA group only (-26.5% ± 17.8%; P < .001). Although no acute kidney injury occurred, hemolysis burden was significantly associated with creatinine increase, inflammation, and platelet activation. Female sex was the only independent predictor of significant hemolysis after PFA (odds ratio, 7.8; 95% confidence interval, 1.2-50.2; P = .031). In-hospital pericarditis was lower with PFA (10.0% vs 33.3%; P = .028), whereas early (20.0% vs 26.7%) and late recurrences (6.7% vs 10.0%; all P > .05) were similar between groups.

Conclusion: PFA is associated with a similar thromboinflammatory reaction as RFA. PFA-induced hemolysis occurs in all patients and is significantly associated with renal function decline, inflammation, and platelet activation even with limited PFA deliveries. Females are at a higher risk of significant hemolysis after PFA.

Background: Accurate identification of the earliest activation site is essential for successful catheter ablation of premature ventricular complexes (PVCs).

Objective: This study aimed to compare first deflection (FD) and near-field (NF) detection using the Turbomap modality on the Ensite X system.

Methods: A retrospective analysis was conducted on 59 patients (71 ablation sites) who underwent first-time PVC ablation. All cases were remapped using Turbomap to extract FD and NF parameters at the earliest activation sites. Comparisons were based on differences in local activation time (ΔLAT), peak frequency (Δ peak frequency), activation area (Δ activation area), and spatial distance.

Results: FD detection identified significantly earlier LAT (-37.8 ± 14.7 msec vs -27.9 ± 12.4 msec, P < .001). Conversely, NF detection detected a higher peak frequency (249.7 ± 102.8 Hz vs 219.3 ± 103.9 Hz, P = .044). No significant differences were observed in the area of the earliest activation within 5 msec between techniques. When cases were categorized by PVC origin (right ventricular outflow tract vs left ventricular summit) and by ablation strategy (single-chamber vs multi-chamber ablation), no significant differences in mapping parameters were found. However, a shorter distance between the FD- and NF-annotated earliest activation sites was significantly associated with successful PVC elimination within 2 ablation attempts (3.1 ± 2.7 mm vs 8.3 ± 5.0 mm, P < .001).

Conclusion: FD detection provides earlier LAT activation, while NF detection captures higher-frequency signals. Closer spatial correlation between FD and NF may predict more efficient ablation, even though mapping parameters did not differ significantly across categorized groups.

Background: Cardiac resynchronization therapy (CRT) can improve clinical outcomes in patients with dyssynchronous heart failure, but many patients selected according to the current guidelines do not respond.

Objective: This study aimed to externally validate an explainable deep learning algorithm (the FactorECG algorithm) for predicting response after biventricular pacing.

Methods: We previously trained a deep learning algorithm on >1 million electrocardiogram (ECG) median beats to learn the underlying generative factors of the ECG and applied it to 1306 patients with CRT from the Netherlands. Using the extracted 21 explainable factors, a model predicting the risk of volumetric nonresponse and poor clinical outcomes was developed. In the present analysis, this model was externally validated in a cohort of 161 patients with CRT from the University of Virginia for volumetric nonresponse only. Subsequently, the added value of clinical and cardiac magnetic resonance imaging-derived predictors was investigated.

Results: The original model significantly outperformed American Heart Association criteria for left bundle branch block for the prediction of nonresponse {C-statistic 0.67 (95% confidence interval [CI] 0.59-0.76) vs 0.51 (95% CI 0.41-0.60), respectively}. A refitted FactorECG-based model performed similarly to a model also integrating indices of mechanical dyssynchrony (C-statistic 0.74 [95% CI 0.66-0.82] vs 0.70 [95% CI 0.62-0.77], respectively). A combination of both models improved response prediction (C-statistic 0.79 [95% CI 0.71-0.85]).

Conclusion: In this external validation study, an explainable ECG-only algorithm for the prediction of nonresponse after CRT device implantation generalized well to a lower-risk population from a different hospital. Adding indices of mechanical dyssynchrony and right ventricular function might be of additional value when evaluating volumetric response.

Background: Arrhythmia-risk assessment in congenital long-QT syndrome (LQTS) and drug-induced QT prolongation (diQTP) is primarily based on clinical, genetic, and electrical parameters. Electromechanical window (EMW) (aortic-valve closure time minus QT interval) assessment outperformed heart rate-corrected QT interval (QTc) as a predictor of symptomatic status in LQTS.

Objective: The study aimed to investigate the relationship between temporal QTc and EMW dynamics, and ventricular tachyarrhythmia (VT) timing in LQTS and diQTP.

Methods: 47 patients with LQTS/-VT, 18 patients with LQTS/+VT, 9 patients with diQTP/+VT, and 26 controls were included. QTc and EMW were obtained from standard 12-lead electrocardiograms and electrocardiogram-echocardiograms at 2 or 3 time points. Patients with +VT were included if EMW/QTc assessments were performed within 2 weeks before or after VT.

Results: In control subjects, EMW remained stably positive over time. In patients with LQTS/-VT, EMW was negative without significant variation. In patients with LQTS/+VT and diQTP/+VT, transient accentuations of EMW negativity were observed at the time point closest to VT (2 days [1-7] to arrhythmia), regardless of whether measured before or after VT. Temporary EMW negativity accentuation was driven by foreshortening of the mechanical systole despite concurrent QT prolongation. EMW recovery after VT was similar for patients with or without beta-blocker therapy. Multiple logistic regression analysis identified EMW negativity and EMW dynamics (ΔEMW) as independent predictors of imminent VT in LQTS. An EMW of -75 ms and a ΔEMW of -39 ms were optimal cutoffs to predict emergent arrhythmic deterioration in the LQTS cohort.

Conclusion: Temporary accentuation of EMW negativity is a marker of impending VT in patients with LQTS and diQTP.

Background: The efficacy and safety of monopolar biphasic focal pulsed field ablation (F-PFA) in close proximity to the atrioventricular (AV) node remain unknown.

Objective: This study aimed to describe the effect of direct or indirect F-PFA application at the AV junction.

Methods: In pigs, F-PFA (Centauri, CardioFocus) was applied directly at the AV junction (n = 3) and indirectly from within the aortic noncoronary cusp (NCC) (n = 5), followed by macroscopic gross and histologic analysis. In 5 patients planned for a pace-and-ablate strategy, F-PFA was applied at the AV junction. In 1 patient with recurrent para-Hisian atrial tachycardia and previously failed ablation, F-PFA was applied from within the NCC.

Results: In pigs, direct F-PFA applications at the AV junction were associated with junctional beats and resulted in complete AV block after 2-3 F-PFA applications. Tissue histology revealed a lesion depth of approximately 8 mm with minor hemorrhage and leukocyte infiltration. F-PFA from within the NCC resulted in a transient increase in the AV node's Wenckebach cycle length and 1 pig had transient AV block, which recovered within 10 minutes. In 5 patients undergoing pace-and-ablate strategy, F-PFA applications at the AV junction resulted in sustained AV block. In 1 patient, application of F-PFA from within the NCC resulted in termination and noninducibility of a recurrent incessant para-Hisian atrial tachycardia without AV block. There were no immediate or long-term complications.

Conclusion: F-PFA directly at the AV junction results in nonreversible AV block. F-PFA from within the NCC may represent a promising strategy for treating para-Hisian arrhythmias while preserving AV conduction.