Heart rhythm最新文献

Background: Pulsed field ablation (PFA) has emerged as a promising alternative to thermal catheter ablation for pulmonary vein isolation in atrial fibrillation (AF).

Objectives: To estimate the efficacy and safety of PFA versus thermal ablation in AF.

Methods: We searched PubMed, Embase, and Cochrane through July 2025 for studies comparing PFA with thermal ablation. Individual patient data were reconstructed from Kaplan-Meier curves, and hazard ratios (HR) were estimated using a Cox frailty regression model. Time-to-benefit was assessed to determine when the treatment effect becomes clinically meaningful. Study-level odds ratios (OR) and mean differences with 95% credible intervals (CrI) were estimated with a Bayesian random-effects model and non-informative priors for primary analyses.

Results: Twelve studies (4 RCTs, 8 observational) involving 3,120 patients (46.6% PFA) were included. Time-to-event analysis (1 RCT, 6 observational) showed PFA was associated with higher freedom from arrhythmia recurrence (HR 0.68; 95% CrI, 0.55-0.84). A time to benefit of 12 months was needed to prevent 5 atrial arrhythmia recurrences per 100 PFA-treated patients. In study-level analyses, the probability of a clinically meaningful reduction (OR < 0.8) in arrhythmia recurrence was 34.1% for RCTs and 96.5% for observational studies. PFA had a high likelihood of shorter procedural and left atrial dwell times. Safety outcomes showed no consistent excess risk with PFA.

Conclusion: In patients with AF undergoing catheter ablation, PFA was associated with reduced arrhythmia recurrence compared with thermal ablation, with larger effects in observational studies and more modest effects in RCTs, and no signal of increased harm.

Background: Heart failure is a global health challenge with a significant impact on patients and healthcare systems. Identifying those at risk of cardiac death remains difficult but essential. Elevated sympathetic nerve activity (SNA) is linked to ventricular arrhythmias, highlighting its value in diagnosis and risk stratification.

Objective: Investigate the use of skin SNA (SKNA) as a marker for stratifying patients at risk of cardiac death beyond established clinical predictors and heart rate variability (HRV).

Methods: We analyzed 20-min, 1-kHz orthogonal ECG recordings from 588 HF patients in the MUSIC dataset after excluding device carriers. SKNA was extracted using high-pass filtering (>300 Hz). We quantified traditional amplitude-based SKNA metrics derived from moving average (MA) and root mean square (RMS) signals, and raw-signal (rSKNA) distribution and nonlinear complexity features, including largest Lyapunov exponent (LE) and multiscale entropy (MSE). Associations with outcomes were assessed using univariate analyses and multivariable Cox models adjusted for age, BMI, LVEF, NYHA class, diabetes, and prior myocardial infarction. HRV indices (SDNN, LF/HF) were evaluated for comparison.

Results: MA/RMS-based SKNA metrics did not show consistent between-group differences. In contrast, rSKNA complexity measures (LE and MSE) were lower in patients who experienced cardiac death (sudden and non-sudden). In adjusted Cox models, LE and MSE remained independently associated with cardiac death (HR ≈ 0.75-0.80, p<0.05), whereas SDNN and LF/HF were not independently associated.

Conclusion: rSKNA complexity measures, particularly MSE, provide complementary, non-invasive prognostic information for sudden and non-sudden cardiac death in HF beyond established clinical predictors and HRV.

Background: Cardiac implantable electronic devices (CIEDs) rely on metal-oxide-semiconductor gating transistors to control pacing pulse delivery. Gate-oxide (GO) defects can produce high leakage currents that compromise battery longevity, electronic circuit function, and lead-electrode integrity.

Objective: To assess manufacturers' reports of CIED gate-oxide failures, characterizing their presentation, timing, clinical impact, and findings from engineering analyses of explanted devices.

Methods: We searched the FDA's publicly available Manufacturers and User Facility Device Experience (MAUDE) database for reports containing the terms "gate oxide" or "oxide" submitted by Abbott, Biotronik, Boston Scientific, and Medtronic.

Results: We identified 178 GO failures reported for Boston Scientific devices (2011-2025) and 30 for Medtronic devices (2009-2021); none were reported for Abbott or Biotronik. Median time to failure was 5.8 months (interquartile range [IQR] 2.9-11.6). Pacemakers failed earlier (median 4.7 months; IQR 2.8-8.5) than implantable cardioverter-defibrillators (10.0 months; IQR 5.6-18.8). Presenting findings included premature battery depletion (n=83), Safety Mode activation (n=45), low lead impedance (n=57), loss of telemetry (n=25), and high power consumption (n=21). Engineering analyses identified lead-electrode corrosion in 10 explanted leads, with electrical discontinuity in 4. Major adverse events included death (n=2), cardiac arrest/asystole/shock (n=5), syncope (n=7), and heart failure (n=6).

Conclusion: Gate-oxide defects represent an early, manufacturing-related semiconductor failure mechanism in CIEDs that can rapidly deplete batteries, disable life-saving therapy, and contribute to lead-electrode corrosion. Early recognition of characteristic device and clinical patterns may facilitate risk mitigation, particularly in vulnerable patients.

Background: Although asymptomatic atrial fibrillation (AF) is common, screening has not consistently improved outcomes, possibly due to challenges identifying those most at risk for asymptomatic AF.

Objective: To identify risk factors associated with increased likelihood of presenting with asymptomatic versus symptomatic AF and to evaluate and compare subsequent cardiovascular and mortality outcomes across these patient groups.

Methods: In the VITAL Rhythm Study (n=25,114, free of baseline CVD and AF), time-updated multivariable Cox competing-risk models identified risk factors differentially associated with new-onset asymptomatic versus symptomatic AF. Additional models with time-dependent indicators for AF type and interim CVD events assessed relative risks of subsequent CVD and mortality associated with asymptomatic and symptomatic AF.

Results: Over a median of 7.3 years, 5.0% developed new-onset AF, of these 29.3% were asymptomatic. Male sex, BMI, and elevated SBP were more strongly associated with asymptomatic versus symptomatic AF (P differential < 0.04 for all). Both groups had similarly increased risks of stroke, myocardial infarction, and death following AF onset. However, the risk of HF was higher for symptomatic AF (P differential=0.03). After adjusting for interim non-fatal CVD, mortality risk was completely attenuated in patients with asymptomatic AF (HR 0.98; 0.67-1.45), but not in symptomatic AF (HR 1.54; 1.19-1.98; P differential =0.046).

Conclusion: Men and individuals with higher BMI and SBP are more likely to have asymptomatic AF. Mortality risk in these patients is largely driven by potentially preventable CVD events, emphasizing the importance of targeted screening and early cardiovascular risk management to improve outcomes.

Background: Lumenless and stylet-driven leads used for left bundle branch area pacing differ in design and have a significant implantation learning curve. While prior studies examined longer helices for deep septal pacing, the influence of other design variables remains unclear.

Objective: Evaluate how helix design and axial force affect interventricular septum insertion efficacy.

Methods: Rigid leads were developed using helical coils with variable outer diameter, number of turns and pitch. Porcine septa (n=16) were clamped perpendicularly for insertion using an optimized rotation-response system. Leads were tested under low (30g) and high (60g) axial force conditions to represent lumenless and stylet-driven leads, respectively, and a fixed number of rotations were delivered at a constant rate. Each helix design (n=8) was tested 3x per axial force at three septal sites. Insertion depth, muscle-torque and visual feedback were recorded. Insertion was successful if depth exceeded coil length without surface entanglement. Effects of design factors were compared.

Results: At 30g, more helix turns significantly improved insertion success (P=0.04), while fewer turns frequently produced entangled failure (P=0.04) marked by high torque variability (P<0.001). Smaller-pitch helices trended toward higher torque and success, whereas larger pitch achieved greater depth (P=0.05). Larger outer diameters also trended toward higher torque and improved success at 30g. At 60g the influence of helix design variable diminished and consistently yielded higher than at 30g.

Conclusion: An optimized lead rotation-to-translation system elucidates how helix geometry and axial force interact during septal insertion. These interactions are explainable using an intuitive mechanical framework which is helpful for optimizing lead design.

Background: Trans-right atrial appendage (RAA) pericardial carbon dioxide (CO₂) insufflation has been shown feasible and safe in small case series. The optimal RAA perforation site remains undefined.

Objective: To identify the RAA region offering the most favorable spatial relationships for safe trans-RAA pericardial access using contrast-enhanced cardiac computed tomography (CT).

Methods: Fifty consecutive patients (28 men; 57 ± 12 years) undergoing contrast-enhanced cardiac CT were studied. The RAA was analyzed in three equidistant axial planes (basal, mid, high) oriented perpendicular to a vertical line through the RAA apex. Each plane was divided into 6 segments - septal and lateral, each subdivided into posterior, mid, and anterior regions. Distances to adjacent epicardial structures were measured for each segment.

Results: Lateral RAA segments directly contacted the parietal pericardium (0 mm [IQR 0-0 mm]). Posterior and mid-septal segments closely approximated the aorta (3.8 mm [2.3-8.2 mm]). Only the septal anterior region bordered a visible pericardial space between the parietal pericardium, aorta, RCA, and RVOT. The greatest separations occurred at the high septal anterior plane (RVOT 12.4 mm, aorta 6.3 mm, parietal pericardium 9.8 mm, RCA 13.4 mm). In 4 patients, RCA branches coursed within 5 mm of the RAA. Results were consistent in an additional validation cohort of 8 patients undergoing trans-RAA CO₂ insufflation and 2 patients with aortic dilatation.

Conclusions: The high septal anterior RAA offers the most favorable anatomical clearance for trans-atrial pericardial access, whereas the lateral and remaining septal walls lie in close proximity to the parietal pericardium and aorta.

Background: Population-based data on Long QT syndrome (LQTS) is lacking. New Zealand has a national LQTS registry, molecular autopsy program and standardised investigation of resuscitated cardiac arrest (RSCA).

Objective: To describe trends in LQTS detection and presentation with RSCA/sudden cardiac death (SCD) over 24 years.

Methods: Review of data on registry participants who underwent genetic testing for LQTS presenting between 2000 and 2023.

Results: Among 915 diagnosed with LQTS, 378 probands, (mean QTc 512 +/- 52 ms presented with SCD (26/378, 7%), RSCA (82, 21%), syncope or seizure (122, 32%), incidental/other (148, 40%). Causative genetic variants were found in 165/378 probands (44%): 98 KCNQ1 (59 %), 41 KCNH2 (25%), 7 SCN5A (4%), and 19 other genes (12%). 593/915 participants (65%) were on therapy (beta blocker (565, 62%), implantable cardioverter defibrillator (134, 16%) and/or left sympathetic cardiac denervation (69, 8%)). Three likely arrhythmic deaths (0.3%), and 23 appropriate ICD shocks (3%) occurred during follow up (median 12 years). Detections of LQTS/population was 0.5/100,000 in 2000, 1.6/100,000 in 2009 and 0.4/100,000 in 2023. Presentation with RSCA decreased by 10%/year from 2007. Presentation with death decreased by 22%/year from 2014 (p=0.026), with no deaths from 2019 to 2023.

Conclusions: Decreasing rates of detection of LQTS in recent years suggests that most cases have been discovered in New Zealand. Decreasing cardiac arrest and sudden death due to LQTS is likely related to the success of the overall program.

Background: Women with atrial fibrillation (AF) often experience worse outcomes after catheter ablation, but prior evidence is confounded by heterogeneity in AF types and ablation strategies.

Objective: To determine whether sex remains an independent determinant of recurrence in patients with persistent atrial fibrillation (PeAF) undergoing standardized ablation.

Methods: We retrospectively analyzed 2,864 patients undergoing first-time "2C3L" ablation (pulmonary vein isolation plus left atrial roof, mitral isthmus, and cavotricuspid isthmus lines) for PeAF between December 2020 and August 2023. The primary endpoint was atrial arrhythmia recurrence beyond the 3-month blanking period. We performed Kaplan-Meier analyses, restricted mean survival time (RMST; truncation at 1,095 days), multivariable Cox regression, inverse probability of treatment weighting (IPTW), prespecified subgroup analyses, and 1:1 propensity score matching (PSM).

Results: Women comprised 826 (28.8%) patients. During a median follow-up of 357 days, recurrence was higher in women than in men (40.0% vs 34.4%; log-rank P = 0.002). RMST was 698.2 days in women and 759.4 days in men (difference -61.2 days; 95% CI -100.0 to -22.4; P = 0.002). Female sex was independently associated with recurrence in the fully adjusted Cox model (hazard ratio [HR] 1.24; 95% CI 1.07-1.43; P = 0.003) and in the IPTW analysis (HR 1.32; 95% CI 1.12-1.54; P = 0.001). Findings were consistent after 1:1 PSM (826 pairs; HR 1.32; 95% CI 1.12-1.54; P = 0.001) CONCLUSIONS: In this large PeAF cohort treated with 2C3L strategy, female sex was independently associated with earlier and more frequent post-ablation atrial arrhythmia recurrence.

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. Substantial wait-times exist for catheter ablation treatment in some jurisdictions. The economic consequences of wait-times have not been characterized.

Objective: To determine drivers of healthcare expenses by phase of cost and assess contribution of wait-times among patients receiving AF ablation.

Methods: This observational cohort study included patients who received AF ablation in Ontario, Canada between April 2016 and March 2023. Per-patient cumulative healthcare costs were the primary outcome, presented by phase of cost from AF diagnosis to 1 year following ablation. Hierarchical generalized linear models with a logarithmic link and gamma distribution assessed drivers of cost by phase. The primary exposure was wait-times defined as diagnosis-to-ablation, diagnosis-to-referral, and referral-to-ablation times.

Results: Our cohort included 8,403 recipients of de novo AF ablation with a median diagnosis-to-ablation time of 29 (IQR: 16-50) months. The median (IQR) pre-ablation cost was $15,353 ($8,424-$27,776) while the median 1-year cost post-ablation was $19,929 ($16,595-$25,702). Diagnosis-to-ablation time was significantly associated with increased pre-ablation costs (Rate ratio [RR] 1.02 per month, 95% CI 1.02-1.02). Wait-times were positively associated with post-ablation costs (RR 1.001 per month increase of diagnosis-to-ablation time, 95% CI 1.000-1.001), albeit with a smaller magnitude. Medical comorbidity, including heart failure was significantly associated with increased pre-ablation (RR 1.28, 95% CI 1.24-1.33) and post-ablation costs.

Conclusion: Patients receiving AF ablation experience distinct phases of cost accumulation and wait-times for ablation have a limited contribution to cumulative costs.