Heart rhythm最新文献

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.

Background: Atrial fibrillation (AF) occurs after heart transplantation (HT) and may increase morbidity and mortality; however, data on its incidence, predictors, and outcomes remain limited.

Objective: To evaluate the incidence of AF and stroke after HT and identify predictors and outcomes of post-HT AF.

Methods: We conducted a retrospective study of adult patients who underwent HT at a high-volume center between January 1, 2005, and September 30, 2024. AF was classified as early (<30 days post-HT) or late (≥30 days). Clinical variables for both recipient and donor were collected. Separate CHA₂DS₂-VASc scores were calculated using recipient and donor age. Predictors of early and late AF were assessed using univariate and multivariable logistic regression.

Results: Among 1,072 patients (median age 55 [IQR 45-63] years; 75% male), AF occurred in 11% (n=111), most commonly as late or combined early and late AF. Donor age, post-HT extracorporeal membrane oxygenation, and pericardial effusion predicted early AF, while rejection, cardiac allograft vasculopathy, and early AF predicted late AF. Stroke occurred in 9% of patients and was independently associated with pre-HT mechanical circulatory support and ischemic time but not AF. CHA₂DS₂-VASc scores incorporating recipient and donor factors predicted post-HT stroke; the donor-derived score also predicted AF. Survival was similar through three years post-HT but was lower in patients with AF at five years (72% vs. 86%, p<0.01).

Conclusions: AF after HT is associated with reduced long-term survival. Both donor and recipient factors contribute, and donor-derived CHA₂DS₂-VASc scoring may aid risk stratification and surveillance.