Journal of Cardiovascular Electrophysiology最新文献

Background: Insertable cardiac monitors (ICMs) provide long-term continuous monitoring for arrhythmia diagnosis and management for various clinical indications. However, little data exists on comprehensive real-world arrhythmia diagnostic yield and therapy rates in patients indicated for ICMs with validated artificial intelligence (AI) algorithms enabling large-scale, automated adjudication of ICM-detected episodes. We report the largest real-world analysis of arrhythmia detection as well as medical and procedural therapies in patients with ICMs implanted for guideline-approved indications with long-term monitoring.

Methods: Patients who received a Reveal LINQ ICM between October 1, 2016, and June 30, 2020, with ≥ 1 year of follow-up were identified in two databases (Medtronic CareLink data warehouse, N = 12 020, and Optum Clinformatics Data Mart claims database, N = 17 037) to analyze arrhythmia detections and therapeutic interventions, respectively. Patients were categorized by clinical indication for ICM placement. All device-detected ECGs were identified and processed through arrhythmia-specific AI algorithms. Therapeutic interventions included procedural interventions (cardiovascular implantable electronic device implantation, cardioversions, and ablations) and medication initiation or titration (antiarrhythmics, rate-control medications, and oral anticoagulants) after ICM implant.

Results: Mean (SD) follow-up in the CareLink and Clinformatics claims databases was 24.6 (12.7) and 40.8 (15.6) months, respectively. Of the 12 020 patients in the arrhythmia detection analysis, 7284 (60.6%) had ≥ 1 arrhythmia detected (56.3% in the suspected AF population; 80.1% in the AF management population), and 376 (28.9%) had ≥ 2 arrhythmias detected during long-term follow-up. Among syncope patients with arrhythmia(s) detected, 71.2% had a finding other than pause/bradycardia; 50.4% of cryptogenic stroke patients and 62.6% of AF management patients with arrhythmias had ≥ 1 finding other than AF. Of the 17 037 patients in the therapeutic interventions analysis, 9820 (57.6%) had a therapeutic action post-ICM insertion, with 25% of all patients receiving a procedural intervention, and > 50% undergoing a medication adjustment. Mean (SD) follow-up to first arrhythmia detection was 7 (9) months. Mean (SD) duration from ICM insertion to therapeutic action was 13 (13) months for procedures and 7 (11) months for medication initiation.

Conclusions: Long-term continuous monitoring with ICMs enables identification of multiple arrhythmias that may have otherwise remained undetected and rules out arrhythmias in ~40% regardless of indication. Medication adjustments and/or procedural interventions related to the management of arrhythmias were observed in over half of ICM recipients during long-term follow-up.

Background: Left bundle branch block (LBBB) is associated with heterogeneous electrical and structural remodeling; however, the interplay between myocardial fibrosis and conduction abnormalities remains incompletely characterized.

Aims: To investigate fibrosis distribution and electrical activation patterns in LBBB patients with preserved (LBBB idiopathic [LBBBi]) and reduced (15 cardiac resynchronization therapy [CRT] recipients) systolic function using noninvasive electrocardiographic activation mapping (NEAM) and late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR).

Materials and methods: Twenty LBBB patients (15 CRT, 5 LBBBi) and five healthy volunteers (HV) underwent NEAM and LGE-CMR. Global and segmental activation times (epicardial/endocardial ATs), fibrosis volume, and latest activation zone (LAZ) localization were analyzed. Segmental correlations between fibrosis and activation parameters were evaluated in the CRT group.

Results: CRT patients demonstrated longer total ATs than LBBBi (176 ± 18 vs. 148 ± 10 ms, p < 0.001). LAZ localized to segments 5-6 in 80% of cases, with displacement in three CRT patients with midwall fibrosis. Fibrosis (17.4 [7.3-53.7] cm³) was present in 86.7% of CRT patients but absent in LBBBi and HV. Global ATs showed no correlation with fibrosis volume (r = -0.159, p = 0.571), but segmental fibrosis volume moderately correlated with epicardial (r = 0.37, p < 0.001) and endocardial (r = 0.307, p < 0.001) ATs. Most segments in both groups demonstrated prolonged epicardial conduction, while endocardial conduction remained near-normal.

Conclusion: Integrated NEAM-LGE-CMR analysis demonstrated that myocardial fibrosis modulates local conduction abnormalities without influencing global activation times. All LBBB patients exhibit prolonged epicardial activation time regardless of fibrosis burden, while endocardial activation time remains preserved in most left ventricular segments.

Background: Patients with end-stage renal disease (ESRD) on hemodialysis are at increased risk for bacteremia, which may necessitate transvenous lead extraction (TLE) if a cardiac implantable electronic device (CIED) is present. Most data on outcomes of TLE in ESRD come from small, single-center studies.

Methods: The National Inpatient Sample database was analyzed to identify hospitalizations where patients underwent TLE between 2016 and 2021. Baseline demographics, comorbidities, and outcomes were stratified by history of ESRD.

Results: We identified 98 115 weighted hospitalizations where patients underwent TLE, of which 5005 (5%) had a history of ESRD. Patients with ESRD were younger and had a higher prevalence of comorbidities including congestive heart failure, diabetes, hypertension, and liver dysfunction. Compared to those without ESRD, in-hospital mortality was significantly higher in patients with ESRD undergoing TLE (10.4% vs. 2.5%, p < 0.001). The incidence of vascular complications (including superior vena cava perforation) and cardiogenic shock was also higher in patients with ESRD, as was the length of stay and total hospitalization cost. Even after adjustment for baseline differences, in-hospital mortality after TLE remained significantly higher in patients with ESRD (adjusted odds ratio [ORs] 2.1, 95% confidence interval 1.6-2.7).

Conclusion: In a nationally representative cohort, unadjusted in-hospital mortality among patients with ESRD undergoing TLE is over 10%, and even after adjustment for covariates, patients with ESRD were more than twice as likely to die in the hospital compared to non-ESRD patients undergoing TLE. The increased availability of CIEDs without transvenous hardware may mitigate some of the long-term burden of device implantation in patients with ESRD.

Background: Pre-implantation screening is a crucial step in preventing inappropriate sensing in patients with subcutaneous implantable cardioverter defibrillators (S-ICDs). Paced QRS-T morphology may influence screening outcomes. We aimed to explore the impact of pacing rhythm and different pacing sites on pre-implantation screening of S-ICD.

Methods and results: This prospective, single-center study enrolled patients referred for radiofrequency ablation, with both left and right-heart access. A contact-force ablation catheter was used to mimic ventricular pacing at different sites. Automatic screening tests for S-ICD eligibility were performed during pacing and sinus rhythm. The impact of pacing sites on S-ICD eligibility was assessed. Thirty patients (age 54.0 ± 15.0 years, 73.3% male) were enrolled. The overall passing rate during intrinsic sinus rhythm was 86.7%. Compared with sinus rhythm, conduction system pacing from His bundle or left bundle branch demonstrated comparable pass rates and the number of passed vectors, whereas right ventricular septum (RVS) pacing exhibited significantly lower pass rates and less pass vectors. Among all RVS pacing sites, the lowest pass rate was observed at the apical portion, followed by middle and basal portion (p < 0.001 for all comparisons).

Conclusion: Conduction system pacing preserves patient eligibility for S-ICD comparable to sinus rhythm, while RVS pacing significantly impairs sensing performance, with the greatest deterioration observed in apical pacing. These findings underscore the advantages of conduction system pacing in optimizing sensing function for patients eligible for both S-ICDs and pacemakers.

Accessory pathways (APs) are classified as typical or variant according to their atrial and ventricular insertions. Typical APs connect atrial and ventricular working myocardium directly across the annulus, whereas variant APs-including the atrio-Hisian pathway (AHP), fasciculoventricular pathway (FVP), nodofascicular pathway (NFP), and nodoventricular pathway (NVP) pathways-partially or fully engage the atrioventricular node-His (AVN-His) axis. Focusing on trans-annular APs in the right para-septal region, this review emphasizes how their anatomic course and spatial relationship to the AVN-His axis determine their electrocardiographic (ECG) and electrophysiologic (EP) manifestations. Accurate interpretation of these features requires detailed understanding of para-septal anatomy. By integrating anatomic, ECG, and EP correlations, a unified schematic model is proposed to describe the relative positions, insertion sites, and conduction relationships of typical and variant APs within the right para-septal region. This framework clarifies how subtle anatomic variations along the AVN-His axis account for the distinct yet overlapping ECG and EP features of these pathways.

Background: A dual-chamber leadless pacemaker (LP) system has been developed, employing distinct atrial leadless pacemaker (ALP) and ventricular leadless pacemaker (VLP) devices that maintain atrioventricular synchrony via wireless implant-to-implant (i2i) communication with each beat. A new i2i communication-free programming option was introduced to extend battery longevity and minimize unnecessary ventricular pacing by providing rate-modulated atrial pacing with backup ventricular pacing when needed (AAI(R) + VVI). The clinical safety and longevity improvement have not been evaluated commercially.

Methods: Patients indicated for dual-chamber pacing with new or existing dual-chamber LP implants were enrolled in this prospective, nonblinded, interventional study. Device diagnostics and battery longevity were interrogated before and after 6 months (6 M) of AAI(R) + VVI programming, with any programming-related complications or symptoms noted. Total ALP and VLP longevities were compared for DDD(R) at enrollment versus AAI(R) + VVI at 6 M.

Results: Dual-chamber LP systems in 139 patients at six centers were evaluated (76 ± 11 years; 53% male; PR 210 ± 56 ms; 80% sinus node dysfunction, 16% AV block of any degree), including 16% new and 84% existing implants (enrolled 7.9 ± 7.5 months postimplant). The 84 patients completing the study (n = 55 did not return) demonstrated a complication-free rate of 100.0% and a symptom-free rate of 97.6% (n = 2; fatigue, dizziness, shortness of breath). In the 32 patients enrolled with existing implants already in DDD(R) mode who also completed the 6 M visit, AAI(R) + VVI extended the longevities of ALPs by 93% (5.8 ± 1.1 to 11.1 ± 2.7 years, p < 0.001) and VLPs by 61% (10.9 ± 2.1 to 16.9 ± 1.2 years, p < 0.001).

Conclusion: Clinical use of AAI(R) + VVI programming in dual-chamber LPs over 6 M resulted in no complications, minimal symptoms, and significantly extended ALP and VLP battery longevities.

Background: Compared to permanent surgically created hemodialysis (HD) vascular access, tunneled vascular access catheters for HD may pose an even higher risk of blood stream infection (BSI). For patients with transvenous cardiac implantable electronic devices (CIEDs), the risk of device infection associated with tunneled HD catheter is not well-characterized.

Methods: The Nationwide Readmissions Database (NRD) 2016-2021 was used for analysis. Patients with end-stage kidney disease (ESKD) and a CIED who were admitted for any reason were identified by ICD-10 codes and stratified based on whether a new tunneled HD catheter was placed during the index admission. Readmissions with CIED infection within 180 days were compared between the two groups (new tunneled HD catheter during index admission vs. ESKD without need for new dialysis access).

Results: We identified 117 573 index admissions in patients with ESKD and a CIED, out of whom 8677 (7.4%) underwent placement of a new, tunneled HD catheter during the index admission. Readmission within 180 days occurred in 531 patients (6.1%) among those who required a new, HD catheter during index admission, compared to 3572 (3.3%) among those who did not. In multivariable models, a new, HD catheter during index admission was associated with a significantly increased risk of readmission with CIED infection within 180 days (adjusted odds ratio [aOR]: 1.92, 95% confidence interval [CI]: 1.66-2.22, p < 0.001). During the readmission, patients with a new tunneled catheter were more likely to present with blood stream infection (57.8 vs. 45.8%, p < 0.001), infectious endocarditis (13.4 vs. 10.1%, p < 0.001), and to experience in-hospital major adverse cardiovascular events (MACE) (10.5 vs. 9.9%, p = 0.006).

Conclusion: Among patients with CIEDs, placement of a new tunneled vascular access catheter for HD was associated with a roughly twofold increased risk of readmission with CIED infection within 180 days, compared to patients with ESKD who did not require new vascular access. Readmissions with CIED infection were associated with significantly worse outcomes, including higher in-hospital MACE. To the extent possible, temporary tunneled HD catheters should be avoided in ESKD patients with CIEDs.