T-Wave oversensing (TWOS) is a type of pacemaker malfunction that can result in inappropriate tachyarrhythmia detection and loss of pacing, attenuating potential benefits of cardiac resynchronization therapy (CRT). We present a case series of TWOS after left bundle branch pacing (LBBP) in the First Affiliated Hospital of Nanjing Medical University from 2020 to 2024. By analyzing underlying mechanisms and summarizing feasible solutions, we highlight the particularity and complexity of TWOS. It can occur immediately after procedure or be detected after a relatively long period of time. The harm of TWOS should be dealt with in a timely manner.

Background Conduction system pacing (CSP), including His bundle pacing (HBP) and left bundle branch area pacing (LBBAP), offers a physiological alternative to conventional pacing. However, current evidence is limited by small sample sizes, short follow-up, and inconsistent LBBAP definitions. Objective This study evaluated the long-term outcomes, safety, and lead performance of CSP in a large multicenter cohort, and provided a precise LBBAP classification for investigating its impact on clinical outcomes. Methods This prospective registry-based study included patients receiving CSP at 5 Chinese centers from 2019 to 2021. LBBAP was classified as left bundle branch pacing (LBBP), left ventricular septal pacing (LVSP), or unclassified LBBAP based on the presence, absence, or uncertainty of left bundle branch capture. Pacing and clinical outcomes were analyzed. Results Of 3,336 enrolled patients, 3,167 successfully received CSP (557 HBP, 2,610 LBBAP), with a mean follow-up of 41.3 ± 14.0 months. LBBAP comprised LBBP (84.2%), unclassified (12.5%), and LVSP (3.3%). In patients with LBBB and heart failure with reduced ejection fraction, LBBP and HBP achieved the greatest LVEF improvements (+20.7% and +21.9%), while LVSP showed the least (+12.1%). LVSP was associated with higher mortality or heart failure hospitalization (33.3%) compared with LBBP (8.6%) and unclassified LBBAP (15.4%). Threshold increases ≥1 V/0.5 ms occurred in 5.03% HBP vs 1.80% LBBAP (P < 0.001). Procedural complications (excluding threshold rise) occurred in 1.3% of both groups. Conclusions CSP demonstrated long-term safety and stability. Subclassification of LBBAP enhances clinical precision, with LBBP capture yielding a higher positive clinical outcomes and LVSP with inferior outcomes, especially in cardiac resynchronization therapy patients.

Obesity-related cardiomyopathy (OCM) is characterized by pathological cardiac remodeling and progressive functional decline, often accompanied by mitochondrial dysfunction, particularly aberrant mitophagy. The role of the core circadian gene brain and muscle ARNT-like protein 1 ( Bmal1) in OCM remains unclear. In this study, we employed a high-fat diet (HFD)-induced OCM mouse model, a cardiomyocyte-specific Bmal1 knockout ( Bmal1 CMKO) model, and a palmitic acid (PA)-induced H9c2 cardiomyocyte injury model to investigate the function of Bmal1. In vivo, BMAL1 expression was reduced in hearts of HFD mice; HFD- Bmal1 CMKO mice exhibited exacerbated myocardial hypertrophy, fibrosis, functional impairment, and apoptosis, accompanied by increased expression of the mitophagy-related proteins PINK1, Parkin, and LC3-II. In vitro, PA exposure decreased BMAL1 expression, disrupted mitochondrial membrane potential, increased reactive oxygen species generation, and induced excessive mitophagy; these effects were aggravated by Bmal1 silencing and attenuated by Bmal1 overexpression, which also improved cell viability. Collectively, these findings indicate that Bmal1 plays a protective role in OCM, and its downregulation may be a key contributor to obesity-induced cardiac remodeling and dysfunction. Mechanistically, BMAL1 downregulation was accompanied by activation of the PINK1/Parkin signaling and enhanced mitophagy under lipid stress. By restraining excessive mitophagy and preserving mitochondrial function and metabolic homeostasis, Bmal1 and its associated pathways may represent promising therapeutic targets for OCM.

We report a 14-year-old female with a history of surgically corrected Ebstein anomaly, including a bidirectional Glenn shunt and atrial septostomy. Following a bioprosthetic tricuspid valve replacement, the patient developed complete atrioventricular block and became pacemaker-dependent. A unique transvenous approach was utilized: the ventricular lead was advanced from the left axillary vein through the left subclavian vein, superior vena cava, right pulmonary artery, and main pulmonary artery into the right ventricle, resulting in successful left bundle branch pacing. This case illustrates an innovative strategy for permanent physiological pacing in post-Glenn patients.

BACKGROUND:Pacing-induced cardiomyopathy (PICM) is a serious complication associated with right ventricular pacing. This study aims to identify patients at a high risk for PICM and mitigate its incidence by guiding the selection of left bundle branch pacing over right ventricular pacing. METHODS:Consecutive patients who underwent permanent right ventricular pacing at two centers from January 2013 to December 2022 were retrospectively evaluated. They were used as the derivation set and the validation set, respectively. Clinical, echocardiographic, and electrocardiographic data were collected at baseline and during follow-up. Two models were developed using selected variables obtained through two different methods, and the superior model was chosen based on its simplicity and performance. Based on the selected model, a nomogram was constructed, evaluated, and externally validated using the validation set. RESULTS:The derivation set comprised 374 patients, with 74 (19.8%) diagnosed with PICM. The final Cox model incorporated ejection fraction, left ventricular end-systolic diameter, baseline QRS duration, and atrial fibrillation status (present/absent). The nomogram based on this model demonstrated moderate discrimination, achieving a C statistic of 0.75 (95% confidence interval: 0.70-0.81). The calibration curve showed accurate risk predictions for PICM. Its performance was consistent during internal validation via bootstrapping and was maintained in the validation set. The model effectively stratified risk, distinguishing between high-risk and low-risk populations. CONCLUSION:A user-friendly tool effectively predicts 3-, 5-, and 8-year risk of PICM in patients with right ventricular pacing and normal ejection fraction. It may help identify patients most likely to benefit from left bundle branch pacing versus right ventricular pacing, guiding initial pacing strategy selection.

ImportanceSuccess rates of pulmonary vein isolation (PVI) are modest for persistent atrial fibrillation (AF). Additional linear ablation beyond PVI has not been proved superior to PVI alone in randomized trials. Ethanol infusion of the vein of Marshall (EIVOM) facilitates ablation at the mitral isthmus and may lead to improved effectiveness of a linear ablation strategy.ObjectiveTo determine whether linear ablation with radiofrequency energy combined with EIVOM added to PVI improves sinus rhythm maintenance compared with PVI alone in patients with persistent AF.Design, Setting, and ParticipantsThe PROMPT-AF trial is an investigator-initiated, multicenter, open-label, randomized trial involving 12 tertiary hospitals in China. A total of 498 patients aged 18 to 80 years, with AF persisting for more than 3 months, undergoing first-time AF ablation, were enrolled and randomized from August 27, 2021, to July 16, 2023.InterventionsPatients were randomized to undergo PVI alone or PVI plus EIVOM and linear ablation (intervention). The latter group first underwent EIVOM, followed by PVI and linear ablation of the left atrial roof, mitral isthmus, and cavotricuspid isthmus.Main Outcomes and MeasuresThe primary end point was freedom from any documented atrial arrhythmias lasting more than 30 seconds, without the use of antiarrhythmic drugs within 12 months. Secondary outcomes included freedom from atrial arrhythmia recurrence, AF, atrial arrhythmia recurrence after multiple procedures, and documented atrial tachycardia or atrial flutter with or without antiarrhythmic drugs; AF burden; and improvement in quality of life. Patients were monitored with wearable single-lead electrocardiographic (ECG) patches, worn for 24 hours a week, supplemented by symptom-triggered ECGs and Holter monitoring.ResultsAmong 498 randomized patients, 495 (99.4%) were included in the primary analysis (mean age, 61.1 years [SD, 9.7] years, 361 male [72.9%]). After 12 months, 174 of 246 patients (70.7%) assigned to undergo PVI plus EIVOM and linear ablation and 153 of 249 patients (61.5%) assigned to undergo PVI alone remained free from atrial arrhythmias without taking antiarrhythmic drugs (hazard ratio, 0.73; 95% CI, 0.54-0.99, P = .045). The intervention effect was consistent across all prespecified subgroups. The comparison of secondary outcomes did not demonstrate significant results.ConclusionAmong patients with persistent AF, linear ablation combined with EIVOM in addition to PVI significantly improved freedom from atrial arrhythmias within 12 months compared with PVI alone.Trial RegistrationClinicalTrials.gov Identifier: NCT04497376

AIMS:Left bundle branch pacing is effective for cardiac resynchronization therapy (CRT), but the role of left ventricular septal pacing (LVSP) for CRT remains controversial due to lack of LBB capture. We hypothesized that combining LVSP with LV pacing (LVP) may provide additional benefits. METHODS AND RESULTS:This prospective observational study enrolled consecutive patients undergoing LVSP for CRT. LVSP was acceptable if paced QRS duration (QRSd)＜130 ms or QRSd reduction ≥ 20%. If neither criterion were met, a CS-LV lead was implanted. Acute hemodynamic response (AHR) represented by LV maximum first derivative (dP/dtmax) was accessed. All patients were followed up for echocardiographic parameters, NT-proBNP levels, NYHA classes, and clinical events. The clinical outcomes included all-cause mortality, heart failure hospitalization, and ventricular tachyarrhythmias. A total of 45 patients achieved left bundle branch area pacing (LBBAP) without confirmed LBB capture were enrolled, including 25 with LVSP alone and 20 with LVSP + LVP. QRSd reduction was significantly greater in LVSP + LVP than LVSP (46.2 ± 19.2 ms vs. 32.6 ± 23.0 ms, P = 0.049). LVSP + LVP resulted in greater improvement in AHR than LVSP (20.0 ± 9.2% vs. 10.4 ± 8.2%, P＜0.001) in 10 patients. After a median follow-up of 26-month, LVEF improvement was significantly higher in LVSP + LVP than LVSP (mean difference: 3.05%; 95% CI: 0.05-6.05; P = 0.047). LVSP + LVP was also independently associated with 87% lower risk of clinical outcomes compared with LVSP [aHR: 0.13 (0.03, 0.62), P = 0.011]. CONCLUSION:LVSP combined with LVP might offer greater AHR, electrical resynchronization and as well as improved clinical outcomes than LVSP alone in patients undergoing LBBAP-CRT without LBB capture.

BACKGROUND:Left bundle branch (LBB) pacing (LBBP) has been an emerging pacing modality that preserves physiological activation. However, data on the long-term durability of conduction system capture remain limited. In this study we aimed to assess the long-term stability of LBBP capture and identify predictors of capture loss. METHODS:We analyzed data from the multicentre, prospective Image Location and Performance of Left Bundle Branch Pacing (IMAGE-LBBP) cohort. Of 50 patients with bradycardia who underwent mid-term cardiac computed tomography imaging after left bundle branch area pacing implantation, 34 with confirmed LBBP and analyzable imaging at mid-term were included in the long-term analysis. Data on lead-related complications and pacing parameters were prospectively collected. The main outcome was new-onset loss of LBB capture after the mid-term assessment. RESULTS:During a mean follow-up of 60.1 ± 7.9 months, new-onset LBB capture loss occurred in 20.6% (7/34) of patients. Multivariate Cox regression identified mid-term lead tip to left ventricular cavity (Tip-LV) distance as an independent predictor of long-term capture loss (hazard ratio, 2.26; 95% confidence interval [CI], 1.17-4.35; P = 0.015). A cutoff of 2.0 mm yielded high predictive accuracy (area under the receiver operating characteristic curve, 0.881; 95% CI, 0.756-1.0), with 85.7% sensitivity and 77.8% specificity. Kaplan-Meier analysis showed a significantly greater risk of capture loss in patients with a Tip-LV distance > 2 mm compared with those with ≤ 2 mm (hazard ratio, 7.4; 95% CI, 1.6-34.8; log rank P = 0.012). CONCLUSIONS:LBB capture loss is progressive and occurs in approximately 20% of patients during long-term follow-up. A Tip-LV distance > 2 mm at mid-term is strongly associated with subsequent capture loss, highlighting the importance of optimal lead implantation and mid-term anatomical assessment to ensure durable conduction system pacing. CLINICAL TRIAL REGISTRATION:NCT04119323.

BACKGROUND:The segment of the latest mechanical contraction (LMC) does not always overlap with the site of the latest electrical activation (LEA). By integrating both mechanical and electrical dyssynchrony, this proof-of-concept study aimed to propose a new method for recommending left ventricular (LV) lead placements, with the goal of enhancing response to cardiac resynchronization therapy (CRT). METHODS:The LMC segment was determined by single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) phase analysis. The LEA site was detected by vectorcardiogram. The recommended segments for LV lead placement were as follows: (1) the LMC viable segments that overlapped with the LEA site; (2) the LMC viable segments adjacent to the LEA site; (3) If no segment met either of the above, the LV lateral wall was recommended. The response was defined as ≥15% reduction in left ventricular end-systolic volume (LVESV) 6-months after CRT. Patients with LV lead located in the recommended site were assigned to the recommended group, and those located in the non-recommended site were assigned to the non-recommended group. RESULTS:The cohort comprised of 76 patients, including 54 (71.1%) in the recommended group and 22 (28.9%) in the non-recommended group. Among the recommended group, 74.1% of the patients responded to CRT, while 36.4% in the non-recommended group were responders (P = .002). Compared to pacing at the non-recommended segments, pacing at the recommended segments showed an independent association with an increased response by univariate and multivariable analysis (odds ratio 5.00, 95% confidence interval 1.73-14.44, P = .003; odds ratio 7.33, 95% confidence interval 1.53-35.14, P = .013). Kaplan-Meier curves showed that pacing at the recommended LV lead position demonstrated a better long-term prognosis. CONCLUSION:Our findings indicate that pacing at the recommended segments, by integrating of mechanical and electrical dyssynchrony, is significantly associated with an improved CRT response and better long-term prognosis.

Background: For the initial treatment strategy for patients with cardiac resynchronization therapy (CRT) indications, whether to choose left bundle branch area pacing (LBBaP) or biventricular pacing (BVP) remains controversial. We aimed to investigate the cost-effectiveness ratio (CER) of LBBaP and BVP in heart failure (HF) patients with left bundle branch block (LBBB). Methods: This observational study included HF patients with LBBB who underwent successful LBBaP or BVP. The primary outcomes were echocardiographic response (left ventricular ejection fraction [LVEF] increase >= 5%), LVEF improvement, hospitalization costs, and CER (CER = cost/echocardiographic response rate). Secondary outcomes included other echocardiographic parameters, New York Heart Association (NYHA), N-terminal pro-B-type natriuretic peptide (NT-proBNP), pacemaker parameters, complications, ventricular arrhythmia (VA) events, HF hospitalization (HFH), and all-cause mortality. Results: A total of 130 patients (85 LBBaP and 45 BVP) were included (65.6 +/- 10.0 years, 70.77% men). The median follow-up period was 16(12,30), months. Compared with BVP, the LBBaP group showed a greater increase in LVEF (20.2% +/- 11.8% vs. 10.5% +/- 13.9%; p < 0.001), higher echocardiographic response rate (86.1% vs. 57.8%; p < 0.001), and lower hospitalization costs [$9707.7 (7751.2, 18,088.5) vs. $20,046.1 (18,840.1, 22,447.3); p < 0.0001]. The CER was 112.7 and 346.8 in LBBaP and BVP, respectively. The incremental cost-effectiveness ratio (ICER = Delta cost/Delta echocardiographic response rate) was $-365.3/per 1% increase in effectiveness. LBBaP improved cardiac function more significantly than BVP. There were no significant differences in clinical outcomes. Conclusions: LBBaP-CRT is more cost-effective than BVP, offering greater LVEF improvement, higher echocardiographic response rates, lower hospitalization costs, and more significantly improved cardiac function. These findings need large randomized clinical trials for further confirmation.

Background:Patients with recurrent massive pericardial effusion are at risk of recurrent cardiac tamponade. The current standard of care includes repeat pericardiocentesis or pericardial window when recurrent effusions cause haemodynamic compromise. Here, we report a case of a patient in whom an infusion port was used for drainage of recurrent pericardial effusion. Patient was followed up for 10 months demonstrating convenience and safety of use without evidence of cardiac tamponade. Case summary:We present a patient with recurrent massive pericardial effusion after previously undergoing two difficult pericardiocenteses of posteriorly located pericardial effusion causing tamponade. An infusion port was implanted and periodical follow-up and drainage through the port were performed. During follow-up, there was no evidence of tamponade caused by recurrence of pericardial effusion and no complications from the port. Discussion:Pericardiocentesis can be challenging in certain circumstances such as loculated or posteriorly located pericardial effusion. For patients with recurrent effusion, there is an incremental risk of serious complications with every pericardiocentesis. This case illustrates the feasibility of using an infusion port in recurrent pericardial effusion. After subcutaneous implantation of the infusion port, repeat pericardiocentesis and its related complications were avoided. Later pericardial decompression and intrapericardial administration of medications were simple and safe by accessing the port top.