Initial experience, feasibility and safety of permanent left bundle branch pacing: results from a prospective single-centre study

Background Left bundle branch (LBB) pacing is a novel pacing technique which may serve as an alternative to both right ventricular pacing for symptomatic bradycardia and cardiac resynchronisation therapy (CRT). A substantial amount of data is reported by relatively few, highly experienced centres. This study describes the first experience of LBB pacing in a high-volume device centre. Methods Success rates (i.e. the ability to achieve LBB pacing), electrophysiological parameters and complications at implant and up to 6 months of follow-up were prospectively assessed in 100 consecutive patients referred for various pacing indications. Results The mean age was 71 ± 11 years and 65% were male. Primary pacing indication was atrioventricular (AV) block in 40%, CRT in 42%, and sinus node dysfunction or refractory atrial fibrillation prior to AV node ablation in 9% each. Baseline left ventricular ejection fraction was < 50% in 57% of patients, mean baseline QRS duration 145 ± 34 ms. Overall LBB pacing was successful in 83 of 100 (83%) patients but tended to be lower in patients with CRT pacing indication (69%, p = ns). Mean left ventricular activation time (LVAT) during LBB pacing was 81 ms and paced QRS duration was 120 ± 19 ms. LBB capture threshold and R‑wave sense at implant was 0.74 ± 0.4 mV at 0.4 ms and 11.9 ± 5.9 V and remained stable at 6‑month follow-up. No complications occurred during implant or follow-up. Conclusion LBB pacing for bradycardia pacing and resynchronisation therapy can be easily adopted by experienced implanters, with favourable success rates and safety profile.

Surgical epicardial left ventricular lead implantation as a troubleshooting step for a left ventricular lead fracture following difficult transvenous implants in cardiac resynchronisation therapy patients: a case report

Troubleshooting of left ventricular (LV) lead fractures in cardiac resynchronisation therapy patients is important, especially for those with limited and problematic transvenous LV lead placement. In this case, surgical epicardial LV lead implantation was employed.

Cardiac resynchronisation therapy in a pace-dependent infant with tetralogy of Fallot

We present the case of a 5-month-old infant with tetralogy of Fallot and congenital atrio-ventricular block that developed severe left ventricular dysfunction during apical left ventricular pacing, in which cardiac resynchronisation therapy was used as an emergency procedure due to persistent low cardiac output syndrome.

Prevalence of left bundle branch block and CRT treatment in a large regional unselected ECG database

Introduction Heart failure is a clinical syndrome in which signs and symptoms are due to functional and/or structural abnormalities of the heart which prevent the necessary supply of oxygenated blood or do so at the expense of high filling pressures. It has a prevalence of 1–2% in the western world and increasing prevalence with increasing age. While the prognosis for coronary heart disease has improved significantly, the same does not apply for heart failure, perhaps because some effective treatment methods have not been sufficiently implemented in health care. One effective but underutilized heart failure treatment is the cardiac resynchronisation therapy (CRT), that coordinates the contraction of the left and right ventricles via a pacemaker (PM). CRT treatment is an evidence based treatment recommended by among other the ESC guidelines for heart failure. Clinical studies have suggested decreases in mortality, hospitalization, morbidity and improvements in quality of life for heart failure patients receiving a CRT. Purpose To find a new clinical pathway to improve CRT implementation and to evaluate if it might be optimized through ECG-based surveillance and thus improving prognosis. Methods In a population of approximately 2.5 million people in our region we investigated the University Hospital's ECG database between 2000 and 2018. During which time 432 108 adult patients with 1 482 489 ECG's presented to the hospital. We searched and found 5 511 unique patients with the following ECG criteria: QRS ≥150 ms at any time, LBBB and Non pace. According to the Pacemaker Registry we excluded 771 patients that had previously received a PM/CRT. We also identified patients with diagnosis of heart failure by using the ICD-10 codes (I42.0 and I50). Results Our final cohort consists of 4 740 patients. The median age was 75 (19–112) years, 34.5% were female and 14.9% were subsequently implanted with a CRT (60% with CRT-D). The median time to CRT implantation from the first ECG with LBBB was 244 (IQR 994) days. Of the 4 740 patients 20.6% had a previous hospitalistion for heart failure with a median delay from the hospitalisation to CRT implantation of 5 (IQR 5.4) years. Conclusions Our observational data from a large real-life regional ECG database show there is a considerable number of heart failure patients that could benefit from CRT treatment. Using an existing ECG database could be useful in finding patients with indication for CRT implantation. This could possibly influence morbidity and mortality in a regional heart failure population by minimizing the delay of CRT treatment. FUNDunding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Karolinska University Hospital Research Fund

Advanced image-supported lead placement in cardiac resynchronisation therapy: protocol for the multicentre, randomised controlled ADVISE trial and early economic evaluation

IntroductionAchieving optimal placement of the left ventricular (LV) lead in cardiac resynchronisation therapy (CRT) is a prerequisite in order to achieve maximum clinical benefit, and is likely to help avoid non-response. Pacing outside scar tissue and targeting late activated segments may improve outcome. The present study will be the first randomised controlled trial to compare the efficacy of real-time image-guided LV lead delivery to conventional CRT implantation. In addition, to estimate the cost-effectiveness of targeted lead implantation, an early decision analytic model was developed, and described here.Methods and analysisA multicentre, interventional, randomised, controlled trial will be conducted in a total of 130 patients with a class I or IIa indication for CRT implantation. Patients will be stratified to ischaemic heart failure aetiology and 1:1 randomised to either empirical lead placement or live image-guided lead placement. Ultimate lead location and echocardiographic assessment will be performed by core laboratories, blinded to treatment allocation and patient information. Late gadolinium enhancement cardiac magnetic resonance imaging (CMR) and CINE-CMR with feature-tracking postprocessing software will be used to semi-automatically determine myocardial scar and late mechanical activation. The subsequent treatment file with optimal LV-lead positions will be fused with the fluoroscopy, resulting in live target-visualisation during the procedure. The primary endpoint is the difference in percentage of successfully targeted LV-lead location. Secondary endpoints are relative percentage reduction in indexed LV end-systolic volume, a hierarchical clinical endpoint, and quality of life. The early analytic model was developed using a Markov-model, consisting of seven mutually exclusive health states.Ethics and disseminationThe protocol was approved by the Medical Research Ethics Committee Utrecht (NL73416.041.20). All participants are required to provide written informed consent. Results will be submitted to peer-reviewed journals.Trial registration numberNCT05053568; Trial NL8666.