Abstract Objectives The aim of this study was to compare the volumetric response and the long-term survival after cardiac resynchronization therapy (CRT) in patients with intrinsic left bundle branch ...block (LBBB) versus chronic right ventricular pacing (RVP) with respect to the presence of mechanical dyssynchrony (MD). Background Chronic RVP induces an iatrogenic LBBB and asynchronous left ventricular contraction that is potentially reversible by upgrading to CRT. Methods A total of 914 patients eligible for CRT (117 with conventional pacemakers and 797 with intrinsic LBBB) were included in the study. MD was visually assessed before CRT and was defined as the presence of either apical rocking and/or septal flash on baseline echocardiograms. Patients with a left ventricular end-systolic volume decrease of ≥15% during the follow-up were considered responders. Patients were followed for all-cause mortality during the median follow-up of 48 months (interquartile range: 29 to 66 months). Results MD was observed in 51% of patients with RVP versus 77% in patients with intrinsic LBBB (p < 0.001). Patients with RVP and MD had a similar likelihood of volumetric response as did patients with intrinsic LBBB and MD (adjusted odds ratio: 0.71; 95% confidence interval: 0.33 to 1.53; p = 0.385). There was no significant difference in long-term survival between patients with RVP and intrinsic LBBB (adjusted hazard ratio: 1.101; 95% confidence interval: 0.658 to 1.842; p = 0.714). Patients with visual MD and either intrinsic LBBB or RVP had a more favorable survival than those without MD (p < 0.001). Conclusions The likelihood of volumetric response and a favorable long-term survival of patients with RVP was similar to those of patients with intrinsic LBBB and were mainly determined by the presence of MD and not by the nature of LBBB.
BACKGROUND—Left ventricular septal (LVS) pacing reduces ventricular dyssynchrony and improves cardiac function relative to right ventricular apex (RVA) pacing in animals. We aimed to establish ...permanent placement of an LVS pacing lead in patients using a transvenous approach through the interventricular septum.
METHODS AND RESULTS—Ten patients with sinus node dysfunction scheduled for dual-chamber pacemaker implantation were prospectively enrolled. A custom pacing lead with extended helix was introduced via the left subclavian vein and, after positioning against the right ventricular septum (RVS) using a preshaped guiding catheter, driven through the interventricular septum to the LVS. The acute hemodynamic effect of RVA, RVS, and LVS pacing was evaluated by invasive LVdP/dtmax measurements. The lead was successfully delivered to the LVS in all patients. Procedure time and fluoroscopy time shortened with experience. QRS duration was shorter during LVS pacing (144±20 ms) than during RVA (172±33 ms; P=0.02 versus LVS) and RVS pacing (165±17 ms; P=0.004 versus LVS). RVA and RVS pacing reduced LVdP/dtmax compared with baseline atrial pacing (−7.1±4.1% and −6.9±4.3%, respectively), whereas LVS pacing maintained LVdP/dtmax at baseline level (1.0±4.3%; P=0.001 versus RVA and RVS). R-wave amplitude and pacing threshold were 12.2±6.7 mV and 0.5±0.2 V at implant and remained stable during 6-month follow-up without lead-related complications.
CONCLUSIONS—Permanent placement of an LVS pacing lead by transvenous approach through the interventricular septum is feasible in patients. LVS pacing preserves acute left ventricular pump function. This new pacing method could serve as an alternative and hemodynamically preferable approach for antibradycardia pacing.
This report demonstrates the feasibility of pacing the left bundle branch (LBB) immediately beyond the conduction block to functionally restore the impaired His-Purkinje conduction system in a ...patient with heart failure and left bundle branch block (LBBB). The pacing required only a low pacing output (0.5 volts/0.5 ms) to correct the LBBB with accompanying right BBB on the electrocardiogram. Over 1-year of follow-up, the patient had a significant improvement in clinical outcome and echocardiographic measurements. The case shows a novel pacing strategy for patients with BBB that affects many patients with heart failure.
Le présent rapport démontre la faisabilité de la stimulation de la branche gauche (BG) immédiatement après le bloc de conduction pour restaurer de manière fonctionnelle le système de conduction de His et Purkinje chez un patient qui présente une insuffisance cardiaque et un bloc de branche gauche (BBG). La stimulation a seulement exigé une faible sortie de stimulation (0,5 volts/0,5 ms) pour corriger le BBG associé au BB droit à l’électrocardiogramme. Au cours du suivi de 1 an, le patient a connu une nette amélioration des résultats cliniques et des mesures échocardiographiques. Ce cas montre une nouvelle stratégie de stimulation chez les patients présentant un BB (qui touche un grand nombre de patients atteints d’insuffisance cardiaque).
Left bundle branch pacing (LBBP) involves the deployment of the lead deep inside the septum. Penetration of the septum by the lead depends on the texture of the septum, rapidity of rotations, ...operator experience, and implantation tools.
The aim of our study was to assess the behavior of the lumenless lead during rapid rotations and the physiological property of the interventricular septum(IVS) during LBBP.
Patients undergoing LBBP between January 2021 and December 2022 were retrospectively included in the study.
Among 255 attempted patients, 20 (7.9%) had procedural failure(no LBB capture-four, inability to penetrate septum-seven, and dislodgements after sheath removal-nine). Septal penetration achieved in 248/255 patients (97.2%). Lead movement inside the IVS was assessed by lead traverse time. Based on the behavior of the IVS (n = 255), three different responses were noted. Type-I response(normal/firm septum) in 93.7% (n = 239) characterized by constant and progressive movement of lead. Neither perforation nor further change in premature-ventricular-complex morphology beyond M-beat were observed despite additional few unintentional rotations indicating the protective mechanism of LV-endocardium. Type-II response(soft/cheesy septum) in 3.5% (n = 9) characterized by hyper-movement of lead without resistance due to altered texture of septum and poor LV subendocardial barrier resulting in perforation. No patients in this group had LV dysfunction or associated coronary artery disease. In type-III response, seen in 2.8% (n = 7), lead could not be penetrated due to scar in IVS.
Three different patterns of responses were observed during LBBP. The most distinct type-ll response was associated with soft/cheesy septum with hyper-movement of the lead predisposing for future dislodgments in patients without structural heart disease.
Abstract
Aims
This study aims to determine procedural characteristics, acute success rates, and medium-term outcomes of consecutive patients undergoing His bundle pacing (HBP); and learning curves of ...experienced electrophysiologists adopting HBP.
Methods and results
Consecutive HBP patients at three hospitals were recruited. Clinical characteristics, acute procedural details, and medium-term outcomes were extracted from electronic medical records. Two hundred and thirty-three patients mean age 74.6 ± 10.1 years, 48% female, 68% narrow QRS, 71% normal left ventricular ejection fraction (LVEF), 55.8% atrioventricular block underwent HBP. Acute procedural success was 81.1% (mean procedural and fluoroscopic times of 105.5 ± 36.5 and 13.8 ± 9.3 min). Broad QRS was associated with lower HBP success (odds ratio 0.39, P = 0.02). Fluoroscopic and procedural times decreased and plateaued after 30–40 cases per operator. Implant HBP threshold was 1.3 ± 0.7 V at 1.0 ± 0.2 ms and R wave was 5.0 ± 3.9 mV. During follow-up, loss of HBP occurred in a further 12.4% and 11.3% of patients experienced a ≥1 V increase in HBP threshold. Five (2.6%) patients required HBP revision for pacing difficulties. About 8.6% of patients had a >50% decrease in R wave but lead revision for sensing issues was not necessary. On an intention to treat basis, 56.7% of patients in whom HBP was attempted had persisting HBP capture and thresholds of <2 V.
Conclusion
Physicians adopting HBP should be cognizant of the learning curve and preferentially select non-dependent patients with normal QRS and LVEF, to minimize risk of lead revision. Further rises in HBP threshold may increase battery drain and need for reoperations, important considerations when choosing HBP for cardiac resynchronization therapy.
In this comparative-effectiveness trial, biventricular pacing prevented the reduction in left ventricular ejection fraction that is seen with right ventricular pacing.
The deleterious effect of ...nonphysiologic right ventricular apical pacing on left ventricular systolic function has been recognized since the 1920s.
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In the Dual Chamber and VVI Implantable Defibrillator (DAVID) trial, the unexpected increased rates of death and hospital admission for heart failure among patients who were randomly assigned to the dual-chamber, rate-adaptive (DDDR) mode were purportedly due to the adverse effect of right ventricular apical pacing on left ventricular structural remodeling.
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Results of subsequent trials have supported the notion that right ventricular apical pacing might lead to adverse clinical outcomes in patients with standard pacing indications.
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Nevertheless, right ventricular . . .
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