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Updated: May 15, 2026

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
12:45

Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing

Published on: December 11, 2017

Larger interventricular conduction time enhances mechanical response to resynchronization therapy

Luigi Padeletti1, Paolo Pieragnoli, Giuseppe Ricciardi

  • 1Institute of Internal Medicine and Cardiology, University of Florence, Florence, Italy. lpadeletti@interfree.it

Pacing and Clinical Electrophysiology : PACE
|January 12, 2013
PubMed

Insights

Optimizing cardiac resynchronization therapy (CRT) involves finding the best left ventricular (LV) pacing site. Measuring right ventricular (RV)-to-LV conduction time helps identify optimal LV lead placement for improved systolic function.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Devices

Background:

  • Left ventricular (LV) pacing site significantly impacts hemodynamic response in cardiac resynchronization therapy (CRT).
  • Current lead positioning in lateral or posterolateral cardiac veins may not be universally optimal.
  • Individualized LV lead placement is crucial for effective CRT.

Purpose of the Study:

  • To evaluate the relationship between right ventricular (RV)-to-LV conduction time and systolic function during CRT.
  • To assess if RV-to-LV conduction time can predict optimal LV pacing site.
  • To analyze changes in LV pressure-volume loops based on pacing site and AV delay.

Main Methods:

  • Utilized conductance catheter to measure LV pressure and volume in 10 patients during CRT implantation.
  • Systematically assessed four endocardial LV sites across four atrioventricular delays.
  • Measured RV-to-LV conduction time as the interval between spontaneous peak R waves from RV lead and LV catheter.

Main Results:

  • Optimal pacing site varied among patients.
  • Pacing at the site with maximum RV-to-LV conduction time yielded stroke volume improvement comparable to individually optimized sites (41 ± 17 mL vs 44 ± 18 mL, P = 0.266).
  • RV-to-LV conduction time positively correlated with increases in stroke volume (r = 0.537), stroke work (r = 0.642), and pressure-derivative maximum (r = 0.646).

Conclusions:

  • Optimal acute CRT response can be achieved by placing the LV lead at the site with maximum RV-to-LV conduction time.
  • A significant correlation exists between RV-to-LV conduction time and CRT-induced systolic function improvement.
  • RV-to-LV conduction time serves as a valuable predictor for LV lead positioning in CRT.
Abstract

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