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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

Left ventricular or biventricular pacing improves cardiac function at diminished energy cost in patients with dilated

G S Nelson1, R D Berger, B J Fetics

  • 1Division of Cardiology, Department of Medicine, The Johns Hopkins Medical Institutions, Baltimore, MD, USA.

Circulation
|January 11, 2000
PubMed

Insights

Left ventricular or biventricular pacing improves systolic function in dilated cardiomyopathy patients without increasing myocardial oxygen consumption. This cardiac resynchronization therapy offers a valuable treatment strategy for heart failure with dyssynchrony.

Area of Science:

  • Cardiology
  • Heart Failure Research
  • Biomedical Engineering

Background:

  • Dilated cardiomyopathy (DCM) patients with conduction delays experience improved systolic function via ventricular pacing.
  • Conventional therapies enhancing systolic function often increase myocardial oxygen demand.
  • This study investigated if ventricular pacing offers systolic benefits without increasing energy demand.

Purpose of the Study:

  • To determine if left ventricular or biventricular pacing in DCM patients with left bundle-branch block enhances systolic function.
  • To assess the impact of ventricular pacing on myocardial oxygen consumption (MVO(2)) compared to dobutamine.

Main Methods:

  • Cardiac catheterization in 10 DCM patients to measure hemodynamic parameters and MVO(2) during sinus rhythm and pacing.
  • Comparison of pacing effects with dobutamine infusion in 7 DCM patients.
  • Measurements included ventricular/aortic pressure, coronary blood flow, and arterial-coronary sinus oxygen difference (DeltaAVO(2)).

Main Results:

  • Left ventricular (LV) pacing significantly increased systolic function (arterial pulse pressure, dP/dt(max)) in DCM patients.
  • LV pacing led to a decrease in DeltaAVO(2) and MVO(2), indicating reduced energy cost.
  • Dobutamine increased systolic function but also significantly raised MVO(2) compared to pacing.

Conclusions:

  • Ventricular resynchronization via LV or biventricular pacing acutely enhances systolic function in DCM patients with left bundle-branch block.
  • Pacing therapy modestly lowers myocardial energy cost, unlike dobutamine.
  • This approach is a promising treatment for DCM patients suffering from basal dyssynchrony.
Abstract

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