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Increased dispersion and shortened refractoriness caused by verapamil in chronic atrial fibrillation

H Ramanna1, A Elvan, F H Wittkampf

  • 1Heart-Lung Institute, University Medical Center, Utrecht, Netherlands.

Journal of the American College of Cardiology
|April 13, 2001
PubMed

Insights

Verapamil shortened refractoriness but increased spatial dispersion in patients with chronic atrial fibrillation (AF). These findings suggest verapamil is not effective for reversing AF remodeling.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Pharmacology

Background:

  • Previous research indicated verapamil may prevent acute atrial fibrillation (AF) remodeling.
  • The impact of verapamil on chronic AF remodeling remained uninvestigated.

Purpose of the Study:

  • To evaluate verapamil's effects on atrial fibrillation cycle length.
  • To assess verapamil's impact on spatial dispersion of refractoriness in chronic AF patients.

Main Methods:

  • Electrophysiologic studies were conducted on 15 patients with chronic AF (>1 year).
  • Unipolar electrograms and monophasic action potentials were recorded.
  • Refractoriness and its spatial dispersion were measured before and after verapamil administration.

Main Results:

  • Verapamil significantly shortened mean fibrillatory intervals across multiple atrial sites.
  • Monophasic action potential duration decreased post-verapamil.
  • A significant increase in spatial dispersion of refractoriness was observed.

Conclusions:

  • Verapamil administration led to shortened refractoriness and increased spatial dispersion in chronic AF.
  • These results indicate verapamil is unlikely to be beneficial in reversing AF remodeling.
Abstract

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