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Dose-response relationship for successful internal atrial defibrillation

Hung-Fat Tse1, Chu-Pak Lau, Gregory M Ayers

  • 1Cardiology Division, Department of Medicine, University of Hong Kong, Queen Mary Hospital, Hong Kong, China. hftse@hkucc.hku.hk

Pacing and Clinical Electrophysiology : PACE
|May 27, 2003
PubMed

Insights

This study establishes the dose-response relationship for internal atrial defibrillation in humans, revealing significant differences between acute and chronic atrial fibrillation (AF) for effective shock delivery.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Medical Devices

Background:

  • The dose-response relationship for ventricular defibrillation is known, but not for atrial defibrillation in humans.
  • Atrial fibrillation (AF) affects a significant portion of the population, necessitating effective treatment strategies.

Purpose of the Study:

  • To determine the dose-response relationship for internal atrial defibrillation in human patients.
  • To compare the efficacy of defibrillation for acute versus chronic AF.

Main Methods:

  • Seventy-seven patients with acute or chronic AF underwent internal atrial defibrillation.
  • Shock strength was incrementally increased, and success was analyzed using Kaplan-Meier survival and nonparametric probability analyses.
  • Dose-response relationships were established, and shock intensities for specific conversion percentages (20-95%) were estimated.

Main Results:

  • Significant dose-response relationships were found for both acute and chronic AF (P < 0.05).
  • Kaplan-Meier analysis revealed significant differences in dose-response relationships between acute and chronic AF (P < 0.001).
  • Estimated shock intensity for 95% conversion was 279 V (2.9 J) for acute AF and 433 V (6.6 J) for chronic AF (P < 0.001).

Conclusions:

  • Single shock conversion data can effectively determine atrial defibrillation dose-response relationships.
  • This relationship allows for the estimation of required shock intensities for specific efficacy levels.
  • The findings highlight the impact of AF chronicity on defibrillation efficacy, informing treatment strategies.

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