Terikalant and barium decrease the area of vulnerability to ventricular fibrillation induction by T-wave shocks.

Abstract

The area of vulnerability (AOV) to ventricular fibrillation (VF) induction by high-voltage shocks has been proposed as a measure of vulnerability to VF. Biphasic shocks spanning the T wave and ranging between 50 V and the upper limit of vulnerability (ULV) to VF were delivered before and after terikalant (1 mg/kg) and barium (1.1 mg/kg load followed by 0.05-0.10 mg/kg/min maintenance) or vehicle in dogs. The AOV decreased by 34% and 28% (p < 0.01) after terikalant and barium (n = 8 dogs each), respectively. Mean ULV, defibrillation threshold (DFT), and ventricular vulnerability period (VVP) decreased by 16%, 23%, and 31% (p < 0.01), respectively, after terikalant, and by 25%, 17% (p < 0.01), and 13% (p = 0.08), respectively, after barium. Vehicle (n = 14) did not significantly alter any of these variables. The ULV was correlated with the DFT before and after terikalant (r = 0.78, p < 0.01) and barium (r = 0.83, p < 0.01). Potassium channel blockers of the current reduce the ability to induce VF; this effect may be related to the anti-fibrillatory action of class III anti-arrhythmic drugs and their ability to decrease DFT.

• Authors: Xiangqian Qi, Pryam Varma, David Newman, Nikolaos Mamalias, Paul Dorian
• Journal: Journal of cardiovascular pharmacology (J Cardiovasc Pharmacol) Vol. 39 Issue 2 Pg. 242-50 (Feb 2002) ISSN: 0160-2446 [Print] United States
• PMID: 11791010 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Arrhythmia Agents
• Barium Compounds
• Chlorides
• Chromans
• Piperidines
• barium chloride
• terikalant

Topics

• Action Potentials (drug effects)
• Animals
• Anti-Arrhythmia Agents (pharmacology)
• Barium Compounds (pharmacology)
• Chlorides (pharmacology)
• Chromans (pharmacology)
• Dogs
• Electric Countershock
• Electrocardiography
• Female
• Infusions, Intravenous
• Male
• Piperidines (pharmacology)
• Ventricular Fibrillation (etiology, physiopathology)
• Ventricular Function (drug effects)