The work was supported in part by an American Heart Association Scientist Development Grant and The National Institutes of Health Research Grants HL-28429, HL-66256, and HL-85370.
Effects of Procainamide and Sotalol on Restitution Properties, Dispersion of Refractoriness, and Ventricular Fibrillation Activation Patterns in Pigs
Article first published online: 9 MAY 2008
© 2008 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 19, Issue 10, pages 1090–1097, October 2008
How to Cite
JIN, Q., CHEN, X., SMITH, W. M., IDEKER, R. E. and HUANG, J. (2008), Effects of Procainamide and Sotalol on Restitution Properties, Dispersion of Refractoriness, and Ventricular Fibrillation Activation Patterns in Pigs. Journal of Cardiovascular Electrophysiology, 19: 1090–1097. doi: 10.1111/j.1540-8167.2008.01200.x
Manuscript received 30 October 2007; Revised manuscript received 17 March 2008; Accepted for publication 18 March 2008.
- Issue published online: 20 SEP 2008
- Article first published online: 9 MAY 2008
- ventricular fibrillation;
- activation patterns
Background: Interest in combining antiarrhythmic drugs has been prompted by the lack of efficacy of monotherapies and the toxicity resulting from high doses of individual agents.
Objectives: We tested the hypothesis that procainamide and sotalol combined have greater beneficial effects on restitution, on the dispersion of refractoriness, and on decreasing the complexity of ventricular fibrillation (VF) than either drug alone.
Methods: Six open-chest pigs received intravenous procainamide (15 mg/kg load and 50 μg/kg/min maintenance) followed by sotalol (1.5 mg/kg). Another six pigs received sotalol first and procainamide second. Before drugs and after each drug, 20-second episodes of electrically induced VF were recorded from a 21 × 24 unipolar electrode plaque (2 mm spacing) sutured on the lateral posterior left ventricular epicardium. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals during pacing.
Results: The combination of the two drugs reduced the maximum slope of the restitution curve and during VF reduced the number of wavefronts, the activation rate, the percentage of wavefront families exhibiting reentry, and the conduction velocity more than either drug alone. In addition, in the group that received sotalol first, both drugs together reduced the SD and the coefficient of variation of the spatial dispersion of refractoriness compared with baseline.
Conclusions: Procainamide and sotalol combined have greater beneficial effects on restitution properties, dispersion of refractoriness, and the complexity of VF than either drug alone compared with baseline.