The goals of this research project are directed toward a better understanding of the electrophysiologic mechanisms underlying the rhythmic disturbances in the ischemic heart which lead to ventricular fibrillation in the conscious, ambulatory animal or to reentrant arrhythmias in response to programmed electrical stimulation. The electrophysiologic testing techniques and the animal model of spontaneous ventricular fibrillation will permit us to critically evaluate the various classes of antiarrhythmic drugs with respect to their ability to prevent life threatening arrhythmias and/or sudden coronary death. Because of the similarity in response to the clinical use of programmed electrical stimulation, the exprimental canine model offers a promising approach to the evaluation of antiarrhythmic and antifibrillatory drugs. The studies proposed in the chronically ischemic canine heart will have great potential in the preclinical evaluation of pharmacologic interventions for prophylactic use in patients at high risk of developing out-of-hospital ventricular fibrillation. The studies for the current year will concentrate on an evaluation of antiarrhythmic agents belonging to Class III and IV which will be compared to some of the newer Class I drugs for their efficacy in preventing ventricular fibrillation in the dog with chronic myocardial ischemic injury.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL005806-26
Application #
3334189
Study Section
Pharmacology A Study Section (PHRA)
Project Start
1978-01-01
Project End
1987-12-31
Budget Start
1986-01-01
Budget End
1986-12-31
Support Year
26
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Type
Schools of Medicine
DUNS #
791277940
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Friedrichs, G S; Chi, L; Black, S C et al. (1994) Antiarrhythmic agent, MS-551, protects against pinacidil + hypoxia-induced ventricular fibrillation in Langendorff-perfused rabbit isolated heart. J Cardiovasc Pharmacol 23:120-6
Chi, L; Friedrichs, G S; Oh, J Y et al. (1994) Effect of Ado A1- and A2-receptor activation on ventricular fibrillation during hypoxia-reoxygenation. Am J Physiol 267:H1447-54
Friedrichs, G S; Chi, L; Green, A L et al. (1994) Antifibrillatory effects of clofilium in the rabbit isolated heart. Br J Pharmacol 113:209-15
Black, S C; Butterfield, J L; Lucchesi, B R (1993) Protection against programmed electrical stimulation-induced ventricular tachycardia and sudden cardiac death by NE-10064, a class III antiarrhythmic drug. J Cardiovasc Pharmacol 22:810-8
Chi, L; Black, S C; Kuo, P I et al. (1993) Actions of pinacidil at a reduced potassium concentration: a direct cardiac effect possibly involving the ATP-dependent potassium channel. J Cardiovasc Pharmacol 21:179-90
Black, S C; Fagbemi, S O; Chi, L et al. (1993) Phorbol ester-induced ventricular fibrillation in the Langendorff-perfused rabbit heart: antagonism by staurosporine and glibenclamide. J Mol Cell Cardiol 25:1427-38
Lucchesi, B R; Chi, L; Friedrichs, G S et al. (1993) Antiarrhythmic versus antifibrillatory actions: inference from experimental studies. Am J Cardiol 72:25F-44F
Fagbemi, S O; Chi, L; Lucchesi, B R (1993) Antifibrillatory and profibrillatory actions of selected class I antiarrhythmic agents. J Cardiovasc Pharmacol 21:709-19
Friedrichs, G S; Chi, L; Black, S C et al. (1993) Antifibrillatory effects of ibutilide in the rabbit isolated heart: mediation via ATP-dependent potassium channels. J Pharmacol Exp Ther 266:1348-54
Chi, L G; Mu, D X; Lucchesi, B R (1991) Electrophysiology and antiarrhythmic actions of E-4031 in the experimental animal model of sudden coronary death. J Cardiovasc Pharmacol 17:285-95

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