This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ben-David, J. Articles by Zipes, D. P. Search for Related Content PubMed PubMed Citation Articles by Ben-David, J. Articles by Zipes, D. P.

Circulation, Vol 82, 225-233, Copyright © 1990 by American Heart Association

ARTICLES

Alpha-adrenoceptor stimulation and blockade modulates cesium-induced early afterdepolarizations and ventricular tachyarrhythmias in dogs

J Ben-David and DP Zipes
Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis 46202.

In 84 open-chest dogs, we studied the effects on early afterdepolarizations (EADs) and ventricular tachyarrhythmias (VTs) induced by cesium chloride (168 mg/kg i.v.) of alpha-adrenoceptor stimulation with phenylephrine (100 micrograms plus 0.25 microgram/kg/min i.v.) and with left ansa subclavia stimulation (LAS; 2 Hz, 4 msec, 2 mA) after propranolol (0.5 mg/kg) administration. We also studied the effects of alpha-adrenoceptor blockade with phentolamine (3 mg/kg), prazosin (25-500 micrograms/kg), yohimbine (10-500 micrograms/kg), WB 4101 (2 mg/kg), and benoxathian (2 mg/kg) during decentralized LAS. EAD amplitude, presented as a percentage of monophasic action potential amplitude, was recorded simultaneously with contact electrodes from the right and left ventricular endocardium. Phenylephrine and LAS plus propranolol increased EAD amplitude (31.5 +/- 8.8% to 47.8 +/- 9.7% and 34.8 +/- 4.1% to 46.1 +/- 6.4%, respectively) and the prevalence of VT (from three to nine of 11 dogs and from the three to five of six dogs, respectively). Prazosin produced a dose- response decrease in EAD amplitude and reduced the prevalence of VT. Yohimbine did not alter the amplitude of EADs or the prevalence of VT. WB 4101 and phentolamine reduced the amplitude of EADs produced by cesium and LAS (from 44.3 +/- 10.2% to 32.6 +/- 9.4% and from 39.8 +/- 6.9% to 30.3 +/- 6.3%, respectively) and the prevalence of VT (from eight to one of 10 dogs and from 13 to 5 of 20 dogs, respectively). Benoxathian did not alter significantly the amplitude of EADs (41.6 +/- 11.4% to 37.5 +/- 9.4%) or the prevalence of VT (from six to five of 10 dogs).(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				H. Morita, D. P. Zipes, S. T. Morita, and J. Wu Mechanism of U wave and polymorphic ventricular tachycardia in a canine tissue model of Andersen-Tawil syndrome Cardiovasc Res, August 1, 2007; 75(3): 510 - 518. [Abstract] [Full Text] [PDF]

				R. L. Hamlin A Search to Predict Potential for Drug-Induced Cardiovascular Toxicity Toxicol Pathol, January 1, 2006; 34(1): 75 - 80. [Abstract] [Full Text] [PDF]

				S. Viskin, R. Fish, A. Roth, P. J. Schwartz, and B. Belhassen QT or Not QT? N. Engl. J. Med., August 3, 2000; 343(5): 352 - 356. [Full Text] [PDF]

				P. G.A. Volders, M. A. Vos, B. Szabo, K. R. Sipido, S.H.M. de Groot, A. P.M. Gorgels, H. J.J. Wellens, and R. Lazzara Progress in the understanding of cardiac early afterdepolarizations and torsades de pointes: time to revise current concepts Cardiovasc Res, June 1, 2000; 46(3): 376 - 392. [Full Text] [PDF]

				E. A Sosunov, E. P Anyukhovsky, A. Shvilkin, Motoki Hara, S. F Steinberg, P. Danilo Jr., M. R Rosen, N Sydney Moise, J. Merot, V. Probst, et al. Abnormal cardiac repolarization and impulse initiation in German shepherd dogs with inherited ventricular arrhythmias and sudden death Cardiovasc Res, April 1, 1999; 42(1): 65 - 79. [Abstract] [Full Text] [PDF]

				L. Eckardt, W. Haverkamp, M. Borggrefe, and G. Breithardt Experimental models of torsade de pointes Cardiovasc Res, July 1, 1998; 39(1): 178 - 193. [Abstract] [Full Text] [PDF]

				G. Gambassi, H. A. Spurgeon, B. D. Ziman, E. G. Lakatta, and M. C. Capogrossi Opposing effects of alpha 1-adrenergic receptor subtypes on Ca2+ and pH homeostasis in rat cardiac myocytes Am J Physiol Heart Circ Physiol, April 1, 1998; 274(4): H1152 - H1162. [Abstract] [Full Text] [PDF]

				D. M. Roden, R. Lazzara, M. Rosen, P. J. Schwartz, J. Towbin, and G. M. Vincent Multiple Mechanisms in the Long-QT Syndrome: Current Knowledge, Gaps, and Future Directions Circulation, October 15, 1996; 94(8): 1996 - 2012. [Abstract] [Full Text]

				T. Satoh and D. P. Zipes Rapid Rates During Bradycardia Prolong Ventricular Refractoriness and Facilitate Ventricular Tachycardia Induction With Cesium in Dogs Circulation, July 15, 1996; 94(2): 217 - 227. [Abstract] [Full Text]