Bucindolol, a beta blocker, decreased ventricular fibrillation and maintained mechanical function in a pig model of acute myocardial ischemia.
Bucindolol is a new beta blocker with marked vasodilatory properties and intrinsic sympathomimetic activity. We tested its potential effect against ventricular fibrillation (VF), in a pig model of acute myocardial ischemia. Bucindolol 6 mg/kg IV was administered in two equally divided doses, the first 30 minutes prior to, and the second 10 minutes after, ligation of the anterior descending coronary artery (CAL) in anesthetized open-chest pigs. Bucindolol decreased the incidence of VF to 1/11 versus 14/16 in the control group (p less than 0.005). Bucindolol also decreased the duration of ventricular tachycardia, 15 +/- 8 seconds versus 104 +/- 32 seconds in the control group (p less than 0.01). Bucindolol maintained LVmaxdP/dt at predrug and pre-CAL values, whereas LVmaxdP/dt was decreased by CAL in the control group. Bucindolol decreased arterial pressure and heart rate. Bucindolol increased blood flow in the peripheral ischemic zone (24.6 +/- 1.8% versus 16.2 +/- 1.7% (percent of pre-CAL value) in controls, p less than 0.002), as well as in the nonischemic zones (periischemic zone: 126.4 +/- 6.1% versus 96.7 +/- 4.8% in the control group, p less than 0.0005; remote nonischemic zone: 126.6 +/- 7.1% versus 87.1 +/- 4.3% of pre-CAL value in the control group, p less than 0.0001). Bucindolol had marked antiarrhythmic effects that were associated with beneficial effects on the mechanical function of the left ventricle and on blood flow to the ischemic myocardium.
Department of Medicine, Groote Schuur Hospital, South Africa.
C A
CA
Muller
L H
LH
Opie
C A
CA
Pineda
M
M
Peisach
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D003327:Coronary Disease / Q000188:drug therapy* / Q000503:physiopathology; D004195:Disease Models, Animal; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D008297:Male; D011412:Propanolamines / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D013552:Swine; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000187:drug effects
D000319:Adrenergic beta-Antagonists; D011412:Propanolamines; C024307:bucindolol