the latter was blocked by intravenous administration of propranolol and phenoxybenzamine.these responses were related primarily to conversion of ventricular fibrillation rather than to the electrical discharge of countershock because countershock without ventricular fibrillation caused more transient and smaller responses than those observed with defibrillation : furthermore , the hemodynamic effects of defibrillation were augmented by prolongation of the duration of fibrillation .
C0033497
propranolol
C0042510
ventricular fibrillation