to study the effects of digitalis on the sinus node and the mechanisms involved , 16 patients with the sick sinus syndrome had electrophysiologic assessment of sinus nodal function during ( 1 ) control study , ( 2 ) after pharmacologic autonomic blockade with propranolol ( 0.2 mg/kg body weight and atropine sulfate 0.04 mg/kg intravenously ) , and ( 3 ) 10 minutes after 0.01 mg/kg of intravenous ouabain .
C0037052
sick sinus syndrome
C0033497
propranolol