to study the diagnostic possibility and the mechanisms involved in sinus node dysfunction , 23 patients with sick sinus syndrome were evaluated by the basic electrophysiological method ( recovery times , secondary postpacing phases , sinoatrial conduction times ) before and after pharmacologic autonomic blockade with i.v . propranolol 0.2 mg/kg and atropine 0.04 mg/kg , and by continuous rhythm monitoring .
C0037052
sick sinus syndrome
C0033497
propranolol