Bradyarrhythmias incident to thrombolysis for acute inferior wall infarction. A caveat.

Of ten consecutive patients (eight men, two women; mean age, 59 years) seen over a ten-month period with acute inferoposterior infarction treated with thrombolytic therapy, seven patients demonstrated significant rhythm disturbances at a time interval consistent with clot lysis and in a setting of other clinical markers predictive of reperfusion. One patient had a ventricular arrhythmia treated with intravenous procainamide, but six patients had marked bradyarrhythmias (sinus bradycardia, four patients; and 2 degrees atrioventricular block, one patient) associated with hemodynamic compromise. Urgent treatment consisting of intravenous atropine sulfate (1 mg) briskly restored sinus rhythm and normal arterial pressure within 1 min. Bradyarrhythmias incident to thrombolysis for acute inferoposterior infarction appear to arise as a vagally mediated cardiovascular reflex (Bezold-Jarisch) and the rapid vagolytic effect of intravenous atropine sulfate makes this therapy specific and appropriate.