AMINOPHYLLINE INDUCED ATRIAL-FIBRILLATION

Atrial fibrillation (AF) with a rapid ventricular response was induced by intravenous (IV) aminophylline during treatment for symptomatic pu lmonary disease in three patients who had no evidence of underlying he art disease or previous cardiac arrhythmia. Serum theophylline concent ration was therapeutic in two patients and toxic in the third. Previou s reports of AF related to aminophylline have underscored its associat ion with toxic serum theophylline concentration. Conversion to sinus r hythm occurred at a time interval (9-14 hours) appropriate to the seru m decay of aminophylline, after its cessation. A shortened atrial refr actory period and dispersed recovery of excitability consequent to ami nophylline may engender multiple reentrant circuits and lead to AF. IV diltiazem was more effective than digoxin in the ventricular rate con trol of AF prior to conversion to sinus rhythm.