Severe electrocardiographic abnormalities during arfonad administration.

Severe and reversible electrocardiographic abnormalities (first degree atrioventricular block, left bundle branch block, ventricular fibrillation), were induced by the administration of Arfonad in a patient with type III acute aortic dissection previously chronically treated with alpha-methyl-dopa. Any other possible cause of the electrocardiographic changes was excluded on the basis of clinical findings and laboratory studies. The explanation of the electrocardiographic abnormalities induced by Arfonad are not readily apparent, also on careful review of the literature. We suggest a strict electrocardiographic monitoring during Arfonad administration especially in patients with cardiac conduction defects and previous administration of cardiac cathecholamines depleting drugs.