Location and clinical implications of high-degree atrioventricular block during dipyridamole infusion: a case report.

We describe a patient with bifascicular block, who developed transient high-degree atrioventricular block during dipyridamole infusion. This patient was subsequently found to have significant His-Purkinje disease at electrophysiology study, and underwent permanent pacemaker implantation. Spontaneous atrioventricular block was documented during follow-up. This case report raises the issue of dipyridamole safety in patients with intraventricular conduction defects, and contributes an additional mechanism to the possible explanation of dipyridamole-induced atrioventricular block.