Heart arrest during dipyridamole scintigraphy: report of 3 cases

Potentially life threatening rythm disturbances, such as third degree A-V block and sinus arrest without "escape rythm", represent infrequent and unexpected events during dipyridamole thallium scintigraphy. We report three cases of cardiac arrest requiring resuscitation maneuvers after dipyridamole infusion during myocardial thallium scan. On the basis of these clinical observations we suggest that a trained cardiologist and resuscitation kit should be available in nuclear lab. Moreover elderly patients may require careful screening for preexisting conduction defects and sick sinus syndrome. When dipyridamole infusion provokes severe bradyarrhythmias not related to myocardial ischemia, a transesophageal electrophysiological study should always be performed.