Surviving a stressful MIBI scan

Dipyridamole/technetium sestamibi scans (more commonly known as MIBI scans, an acronym for methoxyisobutyl isonitrile) are used commonly for the diagnosis and risk stratification of coronary artery disease. Adverse events from MIBI scans are extremely rare. We present the case of a 64-year-old man who was successfully resuscitated after two asystolic episodes following dipyridamole infusion for a MIBI scan. The second asystolic episode occurred in the emergency department 40 minutes after the patient had been transferred from the Cardiac Stress Test Laboratory. To our knowledge, there are no previous reports of patients having two discrete asystolic episodes or an asystolic episode as delayed as we report after a MIBI scan. Our case illustrates why emergency physicians should be aware of the potential for asystole following MIBI scanning and why aminophylline, the antidote for dipyridamole, should be readily available in emergency departments that could see patients after pharmacologic stress testing. Patients who become asystolic following dipyridamole infusion likely require prolonged cardiac monitoring, given the potential for further episodes after periods of hemodynamic stability.