Thunderclap headache as the presenting symptom of myocardial infarction.

Headache as the presenting symptom of myocardial ischemia has been reported in more than 20 cases. These headaches have been described as of gradual onset, associated with exertion and with EKG changes. We present herein the first case of thunderclap headache occurring at rest as the sole symptom of an acute myocardial infarction.