Cocaine-related myocardial infarction: concomitant heroin use can cloud the picture.

Cocaine-related myocardial infarction is a well-known phenomenon. Concurrent heroin use can mask signs and symptoms of myocardial infarction. We discuss an unusual presentation of myocardial infarction, associated with both cocaine and heroin ("speedball") self-injection, that initially went undiagnosed.