Nonpenetrating cardiac injuries due to direct precordial blunt impacts are a 
commonly encountered phenomenon in medicolegal offices. These injuries vary from 
contusions to valvular lacerations, or papillary muscle rupture to coronary 
arterial injury with resulting infarction. A less commonly occurring 
manifestation of nonpenetrating injury is a concussion of the heart (commotio 
cordis), often with dramatic physiological consequences but no morphologic 
cardiac injury. We describe four case reports of this entity. The cases were 
collected over a 5-year period (1978-1983) from the Wayne County Medical 
Examiner's Office in Detroit, Michigan.