Delayed diagnosis and management of an "occult" stab wound to the heart.

Stab wounds to the heart can present without clinical evidence of injury. Echocardiography has been advocated as an alternative to subxyphoid exploration in these cases. We present a case in which two serial echocardiography exams missed a diagnosis. Electrocardiographic changes and elevation of serial troponin I levels suggested the diagnosis, which was confirmed by thoracoscopy. Repair was facilitated by use of adenosine cardiac standstill.