Usefulness of delayed enhancement magnetic resonance imaging for detecting cardiac rupture caused by small myocardial infarction in a case of cardiac tamponade.

Delayed enhancement magnetic resonance imaging (DE-MRI) has excellent spatial resolution and compared with other cardiac imaging techniques it can detect a small myocardial infarction (MI) or a subendocardial infarction. A 76-year-old man was admitted for loss of consciousness because of cardiac tamponade. The cause of tamponade was unknown, but electrocardiography and blood test suggested a recent MI. The removal of 100 ml bloody fluid by immediate pericardiocentesis normalized his hemodynamics, and he regained consciousness. Neither echocardiography nor scintigraphy could determine the location of the MI or rupture, but DE-MRI clearly demonstrated a transmural enhancement in a very narrow range of the lateral wall of the left ventricle. Coronary angiography revealed a severely stenotic lesion in the obtuse marginal branch of the left circumflex artery. DE-MRI is a powerful tool for diagnosing small MI that are undetectable with other imaging. Therefore, DE-MRI should be applied in cases with cardiac tamponade by unknown causes.