Cardiac tamponade: a new complication in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes.

We report the first case of cardiac tamponade in a 14-year-old female patient with an underlying illness of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). The patient underwent a subxiphoid pericardiocentesis and pericardiotomy smoothly and was discharged with no sequelae. The coexistence of massive pericardial effusion and MELAS has never been mentioned in any literature. This case report attempts to exemplify the possibility of this connection.