autopsy showed that Tim Russert had an enlarged heart, NBC reported

Russert had been recording voiceovers for this Sunday's "Meet The Press" when he was stricken, NBC said. Russert's internist, Michael A. Newman, said cholesterol plaque had ruptured in an artery, causing sudden coronary thrombosis. Resuscitation was begun immediately and continued at Sibley Memorial Hospital, to no avail.

Newman said an autopsy showed that Russert had an enlarged heart, NBC reported. Russert had been diagnosed with asymptomatic coronary artery disease, which he was controlling with medication and exercise, the doctor said.