Perimyocarditis. Report on an unusual cause.

A 29-year-old man had a febrile illness accompanied by chest pain and tachycardia. The ECG suggested either myocarditis or acute ischemia. Heart muscle enzymes were normal, the peripheral blood count showed absolute and relative lymphocytosis, and an echocardiogram disclosed a small pericardial effusion. After defervescence, splenomegaly was noted and the SGPT level was elevated to four times normal. There was a greater than fourfold rise in titer of IgM antibodies to cytomegalovirus. This is only the second report in detail of perimyocarditis caused by cytomegalovirus mononucleosis. An interesting aspect of the case was an afebrile prodrome that lasted for more than one week, during which prostration, palpitations, and breathlessness on exertion were present and the sole physical finding was tachycardia.