Fatal cytomegalovirus myocarditis in a seronegative ALL patient

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.