Primary cardiomyopathy in identical twins

Seventeen year old identical twin brothers with no family history of cardiopathy began experiencing palpitations almost simultaneously. In both, examination revealed marked cardiomegaly and hypokinesia of the ventricular walls, and clinical and radiologic signs of progressive cardiac failure developed a few days later. Both boys died suddenly, 49 days and 5 months, respectively, after the initial examination. Electrocardiographic and vectorcardiographic studies revealed a severe intraventricular conduction disturbance that coincided with histologic changes in the myocardial tissue, including profuse interstitial fibrosis, hypertrophy and degeneration of the myocardial fibers, aberrant arrangement of the muscular fibers and considerable alteration of the structure of cardiac tissue. In the absence of hereditary and chromosomal factors, and excluding possible viral intervention during fetal life, it is believed that a teratogenic factor can produce the structural alterations of the tissue and derangement of the fibers observed in these hearts. The irregular contractions of the heart at the level of the net-like meshwork, disarrangement of myocardial fibers, and adaptative mechanisms of the heart inherent in the destruction of the contractile tissue contributed to the functional cardiac disorders that resulted in congestive heart failure and sudden death in these twins.