Natural History of the Idiopathic Cardiomyopathy

Natural history of the idiopathic cardiomyopathy was studied. In part I idiopathic cardiomyopathy, excluding hypertrophic obstructive cardiomyopathy, familial cardiomyopathy, endocardial fibroelastosis seen in infant and secondary cardiomyopathy, was sub-jected. Subjects reported in Part I were classified into type I with 3 subdivisions and type II by histological findings of the heart and incidence and natural history of each type were discussed with comparing each other. Natural history is variable and different in each type such as fluminating and chronic. Calculated survival rate at 5th year was 75%. In part II familial cardiomyopathy was sub-jected. In this group onset of initial symptoms was most frequent at 2nd decade that was earlier than the other non-familial group reported in part I. Age of death was variable in each case. In part III endocardial fibroelastosis seen in infant obtained from the Annual of the Pathological Autopsy Cases in Japan was subjected. Majority of this group died within one year. 76% of the cases died within 6 months were accompanied by another heart anomalies but in the survived cases over 6 months or more complication of another heart anomaly was rather rare. Major causes of death through each type of cardiomyopathy reported in part I and II were sudden death and intractable chronic congestive heart failure. In familial cardiomyopathy sudden death had occured at the rate of 75% that was much more frequent than the rate of 40% observed in the non-familial idiopathic cardiomyopathy reported in part I.