RESTRICTIVE CARDIOMYOPATHIES IN CHILDHOOD - ETIOLOGIES AND NATURAL-HISTORY

Restrictive cardiomyopathy is rare in childhood and little is known ab out the causes and outcome. This lack of information results in extrap olation of adult data to the care and management of children, who migh t require different treatment from that of adults. This study was unde rtaken retrospectively to evaluate the causes and natural history of r estrictive cardiomyopathy in childhood. Twelve cases of restrictive ca rdiomyopathy were identified by database review of patient records fro m 1967 to 1994. The cases were selected on the basis of echocardiograp hic and cardiac catheterization criteria. Charts were reviewed for the following variables: age, sex, cause, right- and left-sided hemodynam ics, pulmonary vascular resistance index, shortening fraction, therapy , and outcome. There were 6 males and 6 females with a mean age of 4.6 years at presentation (median, 3.4 yr,. range, 0.9 to 12.3 yr). Etiol ogies included hypertrophic cardiomyopathy in 3 patients, cardiac hype rtrophy with restrictive physiology in 3, idiopathic in 2, familial in 2 (twins), ''chronic eosinophilia'' in 1, and ''post inflammatory'' w ith no definitive causes in 7. At presentation the mean shortening fra ction was 33% +/- 2% (mean +/- SEM), average right Ventricular pressur es were 44/13 +/- 3/1, average left ventricular pressures were 88/25 /- 4/3, and the mean pulmonary vascular resistance index was 3.4 +/- 1 .3 U . m(2) (n=9), but increased to 9.9 +/- 3.1 U . m(2) (n=5, p=0.04) by 1 to 4 years after diagnosis. Four of the 12 patients had embolic events (1, recurrent pulmonary emboli; I, saddle femoral embolus; 2, c erebrovascular accidents) and 9 of 12 died within 6.3 years despite me dical therapies, which included diuretics, verapamil, propranolol, dig oxin, and captopril. In conclusion, restrictive cardiomyopathy in chil dhood is commonly idiopathic or associated with cardiac hypertrophy, a nd the prognosis is poor. Embolic events occurred in 33% of our patien ts, and 9 of 12 patients died within 6.3 years. Within I to 4 years of diagnosis, patients may develop a markedly elevated pulmonary vascula r resistance index; therefore, transplantation should be considered ea rly.