Safety and utility of endomyocardial biopsy in infants, children and adolescents: a review of 66 procedures in 53 patients.

The benefits and risks of endomyocardial biopsy in infants, children and adolescents were determined by reviewing the indications for and complications and results of 66 procedures in 53 patients aged 2 months to 20 years. One patient had a pneumothorax, and three had a right ventricular perforation. Ventricular tachycardia developed in four patients; it was treated with lidocaine in three and was self-limited in one. The procedure was unsuccessful in two patients. Among 25 patients with a prebiopsy diagnosis of idiopathic dilated cardiomyopathy, microscopic features were consistent with cardiomyopathy in 24 (96%) and were normal in 1. Of nine patients with clinically suspected myocarditis, only two (22%) had microscopic evidence of inflammation, and seven had chronic nonspecific features suggestive of dilated cardiomyopathy. Of eight patients with unexplained arrhythmias, six (75%) had microscopic findings compatible with dilated cardiomyopathy and two had myocarditis. Biopsy tissue samples from seven patients with nondilated forms of cardiomyopathy (four hypertrophic, three restrictive) were consistent with the clinical diagnosis in six and were inadequate in one. Cardiac biopsies were also performed in four patients with other disorders. Among the 51 patients with adequate biopsy specimens, microscopic features were considered diagnostic in 5, confirmatory in 44 and not helpful in 2 with normal tissue. The results indicate that endomyocardial biopsy is safe in infants, children and adolescents. It is useful for the evaluation of cardiomyopathy and specific secondary forms of myocardial disease. There seems to be little correlation, however, between clinical and tissue diagnoses of myocarditis.