[Usefulness of endomyocardial biopsy in myocarditis and dilated cardiomyopathy]

Through an endomyocardial biopsy (EB) we studied 30 patients, 15 of them with suspicious clinical diagnosis of myocarditis (M) and 15 with dilated cardiomyopathy (DC). In only 4 (26%) out of the 15 patients with M we found inflammatory changes in the biopsy. By serendipity a metastatic malignant tumor was found in one patient. In 9 (60%) out of the 15 cases with DC the histological report was compatible with interstitial fibrosis, hypertrophic myofibrils, myositic degeneration and atrophy and in 2 of these patients inflammatory cell infiltration. In all patients in whom we found these inflammatory process the illness was present for less than 6 months. We concluded that in only a limited percentage of patients with the clinical diagnosis of M inflammatory changes are present (26% in our study). In patients with DC the information given in few cases (13%) an inflammatory cell infiltration could be seen. The probability of finding inflammatory changes is higher if the duration of the disease is less than 6 months. It is important to have in mind that through this method an occult pathology could be discovered.