Myocarditis and cardiomyopathy: diagnosis by endomyocardial biopsy

To investigate the incidence of myocarditis, 30 patients, with unexplained congestive heart failure, underwent endomyocardial biopsy. For each case three to five samples were examined on light and electron microscopy. Inflammatory infiltrates and injury to adjacent myocytes consistent with myocarditis were detected in 3 of the 30 cases (10%). Changes attributable to cardiomyopathy were found in the remaining 27 cases. Two of the three patients with biopsy-proven myocarditis were treated with prednisone and azathioprine. Their control biopsies six months later showed interstitial fibrosis and absence of inflammatory infiltrates. They clinically improved but hemodynamic and angiocardiographic patterns failed to show the expected improvement. The third patient affected by myocarditis died two weeks later.

in our series of patients with unexplained congestive heart failure, the incidence of biopsy-proven myocarditis resulted low (10%). The results of the immunosuppressive treatment in two patients with myocarditis were unconclusive. Therefore the effectiveness of such therapy should be confirmed in a larger number of patients.