2001 Volume 65 Issue 10 Pages 863-866
The present study was designed to determine whether the wall thickening seen in acute myocarditis is caused by interstitial edema. The study group comprised 25 patients (idiopathic myocarditis, 17; eosinophilic myocarditis, 8) in whom acute myocarditis was diagnosed histologically and who underwent echocardiography and endomyocardial biopsy during both the acute and convalescent phases. The following echocardiographic parameters were measured: interventricular septum and left ventricular posterior wall thickness, left ventricular end-diastolic dimension, and left ventricular ejection fraction. Based on the myocardial biopsy specimens, the degree of interstitial edema was classified into 3 grades [(-), 1(+), 2(+)] and the transverse diameter of cardiac myocytes was measured using light microscopy. The thickness of both the interventricular septum and left ventricular wall decreased from 14.3±3.7 mm and 13.3±2.4 mm in the acute phase to 9.7±1.7 mm (p<0.001) and 10.2±1.7 mm (p<0.0001), respectively, in the convalescent phase. Edema was present in 22 patients (88.0%) in the acute phase, but in the convalescent phase, edema was present in only 7 patients (28.0%), indicating a significant reduction in the degree of edema (p<0.0001). Cardiac myocyte diameter did not differ significantly between the acute (13.6±1.1 μm) and convalescent (13.8±1.8 μm) phases. (Jpn Circ J 2001; 65: 863 - 866)
