Reversible asymmetric septal hypertrophy in acute myocarditis. Serial findings of two-dimensional echocardiogram and thallium-201 scintigram.

Serial two-dimensional echocardiographic and thallium-201 scintigraphic findings are described in a patient with acute myocarditis diagnosed by endomyocardial biopsy. On the 4th day of illness, just before the onset of congestive heart failure, the echocardiogram showed asymmetric septal hypertrophy (IVS/PW = 16 mm/10 mm = 1.6) and thallium-201 scintigram showed the ventricular septal thickening. On the 8th day of illness, when severe congestive heart failure was seen, asymmetric septal hypertrophy disappeared (IVS/PW = 8 mm/8 mm = 1.0), the left ventricle dilated markedly (LVDd = 63 mm), and the wall motion became poor (EF = 0.24). After one month, when congestive heart failure and clinical inflammatory findings disappeared, the contractility somewhat improved (EF = 0.43), although marked left ventricular dilatation remained. Thallium-201 scintigram showed some scattered persistent perfusion defects, thinning of the ventricular septal thickening, and dilatation of the left ventricle. The right ventricular endomyocardial biopsy revealed the histologic findings of the late stage of acute myocarditis. It is concluded that transient thickening of the ventricular wall may represent early changes in acute myocarditis.