We have studied the changes of cardiac troponin I(cTnI) level and left ventricular ejection fraction(LVEF) before and after treatment of IVGG to evaluate the efficacy of single high dose of intravenous gammaglobulin(IVGG)(2.0gm/kg) therapy for improving cardiac function and clinical symptoms and signs in patients with clinically suspected acute myocarditis.

The patients consisted of 18 cases who admitted increased cTnI with clinically suspected acute myocarditis caused by viral infection, Kawasaki disease and fever unknown origin(FUO) from Jan. 1995 to Jun. 1998. The control group consisted of 20 cases suffered from hand-foot-mouth disease, herpangina and high fever with rash. The level of cTnI was measured by Chemiluminiscent immunoassay method(normal<0.1 ng/ml) and cardiac function was evaluated by left ventricular ejection fraction(LVEF)(normal 64~83%) by echocardiogram.

The level of cTnI increased to 0.306±0.209ng/m1 and LVEF decreased to 60.1±1.6% before treatment of IVGG significantly as compared with control group(p<0.05). All cases were returned to normal range of LVEF(71.4±3.7%) and decreased cTnI significantly(0.089±0.082ng/m1) after treated with IVGG within 1 week in patients group(p<0.05).

The single high dose of IVGG(2.0gm/kg) therapy was rapid and effective improvement of cardiac function and clinical symptoms and signs of acute myocarditis, and the measurement of serum cTnI and LVEF may help to diagnose and evaluate efficacy of IVGG on it.