Low voltage ECG in myocarditis: peripheral edema as a plausible contributing mechanism.

A 24-year-old woman was hospitalized with acute myocarditis that led to multiple organ, including heart, failure, with fluid retention. An echocardiogram showed left ventricular ejection fraction approximately 10%, and her electrocardiogram (ECG) revealed low voltage. She rapidly recovered and was discharged 15 days after admission. On evaluation at 1, 10, and 22 weeks after discharge, she was asymptomatic, with unlimited exercise tolerance. An echocardiogram 11 weeks after discharge from the hospital showed left ventricular ejection fraction of approximately 60%. Correlations of weights with ECG QRS voltage parameters in the hospital revealed r = 0.80 and 0.83, with P = 0.021 and 0.029, suggesting that >or=64% of the attenuation of the QRS potentials could be accounted for by the corresponding gain in weight.