Giant negative T waves in Guillain-Barré syndrome.

A Guillain-Barré syndrome patient showed giant negative T waves on electrocardiography at the height of the disease, with large left ventricular hypokinesis on echocardiography and extensive defects on 123I-meta-iodobenzylguanidine myocardial scintigraphy. Gamma-globulin improved the neurological symptoms, and the above abnormalities resolved. We speculate that cardiac sympathetic nerve endings were transiently damaged, with consequent myocardial injury, due to norepinephrine toxicity.