A 35-year-old man with no history of cardiovascular disease presented with severe biventricular heart failure, after a 6-week history of fever, rigor, weight loss and unresolving gingivitis. An electrocardiogram showed sinus tachycardia with T-wave flattening, and chest x ray examination confirmed congestive heart failure and cardiomegaly. Serum troponin I was raised at 20.1 μg/l, and …