A chest radiograph showed an enlarged heart with mild pulmonary venous congestion, and the electrocardiogram sinus rhythm with non-specific ST segment changes. The patient was given symptomatic treatment to correct the acidosis and hyperkalaemia. Dopamine (up to a dose of 10 ,ug/kg/min) was given intravenously, which resulted in an increase in pulse rate to 120/min but a fall in blood pressure to 70/40 mm Hg. In view of the known alcohol abuse 100 mg thiamine was injected intravenously. A few hours later his blood pressure had risen to 95/40 mm Hg, and a high cardiac output state developed with bounding pulses and pistol shot sounds as well as Duroziez's sign over the femoral arteries. The cyanosis disappeared. At cardiac catheterisation using a SwanGanz thermodilution catheter the high cardiac output was confirmed and the peripheral vascular resistance was found to be low (Table). The patient was treated with thiamine and a sodium restricted diet. The cardiac output and peripheral resistance gradually returned to normal values, but right atrial and pulmonary wedge pressures were still raised on the third day (Table) when the Swan-Ganz catheter had to be removed because of a temperature rise to 39°C.Within a week of admission the electrocardiogram and renal and liver function tests returned to normal.The chest radiograph showed no pulmonary congestion after two weeks, and the heart size returned to normal a few weeks later. Erythrocyte transketolase activity before treatment was 43 U/mmol (normal 8-8-12 5 U/mmol) of haemoglobin and the thiamine pyrophosphate effect was 22% (normal 5-25%). On retesting four weeks later the transketolase activity was 9.8 U/mmol of haemoglobin and the thiamine pyrophosphate effect 3%.