A 33-year-old male with hepatitis C.Spectral analysis of the main hepatic vein (MHV) demonstrates normal triphasic waveforms. The “a” wave corresponds to the atrial contraction, which occurs at the end diastole followed by the “S” wave caused by the motion of the atrioventricular septum during midsystole. The “v” wave corresponds to the opening of the tricuspid valve followed by the “D” wave of the early diastolic right ventricular filling.