In vascular ultrasound, hepatic vein triphasicity describes the normal waveform pattern seen in the hepatic veins, reflecting right atrial pressure changes throughout the cardiac cycle. This characteristic flow consists of three distinct phases: an “a” wave (atrial contraction-related retrograde flow), an “s” wave (systolic forward flow), and a “d” wave (diastolic forward flow). Loss of this triphasic pattern, often becoming biphasic or monophasic, can indicate various underlying cardiac or liver pathologies.
Understanding hepatic vein triphasicity is crucial for diagnostic ultrasound. Changes in this waveform can be early indicators of conditions like right-sided heart failure, tricuspid regurgitation, or hepatic venous outflow obstruction. Sonographers use this assessment to evaluate liver hemodynamics and cardiac function, making it a key parameter in comprehensive medical and vascular ultrasound examinations.
