Tricuspid regurgitation is leak in the valve between right ventricle and right atrium. Right atrium is the upper chamber from which right ventricle, the lower chamber receives blood when it relaxes after a contraction. Tricuspid valve normally prevents backflow of blood into the right atrium when the right ventricle contracts and pumps blood to the lungs for oxygenation.
Trivial to mild leak in the tricuspid valve is common in normal individuals and can be detected by sensitive tests like colour Doppler echocardiogram, ultrasound study of the heart. This video clip is an illustration of mild tricuspid regurgitation on colour Doppler echocardiogram. A bluish mosaic jet can be seen going away from right ventricle, into the right atrium when it is contracting. This is mild tricuspid regurgitation. The image appears upside down because the echo beam is looking at the heart from the lower part.
Mild leak in the tricuspid valve is not of much significance. If the leak occurs as a result of increased pressure in the right ventricle, the cause of increase in pressure has to be checked. It could be an obstruction to the outflow of the right ventricle or increase in pressure in the blood vessels of the lungs. Both of these are significant conditions which need treatment.
Presence of mild leak helps the echocardiographer to assess the pressure in the right ventricle. Pressure in the right ventricle can be estimated from the velocity of the tricuspid regurgitation jet. This picture illustrates the measurement of TR jet velocity and gradient by a test known as Doppler echocardiography.
TR gradient is the pressure difference between the right ventricle and right atrium when the right ventricle contracts. Usually a nominal value of 10 mm Hg representing the pressure in the right atrium is added to the TR jet velocity gradient to get the estimated right ventricular systolic pressure or RVSP. It is the maximum pressure developed when the right ventricle contracts.