Echocardiogram in tricuspid regurgitation

Echocardiogram in tricuspid regurgitation

Echocardiogram in tricuspid regurgitation: TR Colour Jet
Echocardiogram in tricuspid regurgitation: TR Colour Jet

Colour Doppler echocardiogram in a slightly tilted apical four chamber view showing tricuspid regurgitation jet. Right ventricle is seen dilated and hypertrophied, with a prominent moderator band, seen just below the RV label. Right atrium is also dilated, both due to severe pulmonary hypertension.

The right ventricular pressure is estimated by adding the expected right atrial pressure from the observed jugular venous pressure to the peak TR gradient.

The TR gradient is calculated from the TR velocity using the Bernoulli’s Equation:

P = 4 V2

P = pressure gradient, V = velocity of the TR jet.

Proper alignment of the jet to the axis of Doppler imaging line is also important in getting an accurate estimate of the gradient. An improperly aligned jet will lead to underestimation of the gradient and hence the level of pulmonary hypertension. We have to image in multiple views to get the maximum jet velocity. While estimating the right ventricular pressure, usually the right atrial pressure is taken as 10 mm Hg and added to the TR gradient to get the estimated right ventricular systolic pressure.

Right ventricular systolic pressure will be equal to the pulmonary artery systolic pressure in the absence of pulmonary stenosis. In cases with right heart failure, the calculation will underestimate the right ventricular systolic pressure unless you take into account the elevated right atrial pressure. Right atrial pressure can be assessed clinically from the jugular venous pressure.

An indication of high right atrial pressure can be obtained on echocardiography by assessing the inferior vena caval diameter and its respiratory change in dimension. Absence of inspiratory collapse of the inferior vena cava, known as IVC plethora, indicates high right atrial pressure, in which case a higher value than 10 mm Hg has to be added to get the estimated right ventricular systolic pressure (RVSP).