Tricuspid regurgitation (TR) is a common finding that can be detected with use of Doppler echocardiographic technique in patients with right ventricular dysfunction as well as in normal children, adolescents and adult. It is difficult to evaluate the right ventricular function by conventional method, including echocardiography, especially in case with TR.

To determine the degree and relationship of right ventricular function and duration of TR, we examined the 41 patients with TR associated with heart disease, group 2 (n=19) with no definitive evidence of right ventricular dysfunction nor significant pulmonary hypertension, and group 3 (n=22) with right ventricular dilatation or wall motion abnormality, or history of longstanding pulmonary hypertension or moderate or severe TR, and compared 59 normal subjects (group 1) with trivial or mild TR without definitive heart disease. Using Doppler echocardiography, duration of TR (TRD) and pulmonary ejection period (ET) is measured, and calculated the TR time interval (RTI) by the difference of TRD and ET divided by ET.

Pre-ejection period (PEP), ET and systolic time interval (STI, PEP/ET) of right ventricle are significantly prolonged in group 2 and 3 compare to those of group 1 (p<0.001 respectively), TRD is significantly prolonged in group 3 compare to those of group 1 and 2, and isovolumic contraction time (IRT), isovolumic relaxation time (IRT) and RTI are significantly different in each group and prolonged in group 2 and 3. RTI is significantly correlated to STI (r=0.56), ICT (r=0.75) and IRT (r=0.94), but independent to heart rate.

We conclude that Doppler measurement of RTI (TRD-ET)/ET{=(ICT+IRT)/ET} is a simple and useful new index for the evaluation of RV function including systolic and diastolic function.