Estimation of the systolic pulmonary arterial pressure using contrast-enhanced continuous-wave Doppler in patients with trivial tricuspid regurgitation

Noninvasive estimation of pulmonary arterial pressure is important for hemo dynamic monitoring of patients with heart disease. In patients with tricusp id regurgitation (TR), the peak velocity of TR on continuous-wave (CW) Dopp ler can be used to estimate the systolic pulmonary arterial pressure (PAPs) using the simplified Bernoulli equation. We evaluated a new technique of c ontrast-enhanced CW Doppler for calculating PAPs in patients with trivial T R. Forty-one patients without visible TR detected by color Doppler, pulsed Dop pler or CW Doppler were evaluated. Age ranged from 19 to 73 (55 +/- 12) yea rs old. Tricuspid flow signals were recorded on CW Doppler after intravenou s administration of indocyanin green (ICG) or Albunex. PAPs was calculated as; PAPs = 4 x V-TR(2) + 10 mmHg, where VTR is the peak velocity of TR. PAP s calculated using contrast-enhanced CW Doppler was compared with PAPs meas ured by the following cardiac catheterization. 1) TR signals were recorded using the contrast-enhanced CW Doppler techniqu e in 39 of 41 patients (95%) after intravenous administration of contrast a gents. 2) The error of estimate of PAPs using the contrast-enhanced CW Dopp ler technique was - 2.4 +/- 7.5 mmHg, and the percent error was -10.7 +/- 3 2.4% in all patients. In 20 of 39 patients (51%), the error of estimate was within + 5 mmHg. 3) PAPs was overestimated by 12.2 +/- 6.1 mmHg in patient s with good contrast enhancement of TR signals. The contrast-enhanced CW Doppler technique is useful for estimating PAPs no ninvasively in patients with trivial TR. It is better to assume the right a trial pressure as 3-5 mmHg, not 10 mmHg, in patients with good enhancement of trivial TR. Physiological TR may be enhanced by contrast agents in these patients.