[The estimation of the severity of tricuspid insufficiency by Doppler color: the effects of gain, pulse repetition frequency and the echographic view].

INTRODUCTION AND OBJECTIVES

Regurgitant jet area is to date the most widely accepted color Doppler parameter for quantitation of atrium-ventricular regurgitations. In experimental studies, it has been demonstrated that color regurgitant jet area is greatly influenced by technical settings. The present study was aimed to analyze the effect of gain setting, pulse repetition frequency and echocardiographic plane on color jet area in patients with tricuspid regurgitation.

METHODS

We studied 64 patients with nontrivial (more than 1 cm2), rheumatic tricuspid regurgitation. Examinations were performed in apical four-chamber and right ventricle inflow-tract views, at two gain settings (subsaturation gain and 1/3 reduced gain) and at two pulse repetition frequencies (3.1 and 3.8 kHz). Therefore, every regurgitant jet was study under 8 different technical conditions. The remaining technical settings were held unchanged included throughout the studies. The traced area induced central varianced and aliased signals, as well as the immediately contiguous nonturbulent velocities that were moving in the same direction as the jet. Measurements were taken from 5 and 3 representative cycles in patients with atrial fibrillation and sinus rythm, respectively.

RESULTS

Globally, reduction in gain setting produced a color area decrease by 50%. This reduction was of greater extent for small jets (less than 5 cm2, 45 +/- 17%) with respect to larger jets (more than 5 cm2, 61 +/- 30%, p = 0.0009). Results were similar for both apical four-chamber and right ventricle inflow views and for the two pulse repetition frequencies. At a given color gain level and echocardiographic view, pulse repetition frequency at 3.1 kHz produced greater color areas (by 3-11%) than frequency at 3.8 kHz, but the difference was not significant. Overall, color jet area was significantly greater in right ventricle inflow view than in apical four-chamber view, but substantial individual variability was observed. Difference between both views was greater than 40% in 28% of patients, with the largest color area in right ventricle inflow view in most, especially in those patients with eccentric jets.

CONCLUSIONS

Gain setting and echocardiographic view greatly affect regurgitant jet area by color Doppler in patients with tricuspid regurgitation. Therefore, standardization of technical settings is mandatory in order to avoid diagnostic pitfalls.