Detection of tricuspid regurgitation by contrast echocardiography

Contrast echocardiography with simultaneous M-mode echocardiography was performed in 77 cases of tricuspid regurgitation (TR) and 168 cases having no TR (non-TR). The echocardiographical characteristics of TR were as follows: 1) By the subxiphoid approach, a contrast appeared in the inferior vena cava during systole. In some cases of non-TR, a similar appearance was noted but limited to the atriosystolic or late systolic-to-early diastolic phases. Such confusing cases should be excluded by the simultaneous observation of the M-mode contrast echogram. 2) By apical four-chamber view, a negative contrast echo above the tricuspid valve and subsequent back and forth movements of the contrast across the valve were useful. This movement, however, may be misleading on two-dimensional echo and the M-mode echocardiogram was also necessary to obtain the exact timing and the direction of regurgitant flow. 3) Presence of the dilated inferior vena cava. The sensitivity of this method was extremely high, and the specificity was also excellent for TR.