Value of the tricuspid valve echogram for estimating right ventricular end-diastolic pressure during vasodilator therapy

Abstract

To evaluate the potential usefulness of the tricuspid valve echogram for assessing right ventricular end-diastolic pressure, 9 patients with right heart failure and 10 normal subjects were studied. In the nine patients, the initial P-R interval of 184 ± 26 (±1 standard deviation) ms did not differ significantly from the normal subjects' value of 170 ± 17 ms; however, the A-C Interval of 162 ± 23 ms was significantly longer (p < 0.001) and the PR-AC interval of 21 ± 16 ms was shorter (p < 0.001) when compared with corresponding control measurements. Nitroprusside infusion significantly decreased the right ventricular end-diastolic pressure from 15 ± 4 to 8 ± 4 mm Hg in the nine patients (p < 0.001). Additionally, it decreased the average A-C interval to 137 ± 25 ms (p < 0.001) and the mean PR-AC interval to 46 ± 18 ms (p < 0.05). However, the PR-AC interval did not correlate closely with the right ventricular end-diastolic pressure. Furthermore, it did not separate elevated right ventricular end-diastolic pressures from normal pressures. However, a qualitative assessment of the morphologic appearance of tricuspid valve closure motion during the A-C segment was predictive of right ventricular enddiastolic pressure over the wide range produced by nitroprusside infusion. In addition, it reliably identified patients with elevated end-diastolic pressures. All nine patients had a B plateau or hump in the initial resting tricuspid valve echogram when the right ventricular end-diastolic pressure was 9 mm Hg or greater. Therefore, an analysis of morphologic changes in the tricuspid valve closure motion provides a valuable noninvasive tool for assessing right ventricular end-diastolic pressure at rest and during acute vasodilator therapy in patients with right heart failure.