Assessment of aortic regurgitation by transesophageal color Doppler imaging of the vena contracta: Validation against an intraoperative aortic flow probe

OBJECTIVES This study was performed to validate the accuracy of color flow vena contracta (VC) measurements of aortic regurgitation (AR) severity by c omparing them to simultaneous intraoperative flow probe measurements of reg urgitant fraction (RgF) and regurgitant volume (RgV). BACKGROUND Color Doppler imaging of the vena contracta has emerged as a sim ple and reliable measure of the severity of valvular regurgitation. This st udy evaluated the accuracy of VC imaging of AR by transesophageal echocardi ography (TEE). METHODS A transit-time how probe was placed on the ascending aorta during c ardiac sugery in 24 patients with AR. The flow probe was used to measure Rg F and RgV simultaneously during VC imaging by TEE. mow probe and VC imaging were interpreted separately and in blinded fashion. RESULTS A good correlation was found between VC width and RgF (r = 0.85) an d RgV (r = 0.79). All six patients with VC width >6 mm had a RgF >0.50. All 18 patients with VC width <5 mm had a RgF <0.50. Vena contracta area also correlated well with both RgF (r = 0.81) and RgV (r = 0.84). All six patien ts with VC area >7.5 mm(2) had a RgF >0.50, and all 18 patients with a VC a rea <7.5 mm(2) had a RgF <0.50. In a subset of nine patients who underwent afterload manipulation to increase diastolic blood pressure, RgV increased significantly (34 +/- 26 mi to 41 +/- 27 mi, p = 0.042) while VC width rema ined unchanged (5.4 +/- 2.8 mm to 5.4 +/- 2.8 mm, p = 0.41). CONCLUSIONS Vena contracta imaging by TEE color flow mapping is an accurate marker of AR severity. Vena contracta width and VC area correlate well wit h RgF and RgV obtained by intraoperative flow probe. Vena contracta width a ppears to be less afterload-dependent than RgV. (J Am Coil Cardiol 2001;37: 1450-5) (C) 2001 by the American College of Cardiology.