Clinical utility of new real time three-dimensional transthoracic echocardiography in assessment of mitral valve prolapse

Background: Noninvasive and accurate assessment of mitral valve anatomy has become integral in the presurgical evaluation of patients with mitral valve prolapse (MVP). Recently developed real time three-dimensional (RT3D) ultrasound allows online acquisition, rendering, and can provide accurate information on cardiac structures. We sought to evaluate the feasibility of RT3D for the assessment of MVP segments when compared with transesophageal echocardiography (TEE) and intraoperative findings. Methods: We examined 42 patients with MVP using RT3D, two-dimensional (2D) transthoracic echocardiography (TTE) and TEE. For RT3D analysis, cropping planes were used to slice the 3D volume on line to visualize the prolapsed segments of the mitral valve leaflets. The mitral valve was divided into six segments based on the American Society of Echocardiography's recommendations. Two experienced cardiologists evaluated echocardiographic images. Results: Adequate RT3D images of the mitral valve were acquired in 40 out of 42 patients. The sensitivity and specificity of RT3D for defining prolapsed segments when compared with TEE were 95% and 99%, respectively (anterior leaflet: 96% and 99%, posterior leaflets: 93% and 100%, respectively). The sensitivity and specificity of TTE were 93% and 97%, respectively (anterior leaflet: 96% and 98%, posterior leaflets: 90% and 97%, respectively). Interobserver agreement for RT3D (Kappa 0.95, 95% confidence interval [CI] 0.91-1.00) was significantly greater than for TTE (Kappa 0.85, 95% CI 0.78-0.93) (P < 0.05). The elapsed time for completion of RT3D (14.4 ± 2.8 min) was shorter than for TEE (26.4 ± 4.7 min, P < 0.0001) and TTE (19.0 ± 3.1 min, P< 0.0001). Conclusions: RT3D is fast, accurate, and highly reproducible for assessing MVP.