Real Time Triplane Echocardiography in the Assessment of the Functional Area of Prosthetic Aortic Valves: Reliability and Feasibility

Abstract

Our study is aimed at evaluating the feasibility and reliability of a simple method for the measurement of the functional area of prosthetic aortic valves (EOA). Three-dimensional echocardiography has proven accurate for left ventricular volume, stroke volume, and aortic valve area measurement. We studied the feasibility and reliability of real time simultaneous triplane echocardiography (RT3P) for assessing the EOA with a fast formula based on the principle of continuity equation, in which we replaced Doppler-derived stroke volume (SV) with SV directly measured with RT3P. EOA of prosthetic aortic valves were measured in 23 consecutive patients requiring periodical follow up. EOA was calculated using Doppler continuity equation (DCE) and the RT3P method by replacing Doppler-derived SV with SV measured with real time triplane echocardiography. We compared functional areas obtained with the two methods with the prosthetic area indicated in the manufacturer's specifications and with the mean transprosthetic gradient. Both methods had a good correlation with the area indicated by the manufacturer. RT3P revealed an inverse correlation between functional area and mean gradient that was better than DCE (P = 0.0359). Inter- and intraobserver variability was not different between the two methods. Execution time was significantly shorter for RT3P. RT3P is a simple method that can be performed quite rapidly, and can complement the overall assessment of prosthetic valve function. Further studies can confirm our technique.