Semi-automated analysis of Color M-mode echocardiographic images for determining transmitral pressure gradients using a simplified Euler equation

We hypothesize that a simplified version of the Euler equation (SEE) utilizing differences in velocity over a distance and time as obtained by Color Doppler M-mode (CMM) echocardiography can appropriate actual peak transmitral pressure gradients (DeltaP(TM)). Methods: In 14 patients undergoing open-heart surgery, DeltaP(TM) was measured under various hemodynamic conditions using 2 high fidelity transducers, 5cm apart. Transesophageal CMM images were simultaneously acquired and a customized image analysis application was used to abstract spatiotemporal velocity characteristics. Using both the SEE and a simplified Bernoulli equations, DeltaP(TM) were determined and compared to the actual DeltaP(TM) Results. While the simplified Bernoulli equation resulted in a poor estimate (y=0.075x+0.71, r=0.45), the DeltaP(TM) obtained using the SEE correlated strongly (y=0.79x+0.48, r=0.91) with the actual measurements. Conclusions: Semi-automated analysis,sis of CMM images using a SEE can accurately estimate actual DeltaP(TM).