The left ventricular color M-mode Doppler flow propagation velocity V _p: In vivo comparison of alternative methods including physiologic implications

Three alternative methods have been proposed for determining the "velocity of propagation" (V_p) from color M-mode Doppler transmitral flow images. A quantitative intermethod comparison is performed by using a broad class of images encountered in clinical practice. V_p for 13 subjects was measured by using each of the 3 methods and then statistically compared. Differences among the definitions of V_p generated large differences in its numerical value when computed from the same image. Depending on the choice of method, the value of V_p can vary by as much as 250%. Advantages and limitations of each method are discussed in the context of the physical meaning of V_p. Development of an optimal version of V and consensus on how it should be defined merits further attention. This will require a multidisciplinary approach encompassing physiology, fluid dynamics, image processing, and mathematical modeling.