Doppler analysis of flow velocity profile at the aortic root.

This study of aortic root flow velocity profiles suggests that the flow velocity pattern is parabolic rather than flat as has been widely supposed. To analyze the distribution of flow velocity, a special ultrasound pulsed Doppler velocity flow meter, with a direct probe on the aortic wall, was designed. Sixteen patients, none with a diagnosis of aortic valve disease, were examined just before undergoing open heart surgery. Parabolic velocity patterns were always found, and it was determined that the parabola was skewed rightward toward the anterior wall. Furthermore, it was shown that the flow velocity vector was initially directed toward the commissure of the right coronary and the noncoronary cusps.