Real-time observation of intra- and extracardiac blood flow profile in man using instantaneous B-mode and multichannel Doppler echocardiography.

We observed instantaneous blood flow velocity profiles at the right and left ventricular outflow tracts, the ascending aorta, and the lower thoracic aorta in human subjects using a newly devised method of real-time multichannel Doppler echocardiography. In 20 apparently healthy subjects, the blood flow velocity profile was successfully obtained in all cases at the right and left ventricular outflow tracts--in 13 cases at the ascending aorta, in 12 cases at the aortic arch, and in ten cases at the lower thoracic aorta. The configuration of the profile was almost flat during systole at the left ventricular outflow tract, the ascending aorta, and the descending aorta. The profile was triangular at the right ventricular outflow tract, where the velocity was faster at the ventricular septal side than at the free wall side, and it was also triangular at the aortic arch, where the velocity was faster at the inner side of the arch than at the outer side. These observations were very similar to those reported by others in previous experimental studies. Thus, the present study demonstrates that it is possible to record noninvasively the instantaneous blood flow velocity profile in humans using this new Doppler echocardiographic instrument.