Transcutaneous aortovelography: reproducibility in adults and children.

Transcutaneous aortovelography (TAV), a new ultrasonic technique for measuring instantaneous mainstream blood velocity in the aorta, is described. The technique uses the Doppler shift principle. The highest local blood velocity within the aortic arch can be recorded from a transducer placed in the suprasternal notch. Inspection of the systolic complexes recorded allows measurement of peak velocity, systolic complex area (proportional to ejected stroke volume), mean (time averaged) blood velocity and initial systolic acceleration. Formal analysis of variance was performed on measurements made by the five observers on 11 healthy adults and by 2 observers on 10 healthy children. Coefficients of variation of from 4 to 8% were found of all variables other than acceleration where the variation was up to 16%. Peak velocities in adults ranged from 97 to 130 cm/sec and were higher in children.