Semiquantitation of aortic regurgitation by pulsed Doppler examination of the subclavian artery velocity contour.

The reflux of aortic regurgitation causes an increased and longer diastolic reverse flow in the aorta and its branching vessels as compared to the normal flow contour. The changes of the aortic flow are related to the severity of aortic regurgitation and can be demonstrated by Doppler ultrasound. As Doppler examinations are often restricted in the aorta, a prospective study was designed to determine the feasibility and accuracy of Doppler measurements in the subclavian artery for the identification of severe forms of aortic regurgitation. Fifty-five patients with and 40 patients without aortic regurgitation were examined both by aortography and pulsed Doppler flow analysis of the subclavian artery. Two age groups were differentiated: patients below and those over 60 years of age, respectively. A high quality Doppler signal was recorded in all patients. In patients below 60 years, the best predictors of severe aortic regurgitation proved to be a pandiastolic reverse flow and an increased regurgitant fraction (77%) with a sensitivity of 100% and specificity of 75% and 92%, respectively. Since a pandiastolic reverse flow was detected in most patients in the control group over 60 years, it was not indicative of aortic regurgitation in these cases. However, an increased maximal diastolic velocity (> -37 cm/s) identified severe forms of aortic regurgitation in this age group with a sensitivity of 89% and a specificity of 100%. Therefore, severe forms of aortic regurgitation may be reliably identified by analysing the subclavian artery Doppler spectrum. In conclusion, the method is a useful adjunctive technique to other Doppler echocardiographic methods to assess the severity of aortic regurgitation.