On the correlation of acoustical sounds and ultrasound velocimetry in the subclavian steal syndrome.

Patients with suspected subclavian steal syndrome were examined by Doppler ultrasonography and by auscultation, particular attention being paid to the velocity profiles and "augmentation bruits" in the vertebral arteries, and the findings being compared with angiography. This was done with the patients at rest and during and after ischemic exercise of the affected arm. The recorded bruits were analyzed for their frequency content and it was found that the bruits in a particular kind of vessel are well characterized by the first moment of the spectrum. A good correlation between the Doppler ultrasound results and the acoustical sound pattern accompanying hyperemic flow was found. The two methods are supplementary and complementary in the non-invasive diagnosis of subclavian steal syndrome. To demonstrate the multifacetted appearances of the syndrome three cases are discussed.