Colour Doppler imaging of partial subclavian steal syndrome.

The case of a 67-year-old woman with symptoms related to the vertebro-basilar system and blood pressure difference of the upper extremities is presented. Colour-Doppler imaging (CDI) with additional spectral tracing revealed partial subclavian steal syndrome with retrograde flow in the left vertebral artery during systole, which could be significantly enhanced by reactive hyperemia after left arm exercise. Angiography confirmed a high-grade stenosis of the proximal subclavian artery and balloon angioplasty was performed. Noninvasive follow-up by CDI demonstrated regular antegrade vertebral artery flow at rest, but minimal retrograde systolic flow after left arm exercise.