High-resolution real-time ultrasound of the carotid bifurcation in patients with hyperactive carotid sinus syndrome.

The carotid bifurcations and the common carotid arteries of 36 patients with the diagnosis hyperactive carotid sinus syndrome (HCSS) were investigated by continuous wave (CW) Doppler ultrasonography and high-resolution real-time B-scan. Using these non-invasive tests, the functional impact of luminal stenosis and the morphological changes resulting from arteriosclerotic deformities could be established. Significant differences were found in comparison with a reference group of 199 patients with a high risk of arteriosclerosis. In the HCSS group, 5 patients had a stenosis of more than 50% at the origin of the internal carotid artery on both sides, or on one side in combination with large plaques or a complete occlusion on the contralateral side. Seventy-five per cent of patients in the HCSS group, as compared to only 23.5% of the control group, had effective arteriosclerotic changes in the carotid bifurcation on both sides; 4 patients had such changes only unilaterally. Marked additional bilateral arteriosclerotic depositions were detected in the common carotid arteries of 17 patients (47.2%). In 5 patients no arteriosclerotic lesions were detectable in the carotid bifurcations, but marked changes were found in both common carotid arteries. These data indicate that bilateral arteriosclerotic changes in the carotid bifurcations and/or the common carotid arteries represent an important pathophysiological factor for the development of an HCSS.