Noninvasive ultrasound evaluation of the vertebral artery in hypertension

Abstract

Background and Purpose. Surgical decompression of the vascular loop of the vertebral artery (VA) at the left lateral medulla can reduce blood pressure (BP) in hypertension, and a larger diameter of the left VA has been found in hypertensive patients. Noninvasive evaluation of the VA in hypertension may assist selecting patients for more appropriate diagnosis and treatment. Duplex ultrasonography is used to study the relationship between VA diameter and BP. Methods. A retrospective review of VA duplex ultrasonography was performed in 112 consecutive patients who were sent to the neurovascular laboratory at the Wake Forest University School of Medicine during a 2-month period. All measurements (BP, pulse rate, peak systolic velocity [PSV], end diastolic velocity [EDV], and diameters of both VAs) were determined according to standardized protocols. Left-right comparisons of VA diameters, PSV, and EDV between hypertensives and normotensives were performed by the matched-pairs analysis techniques. Results. Fifty-five women and 57 men with a mean age of 64.8 years were studied. Hypertension was present in 65.2% of all patients. The age-adjusted mean left VA diameter was significantly higher than that of the right VA with an age-adjusted average differences of 0.2 mm (P = .03) for hypertensives compared to 0.04 mm (P = .75) for normotensives. No significant differences were observed in either PSV or EDV. Conclusions. Differences in left-right VA diameter in hypertensive subjects may be a previously unrecognized component of the vascular disturbances associated with the disease and represent an additional criterion for identifying those who may benefit from surgical and medical management.