Orthostatic Hypertension

Abstract

See related article, pp 167–173 Orthostatic hypertension (OHT) is beneath the radar of many health care professionals. In the clinic, it is generally both unexpected and counterintuitive. After recheck, it may sometimes regress toward the mean. However, at other times the OHT can be dramatic and persistent. Nevertheless, our knowledge about its causes and significance remains circumscribed. It is in many ways the last hemodynamic frontier. Recently, there has been increasing interest in OHT and its possible consequences on health. The spectrum of degree and clinical context of OHT is very broad.1 In some cases, it can be a dramatic physical manifestation of 50 mm Hg or more in a disorder such as baroreflex failure. In other situations, it may only be an incidental physical finding. OHT is usually defined as an increase in blood pressure with upright posture or tilt, but precise criteria have not been established. Furthermore, few studies have entailed direct measurement of blood pressure in people with OHT. Such measurements would more faithfully reflect intraarterial pressure and would avoid the introduction of potential artifacts. Sphygmomanometers can underestimate blood pressure when it is perturbed by pressor reflexes, such as those engaged by upright posture, or if it is increased by pressor agents. Therefore, the magnitude of the blood pressure increase after standing might be even larger than is generally reported in patients with OHT. OHT has been long recognized. Some of the most thoughtful early studies were conducted by David Streeten …