Hæmodynamics in Essential Hypertension

ACCORDING to present-day concepts the raised blood pressure of essential hypertension is thought to be due to a more or less parallel increase in vascular resistances in all the important regions of the body, while cardiac output remains unchanged1. This view is based on measurements of flow of blood through the whole upper extremity2 or through its skin3, which gave values not exceeding those of normotensive subjects, as would be expected should the rise in blood pressure be due to a localized increase of resistance, for example, in the splanchnic area. However, flow of blood in skin and muscle might be changed in opposite directions, and, therefore, such isolated investigations might give misleading information in this respect.