Stroke volume--pulse pressure relationships in borderline hypertension: a possible indicator of decreased arterial compliance.

Resting invasive haemodynamic measurements were performed on 354 volunteers, 168 normals, and 186 with borderline hypertension. To test the hypothesis that patients with borderline hypertension would have a decrease in the compliance of their arterial system, the relationship of stroke volume (SV) and stroke volume index (SVI) to pulse pressure (PP) in the two groups was examined. Theoretically, as compliance decreases, there should have been a stronger relationship between SV or SVI and PP. In the sample studied, SV and SVI were significantly related to PP in borderline hypertensive patients (P less than 0.005), but not in normotensive patients. When the samples were divided into tertiles of low, middle, and high SV, the borderline hypertensive patients had higher PP with higher SV (P less than 0.01), while the normals did not. It is concluded that there appear to be significant differences between normals and patients with borderline hypertension in the relationship of SV and SVI to PP. This can be interpreted as evidence to support the existence of an abnormality in arterial compliance in borderline hypertension.