Variability in arterial diameter and compliance: compliance modulation reserve.

BACKGROUND

Some antihypertensive drugs are known to increase arterial compliance in hypertensives; how far compliance can be increased is unknown.

DESIGN

We studied eight mildly hypertensive patients to determine how far radial artery compliance can be acutely increased, i.e. the extent of the compliance modulation reserve.

METHODS

We evaluated radial artery compliance by a new technique, assessing it throughout the cardiac cycle before and after the intra-arterial infusion of a vasodilator agent (papaverine).

RESULTS

Before papaverine, compliance decreased progressively through diastolic to systolic blood pressure values. This was the case also during the papaverine infusion. However, over the full systolo-diastolic pressure range, compliance was increased by about 40% with papaverine.

CONCLUSIONS

In hypertensive subjects radial artery compliance can be markedly increased on a acute basis, indicating that those antihypertensive drugs that improve compliance have a considerable reserve to act upon.