Isometric exercise before and after nadolol treatment in uncomplicated essential hypertension.

Systolic, diastolic and mean arterial pressure (SAP, DAP, MAP), heart rate (HR) and tension time index (TTI) were evaluated in 20 uncomplicated hypertensives and in 20 normotensives at rest and during isometric exercise, performed by handgrip (HG). In the hypertensive population the same parameters were evaluated also after two and six weeks of treatment with a beta-blocking agent, nadolol, given in a single daily dose. In all cases isometric exercise induced a significant increase of SAP, DAP, MAP, HR and TTI and this increase was more relevant in hypertensives than in controls. In the hypertensive population, nadolol was effective in lowering arterial pressure at rest, and significantly reduced the levels of SAP, DAP, MAP, HR and TTI reached at the end of the HG test. Moreover, the increments of the investigated parameters induced by isometric exercise were significantly reduced after nadolol. The results suggest that nadolol, unlike other beta-blocking agents, exerts a "protective" action against the hazardous increments of blood pressure which may occur in the daily life of hypertensive subjects during involuntary isometric exercises, and which could trigger dangerous cardiovascular complications.