Effect of antihypertensive therapy on the cardiovascular amplifiers

1. In established chronic hypertension the amplifier properties of vessels and heart contribute about 70% to the maintenance of the elevated blood pressure (BP). Recent studies in spontaneously hypertensive rats (SHR) suggest that the structural changes occur very early and their amplifier properties may be critical for the development of hypertension. 2. In patients with primary hypertension, the greater the regression of cardiac and vascular hypertrophy, the slower the subsequent redevelopment of hypertension. Following regression of hypertrophy, the antihypertensive action of moderate regular exercise can maintain BP in the normal range in a proportion of patients. 3. Early treatment of SHR with enalapril greatly reduces the subsequent 'steady-state' BP in SHR. This produces virtually complete regression of vascular hypertrophy, but somewhat lesser degrees of regression of cardiac hypertrophy. 4. These studies serve as models for primary and secondary prevention of hypertension. A strategy based on intermittent drug and non-pharmacological therapy in man may contribute to the secondary prevention of atherosclerosis, in view of the adverse effects on lipid profiles of many antihypertensive drugs.