Evidence that the Effect of Beta-adrenergic Blockade on the Haemodynamic Response of Hypertensive Patients to Exercise is not solely Rate-dependent

Abstract

To achieve the same heart rate after β-adrenergic blockade as before, hypertensive patients performed higher work loads. Cardiac output was unaltered, but cardiac work was reduced both by a decrease in peripheral resistance and by prevention of any increase in myocardial contractility on exercise. This led to unmasking of the Frank–Starling mechanism.