Comparison of central and peripheral haemodynamic effects of dilevalol and atenolol in essential hypertension.

A new non-imaging echo-Doppler cardiac output device that works on the principle of attenuated compensation volume flow (ACVF), has been used to assess the cardiovascular effects of atenolol and dilevalol in 24 patients with essential hypertension. Compared with the baseline, one month of atenolol reduced systemic mean arterial blood pressure (12 mmHg; P less than 0.01), heart rate (-24 bpm; P less than 0.001), aortic velocity integral (-2.1 cm/sec; P less than 0.01) without a change in cardiac output or systemic vascular resistance. Dilevalol reduced systemic mean arterial pressure (-12 mmHg; P less than 0.01) and heart rate (-13 bpm; P less than 0.01), without a change in cardiac output or aortic velocity integral; systemic vascular resistance fell (-149 dyne/sec; P less than 0.01). Thermography and skin thermal clearance techniques were used to assess the effects of each compound on the peripheral circulation; both compounds reduced skin temperature and thermal clearance but the changes were more marked for atenolol than dilevalol. These results suggest that the mechanism of action of dilevalol is, in part, different from atenolol and would be compatible with a direct vasodilator action on the peripheral vasculature.