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Comparison of central and peripheral haemodynamic effects of dilevalol and atenolol in essential hypertension
T C Tham1, B Silke, S H Taylor
1Department of Therapeutics and Pharmacology, Queen's University of Belfast, Northern Ireland.
Insights
A new cardiac output device assessed atenolol and dilevalol in hypertension patients. Dilevalol showed a distinct peripheral vasodilator action compared to atenolol.
Area of Science:
- Cardiovascular Pharmacology
- Medical Devices
Background:
- Essential hypertension management often involves beta-blockers.
- Understanding the distinct cardiovascular effects of different beta-blockers is crucial for optimizing patient care.
Purpose of the Study:
- To evaluate the cardiovascular effects of atenolol and dilevalol in patients with essential hypertension.
- To investigate the peripheral circulatory effects of these two beta-blockers using thermography.
Main Methods:
- Utilized a novel non-imaging echo-Doppler cardiac output device based on attenuated compensation volume flow (ACVF).
- Assessed systemic hemodynamic parameters (blood pressure, heart rate, cardiac output, systemic vascular resistance) and aortic velocity integral.
- Employed thermography and skin thermal clearance to evaluate peripheral circulation changes.
Main Results:
- Both atenolol and dilevalol significantly reduced mean arterial pressure and heart rate.
- Atenolol decreased aortic velocity integral, while dilevalol reduced systemic vascular resistance.
- Both drugs reduced skin temperature and thermal clearance, with more pronounced effects observed with atenolol.
Conclusions:
- Dilevalol's mechanism of action appears to differ partly from atenolol.
- Dilevalol's effects are consistent with a direct peripheral vasodilator action.
- The ACVF device provides a valuable tool for assessing cardiovascular and peripheral circulatory responses to antihypertensive medications.
Abstract:
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.