Effects of antihypertensive agents on carotid pulse contour in humans

Area of Science:

• Cardiovascular Physiology
• Pharmacology
• Hypertension Research

Background:

• Arterial wave reflections (AWR) and carotid pulse pressure (PP) are key indicators of cardiovascular risk.
• Antihypertensive agents can influence central hemodynamics, but their effects on AWR vary.
• Understanding these effects is crucial for optimizing hypertension management.

Purpose of the Study:

• To compare the effects of atenolol and nitrendipine on AWR and carotid PP in hypertensive patients.
• To assess how these agents alter the timing of wave reflections relative to ventricular ejection.
• To determine if peripheral blood pressure reduction correlates with central hemodynamic improvements.

Main Methods:

• Noninvasive carotid tonometry was used to record pressure waveforms.
• Arterial wave reflections were quantified using the augmentation index (delta P/PP).
• Travel time of reflected waves (delta tp) and aortic pulse wave velocity (PWV) were measured.

Main Results:

• Both atenolol and nitrendipine reduced brachial blood pressure and carotid PP.
• Nitrendipine significantly reduced the augmentation index (delta P/PP), unlike atenolol.
• Both agents increased reflected wave travel time (delta tp) and decreased aortic PWV; nitrendipine also decreased left ventricular ejection time (LVET).

Conclusions:

• Nitrendipine demonstrates a more pronounced effect on central arterial pressure waveforms than atenolol at equivalent peripheral blood pressure reduction.
• Nitrendipine improves the timing between ventricular ejection and arterial wave reflections, potentially offering greater cardiovascular protection.
• These findings highlight the importance of considering central hemodynamic effects when selecting antihypertensive therapies.