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AT1 antagonism by eprosartan lowers heart rate variability and baroreflex gain

Karsten Heusser1, Jan Vitkovsky, Roland E Schmieder

  • 1Department of Medicine IV/Nephrology, University of Erlangen-Nuremberg, Krankenhausstrasse 12, 91054, Erlangen, Germany. karsten.heusser@gmx.de

Autonomic Neuroscience : Basic & Clinical
|August 21, 2003
PubMed

Insights

Eprosartan, an angiotensin type 1 (AT1) receptor blocker, reduced heart rate variability (HRV) and baroreflex gain (BRG). This effect is likely due to increased circulating angiotensin II (Ang II) levels.

Area of Science:

  • Cardiovascular Physiology
  • Autonomic Nervous System Regulation

Background:

  • Angiotensin-converting enzyme (ACE) inhibitors reduce mortality in cardiovascular diseases, partly by modulating autonomic control.
  • This modulation is evidenced by increased heart rate variability (HRV) and baroreflex gain (BRG).

Purpose of the Study:

  • To investigate the effects of the angiotensin type 1 (AT1) receptor blocker eprosartan on HRV and BRG.

Main Methods:

  • A double-blind, randomized, cross-over study involving 25 males.
  • Participants received eprosartan (600 mg/day) or placebo for 7 days, with a wash-out period.
  • Arterial blood pressure (AP) and electrocardiogram (ECG) were recorded; HRV, arterial blood pressure variability (APV), and baroreflex gain (BRG) were calculated.

Main Results:

  • Eprosartan slightly increased heart rate (HR) and markedly increased circulating angiotensin II (Ang II) levels.
  • Eprosartan diminished total HRV power and BRG.
  • The low/high frequency (LF/HF) ratio of HRV and APV remained unchanged.

Conclusions:

  • AT1 antagonism with eprosartan decreases HRV and BRG.
  • This reduction is hypothesized to result from elevated circulating Ang II.
  • Further research is needed to determine if AT1 blockers acting within the blood-brain barrier (BBB) have different effects.
Abstract

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