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Cardiac Response to β-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis
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Cardiac Response to β-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Published on: May 19, 2021

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Relationship between chronotropic incompetence and β-blockers based on changes in chronotropic response during

Nami Takano1, Haruhito Takano2, Taira Fukuda3

  • 1Department of Cardiovascular Medicine, The University of Tokyo Hospital, 7-3-1Hongo, Bunkyo-Ku, Tokyo 113-8655, Japan.

International Journal of Cardiology. Heart & Vasculature
|August 9, 2017
PubMed

Insights

Chronotropic incompetence, an impaired heart rate response to exercise, can improve with cardiac rehabilitation. Beta-blockers significantly influence the metabolic chronotropic relationship during exercise testing.

Area of Science:

  • Cardiology
  • Exercise Physiology

Background:

  • Chronotropic incompetence (CI) is a common condition in cardiovascular disease patients, characterized by an inadequate heart rate (HR) increase during physical activity.
  • Assessing CI is crucial for optimizing exercise capacity and rehabilitation outcomes in these individuals.

Purpose of the Study:

  • To evaluate changes in chronotropic response (CR) during cardiopulmonary exercise testing (CPET) in patients undergoing cardiac rehabilitation.
  • To investigate the impact of beta-blocker medication on CR and the metabolic chronotropic relationship (MCR).

Main Methods:

  • Patients with CI undergoing cardiac rehabilitation performed CPET.
  • The metabolic chronotropic relationship (MCR) was calculated at four exercise stages using the Wilkoff model.
  • Improvement in CR was defined as an increase in MCR at three or more stages.

Main Results:

  • Patients with elevated BNP levels exhibited lower MCR values across all exercise stages.
  • Beta-blocker use was prevalent in patients showing improved peak VO2 and anaerobic threshold (AT), and in those with improved CR.
  • The MCR pattern differed based on beta-blocker use: MCR-AT was lower than MCR-Rc in non-users, and higher in users.

Conclusions:

  • An attenuated HR response during exercise may be more pronounced in the initial stages.
  • Comparing MCR-AT and MCR-Rc effectively identifies the influence of beta-blockers on HR response during CPET.
Abstract

Keywords:
Cardiac rehabilitationCardiopulmonary exercise testingChronotropic incompetenceMetabolic chronotropic relationshipβ-blocker

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