Effects of physical exercise on the autonomic nervous system in patients with coronary artery disease: a systematic review

ABSTRACT

Background

Imbalance in autonomic modulation can occur after a cardiac event, which can lead to deleterious consequences. Exercise has proven to be a therapy which affects this modulation and can be assessed through heart rate variability (HRV).

Areas covered

The objective of this systematic review was to investigate the effects of physical exercise on heart rate variability in individuals with coronary artery disease (CAD). The PubMed, PEDro, Scielo, Lilacs and Cochrane databases were systematically searched, for articles which performed supervised exercises in phase II of cardiac rehabilitation in patients with CAD.

Expert opinion

Given the differences between studies on interventions and population characteristics, it is difficult to justify similarities or divergences in terms of results. In addition to the variation in sample size, intervention duration, carrying out an additional program at home, and patients with different clinical presentations, it can be inferred that responses to exercise may vary for certain types/clinical profile of individuals with CAD. Thus, it is necessary to carry out more studies with greater methodological rigor, greater standardization of the variables studied and the evaluation forms, in order to increase the veracity of the results and the consequent clinical relevance and therapeutic application.

KEYWORDS:

• Autonomic nervous system
• cardiac rehabilitation
• coronary artery disease
• exercise
• exercise therapy
• heart disease

Article highlights

• To evaluate non-invasively the autonomic function through the heart rate variability in patients with coronary artery disease is one of the targets after therapy in an outpatient setting.

• Physical exercise has strong benefits and consequences in patients with coronary artery disease, however studies with high methodological quality are still scarce.

• It is necessary that controlled and randomized clinical trials of higher methodological quality be encouraged, addressing in detail the way of assessing heart rate variability, sample size, as well as blinding the evaluator and the results, contributing to further clarification about the dose/response of the patient physical training.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest or financial conflict with the subject or materials discussed in the manuscript. This includes jobs, consultancies, fees, ownership of shares or options, expert testimony, concessions or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose. 

Additional information

Funding

This paper was funded by National Council for Scientific and Technological Development (CNPq), CNPq UNIVERSAL-432865/2016-0, CNPq UNIVERSAL-428841/2018-0 and Coordination for the Improvement of Higher Education Personnel - Brazil (CAPES) - Financing Code 001; PROCAD (CAPES) 88881.068409.2014.01; Support from the Coordination for the Improvement of Higher Education Personnel - Brazil (CAPES) - Financing Code 001 and from the Foundation for the Support of Science and Technology of the State of Pernambuco.