Research

Coronary artery bypass surgery and longitudinal evaluation of the autonomic cardiovascular function

Pedro PS Soares¹, Adalgiza M Moreno², Sérgio LD Cravo³ and Antonio CL Nóbrega^4*

• * Corresponding author: Antonio CL Nóbrega anobrega@urbi.com.br

Author Affiliations

¹ Research Associate, Department of Physiology and Pharmacology, Universidade Federal Fluminense, Niterói, RJ, Brazil

² Physical Therapy Master Program, Centro Universitário do Triângulo Mineiro, Uberlândia, MG, Brazil

³ Associate Professor, Department of Physiology, Universidade Federal de São Paulo, São Paulo, SP, Brazil

⁴ Professor, Department of Physiology and Pharmacology, Universidade Federal Fluminense, Niterói, RJ, Brazil

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Critical Care 2005, 9:R124-R131 doi:10.1186/cc3042

Published: 26 January 2005

Abstract

Introduction

Imbalance in autonomic cardiovascular function increases the risk for sudden death in patients with coronary artery disease (CAD), but the time course of the impact of coronary artery bypass grafting (CABG) on autonomic function has been little studied. Thus, the purpose of the present study was to determine the effects of the CABG on the cardiovascular autonomic function.

Methods

Patients undergoing CABG (n = 13) and two matched control groups (patients with CAD who refused surgical treatment [n = 9], and healthy volunteers [n = 9]) underwent a prospective longitudinal study consisting of autonomic evaluation before and after (3, 6, 15, 30, 60, and 90 days) surgery, including measurement of heart rate variability (HRV), respiratory sinus arrhythmia (RSA), and Valsalva maneuver.

Results

After CABG there was a decrease in, and a later recovery of, (1) the HRV in the time domain and in the frequency domain, (2) RSA, and (3) Valsalva maneuver.

Conclusions

CABG caused an impairment, reversible after 60 days, of cardiovascular autonomic function, with a maximal decrease on about the sixth day after surgery.