Biofeedback treatment increases heart rate variability in patients with known coronary artery disease
Received 11 March 2003; accepted 15 August 2003.
Abstract
Objectives
To determine if cardiorespiratory biofeedback increases heart rate variability (HRV) in patients with documented coronary artery disease (CAD).
Background
Diminished HRV has been associated with increased cardiac morbidity and mortality. Evidence suggests that various lifestyle changes and pharmacologic therapies can improve HRV. The objective of this study was to determine if biofeedback increases HRV in patients with CAD.
Methods
Patients with established CAD (n = 63; mean age, 67 years) were randomly assigned to conventional therapy or to 6 biofeedback sessions consisting of abdominal breath training, heart and respiratory physiologic feedback, and daily breathing practice. HRV was measured by the standard deviation of normal-to-normal QRS complexes (SDNN) at week 1 (pretreatment), week 6 (after treatment), and week 18 (follow-up).
Results
Baseline characteristics were similar for the treatment and control groups. The SDNN for the biofeedback and control groups did not differ at baseline or at week 6 but were significantly different at week 18. The biofeedback group showed a significant increase in SDNN from baseline to week 6 (P < .001) and to week 18 (P = .003). The control subjects had no change from baseline to week 6 (P = .214) and week 18 (P = .27).
Conclusions
Biofeedback increases HRV in patients with CAD and therefore may be an integral tool for improving cardiac morbidity and mortality rates.
aCalifornia School of Professional Psychology at Alliant International University, San Diego, Calif, USA
bScripps Center for Integrative Medicine, Scripps Green Hospital, and Scripps Clinic, San Diego, Calif, USA
Reprint requests: Richard N. Gevirtz, Alliant International University, 10455 Pomerado Road, San Diego, CA 9213, USA.
ABSTRACT