Skip Navigation LinksHome > October 2013 - Volume 45 - Issue 10 > High-Intensity Interval Exercise Improves Vagal Tone and Dec...
Medicine & Science in Sports & Exercise:
doi: 10.1249/MSS.0b013e3182967559
Clinical Sciences

High-Intensity Interval Exercise Improves Vagal Tone and Decreases Arrhythmias in Chronic Heart Failure

GUIRAUD, THIBAUT1,2; LABRUNEE, MARC1,3,4; GAUCHER-CAZALIS, KEVIN1; DESPAS, FABIEN1,3,5; MEYER, PHILIPPE6; BOSQUET, LAURENT7; GALES, CELINE1; VACCARO, ANGELICA1; BOUSQUET, MARC2; GALINIER, MICHEL1,3; SéNARD, JEAN-MICHEL1,3,5; PATHAK, ATUL1,3,5

Collapse Box

Abstract

Purpose: Autonomic dysfunction including sympathetic activation and vagal withdrawal has been reported in patients with chronic heart failure (CHF). We tested the hypotheses that high-intensity interval exercise (HIIE) in CHF patients would enhance vagal modulation and thus decrease arrhythmic events.

Methods: Eighteen CHF patients underwent a baseline assessment (CON) and were then randomized to a single session of HIIE and to an isocaloric moderate-intensity continuous exercise (MICE). We evaluated the HR, HR variability parameters, and arrhythmic events by 24-h Holter ECG recordings after HIIE, MICE, and CON sessions.

Results: We found that HR was significantly decreased after HIIE (68 ± 3 bpm, P < 0.01) when compared with CON and MICE values (71.1 ± 2 and 69 ± 3 bpm, respectively). HIIE led to a significant increase in normalized high-frequency power (35.95% ± 2.83% vs 31.56% ± 1.93% and 24.61% ± 2.62% for CON and MICE, respectively, P < 0.01). Both exercise conditions were associated with an increase in very low frequency power comparative to CON. After HIIE, premature ventricular contractions were significantly decreased (531 ± 338 vs 1007 ± 693 and 1671 ± 1604 for CON and MICE, respectively, P < 0.01). An association was found between the changes in premature ventricular contraction and the changes in low-frequency/high-frequency ratio (r = 0.66, P < 0.01) in patients exposed to HIIE.

Conclusion: We demonstrate that a single session of HIIE improves autonomic profile of CHF patients, leading to significant reductions of HR and arrhythmic events in a 24-h posttraining period. Cardioprotective effects of HIIE in CHF patients need to be confirmed in a larger study population and on a long-term basis.

© 2013 American College of Sports Medicine

Login

Article Tools

Share

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us