Background: Exercise oscillatory ventilation (EOV) is a consequence of ventilatory control system instability and is commonly observed in patients with advanced heart failure (HF); it is associated with adverse prognosis. The goal of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) on oscillatory ventilation as quantified by a proposed EOV score. Methods and Results: Consecutive patients with HF (N = 35) who underwent clinically indicated CRT, cardiopulmonary exercise testing and carbon dioxide (CO2) chemosensitivity by rebreathe before and 4–6 months after CRT were included in this post hoc analysis. With CRT, EOV scores improved in 22 patients (63%). In these patients, left ventricular ejection fraction, left atrial volume, brain natriuretic peptide concentration, and CO2 chemosensitivity significantly improved after CRT (P < 0.05). Furthermore, minute ventilation per unit CO2 production significantly decreased, and end-tidal CO2 increased at rest and at peak exercise post-CRT. Multiple regression analysis showed only the change of CO2 chemosensitivity to be significantly associated with the improvement of the EOV score (b = 0.64; F = 11.3; P = 0.004). In the group without EOV score improvement (n = 13), though left ventricular ejection fraction significantly increased with CRT (P = 0.015), no significant changes in ventilation or gas exchange were observed. Conclusion: The EOV score was mitigated by CRT and was associated with decreased CO2 chemosensitivity.
- Exercise oscillatory ventilation
- heart failure, CO chemosensitivity
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine