Abstract 19286: Periodic Breathing During Asleep and Exercise in Patients with Heart Failure
Backgrounds: Central sleep apnea (CSA) and exercise oscillatory ventilation (EOV) might both originate from an instability in feedback peripheral and central chemoreflex control of ventilation. However, the relation between CSA and EOV in patients with heart failure is still unknown.
Methods: In 70 patients with heart failure (ejection fraction<45%), cardiorespiratory polygraphy and cardiopulmonary exercise test (CPX) were performed. EOV was defined as 3 or more regular oscillatory fluctuations in ventilation. In 10 patients with EOV, CPX and cardiorespiratory polygraphy were studied twice after intensive treatment of heart failure.
Results: EOV was observed in 21 of 70 patients (30%, cycle length of EOV: 83±26 sec). The cycle length of EOV was similar to that of CSA (r=0.88, p<0.001). EOV was more frequent in patients with moderate to severe sleep apnea (apnea-hypopnea index (AHI)≥15/h) than in patients with mild sleep apnea (AHI 5–15/h) or without sleep apnea (AHI<5/h) (51% vs. 7% and 5%, respectively). In contrast, EOV was not observed in patients who had moderate to severe sleep apnea and central apnea index (CAI) less than 10/h. In subgroup of patients who were studied twice, EOV was abolished in 4 patients and sustained in 6 patients. In patients with abolished EOV, AHI and CAI were decreased, respectively (30±9→8±5/h, p<0.05, 24±9→3±4/h, p<0.05). In patients with sustained EOV, however; AHI and CAI were unchanged (29±4→24±11/h, ns; 19±6→18±8/h, ns). Univariate analysis showed age and EOV were significant predictors of CAI, but other clinical parameters were not (table). Notably, multivariate analyses revealed that EOV was a common independent predictor of CAI and AHI (both, p<0.001).
Conclusion: These findings suggest that EOV is an important predictor of moderate to severe CSA in patients with heart failure. Table
- © 2010 by American Heart Association, Inc.