Oscillatory ventilation during exercise in patients with chronic heart failure -: Clinical correlates and prognostic implications

Study objectives: Although breathing disorders are often found in patients with chronic heart failure, exertional oscillatory ventilation (EOV) has been occasionally described. The aim of this study was to determine the prevalence, clinical characteristics, and outcome of patients with chronic heart failure and EOV. Setting: Cardiology division at tertiary-care hospital. Study population: We studied 323 patients with chronic heart failure and left ventricular ejection fraction (LVEF) less than or equal to 40%. Measurements and results: All patients performed a symptom-limited cardiopulmonary exercise test and were followed up for 22 +/- 11 months (mean +/- SD). EOV was defined as cyclic fluctuations in minute ventilation ((V) over dot E) at rest that persist during effort lasting less than or equal to 60% of the exercise duration, with an amplitude greater than or equal to 15% of the average resting value. Patients with EOV (12%), as compared to those without, showed higher New York Heart Association (NYHA) class (p < 0.05) and lower LVEF (p < 0.0001) and peak oxygen consumption ((V) over dot O-2.) [p < 0.0001]. During the follow-up period, 53 patients died or underwent urgent cardiac transplantation; this group showed higher NYHA class (p < 0.05) and (V) over dot E/(V) over dot CO2 slope (p < 0.0001) and lower LVEF (p < 0.0001), mitral Doppler early deceleration time (p < 0.01), and peak (V) over dot O-2 (p < 0.0001). EOV was more frequent in nonsurvivors than in survivors (28% vs 9%, p < 0.01). Multivariate analysis revealed peak (V) over dot O-2 (χ(2), 51.5; p < 0.0001), EOV (chi(2), 45.4; p < 0.0001), and LVEF (χ(2), 20.6; p < 0.0001) as independent predictors of major cardiac events. Conclusions: EOV is not unusual in patients with chronic heart failure, and is associated with worse clinical status, cardiac function, and exercise capacity. EOV is a powerful predictor of poor prognosis and, consequently, it may be considered a valuable guide in the management of patients with chronic heart failure and should suggest a more aggressive medical treatment policy when detected.