Oscillatory ventilation during exercise in patients with chronic heart failure: clinical correlates and prognostic...

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.

Cardiology division at tertiary-care hospital.

We studied 323 patients with chronic heart failure and left ventricular ejection fraction (LVEF) < or = 40%.

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 (E) at rest that persist during effort lasting > or = 60% of the exercise duration, with an amplitude > or = 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 (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 E/CO(2) slope (p < 0.0001) and lower LVEF (p < 0.0001), mitral Doppler early deceleration time (p < 0.01), and peak O(2) (p < 0.0001). EOV was more frequent in nonsurvivors than in survivors (28% vs 9%, p < 0.01). Multivariate analysis revealed peak O(2) (chi(2), 51.5; p < 0.0001), EOV (chi(2), 45.4; p < 0.0001), and LVEF (chi(2), 20.6; p < 0.0001) as independent predictors of major cardiac events.

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.