[Periodic breathing during physical exercise: expression of a form of ventricular interdependence?]

Periodic breathing may be observed in patients with severe congestive heart failure during exercise. We describe a patient with such a breathing pattern. We noted that nadir of oxygen consumption cycles slightly preceded the nadir of ventilation cycles, suggesting that this breathing pattern is due to cardiac output periodic changes, possibly through an interplay among the two ventricles and the pulmonary blood reservoir.