Oscillatory hyperventilation in severe congestive heart failure secondary to idiopathic dilated cardiomyopathy or to ischemic cardiomyopathy
Kremser, C.B.; O'Toole, M.F.; Leff, A.R.
American Journal of Cardiology 59(8): 900-905
1987
ISSN/ISBN: 0002-9149
PMID: 3825954
DOI: 10.1016/0002-9149(87)91116-7
Accession: 006046671
Thirty-one subjects with chronic congestive heart failure (CHF) were separated into 3 groups according to ventilatory patterns during graded exercise: Group 1-oscillators (n = 6); group 2-intermediate oscillators (n = 14); and group 3-nonoscillators (n = 11). Group 1 patients showed cyclic fluctuations in minute ventilation (change of 30 to 40 liters/min) and arterial PO2 (change of 38.0 .+-. 4.1 mm Hg) and PCO2 (change of 11 .+-. 2.8 mm Hg). The nadir in arterial PO2 occurred at times when wasted ventilatory effort was maximal. The amplitude of ventilatory oscillations in group 1 patients increased in the transition from rest to light exercise and damped with heavy exercise. There was no evidence of alveolar hypoventilation at the nadirs of minute ventilation; arterial PCO2 was always 40 mm Hg or less. Substantial hyperventilation (ventilatory equivalent for CO2 twice normal) occurred with maximal minute ventilation in group 1 patients. Oscillatory hyperventilation correlated with severity of CHF. Maximal oxygen uptake was significantly lower in group 1 (11.7 .+-. 1.1 ml/kg/min) than group 3 (17.9 .+-. 1.8 ml/kg/min) (p < 0.05). Oscillatory hyperventilation during exercise may accompany severe CHF and compounds the inadequate delivery of oxygen by the failing heart.