Respiratory control during exercise in patients with cardiovascular disease.

The pathophysiologic mechanism for exertional dyspnea, the main symptom of patients with heart failure, has not been fully clarified. To determine the relationship between exercise hyperpnea and the lactic acidosis in patients with heart failure, we evaluated ventilation during incremental exercise both below and above the lactic acidosis threshold in 16 normal subjects and in 48 patients with cardiovascular disease while expired gas was analyzed continuously. The peak oxygen uptake and oxygen uptake at the lactic acidosis threshold decreased significantly as the New York Heart Association (NYHA) functional class severity increased. the slope of the increase in ventilation to the increase in oxygen uptake (delta VE/delta VO2) at work rates below the lactic acidosis threshold did not differ between normal subjects and patients with heart failure. Above the lactic acidosis threshold, however, the slope of delta VE/delta VO2, which was higher than that below the lactic acidosis threshold in each of four groups, was steeper in patients in NYHA Class II (60.8 +/- 17.9) and Class III (66.5 +/- 21.2) when compared with that in the normal subjects (46.6 +/- 13.5) or the patients in NYHA Class I (46.1 +/- 10.3). The lactic acidosis caused by decreased oxygen transport to working muscles accounts for the higher ventilation during exercise in cardiac patients. These data suggest that the increased ventilation during exercise, which must be related to exertional dyspnea, in patients with cardiovascular disease is primarily the consequence of a stimulus to regulate arterial pH.

[1]  J. E. Hansen,et al.  Principles of Exercise Testing and Interpretation , 1994 .

[2]  D. Paterson.  Potassium and ventilation in exercise. , 1992, Journal of applied physiology.

[3]  K. Wasserman,et al.  The work-rate-dependent effect of carbon monoxide on ventilatory control during exercise. , 1991, Respiration physiology.

[4]  K. Wasserman,et al.  Evidence that the metabolic acidosis threshold is the anaerobic threshold. , 1990, Journal of applied physiology.

[5]  R. Casaburi,et al.  Metabolic acidosis during exercise in patients with chronic obstructive pulmonary disease. Use of the V-slope method for anaerobic threshold determination. , 1988, Chest.

[6]  K. Wasserman.  The Dickinson W. Richards lecture. New concepts in assessing cardiovascular function. , 1988, Circulation.

[7]  M. Higginbotham,et al.  Increased exercise ventilation in patients with chronic heart failure: intact ventilatory control despite hemodynamic and pulmonary abnormalities. , 1988, Circulation.

[8]  B. Whipp,et al.  Control of ventilation during exercise in patients with central venous-to-systemic arterial shunts. , 1988, Journal of applied physiology.

[9]  B. Whipp,et al.  A new method for detecting anaerobic threshold by gas exchange. , 1986, Journal of applied physiology.

[10]  D. M. Band,et al.  The effect of potassium on carotid chemoreceptor activity and ventilation in the cat. , 1985, Respiration physiology.

[11]  K. Wasserman.  The anaerobic threshold measurement to evaluate exercise performance. , 2015, The American review of respiratory disease.

[12]  B. Whipp,et al.  Excercise physiology in health and disease. , 1975, The American review of respiratory disease.

[13]  K. Wasserman,et al.  DETECTING THE THRESHOLD OF ANAEROBIC METABOLISM IN CARDIAC PATIENTS DURING EXERCISE. , 1964, The American journal of cardiology.