The Effects of Carbon Monoxide on Coronary Hemodynamics and Left Ventricular Function in the Conscious Dog,
Abstract
Low levels of carboxyhemoglobin can cause significant changes in coronary blood flow. Hypoxia induced by the elevation of COHb appears to have a different effect on the cardiovascular system than hypoxia induced by lowering the inspired oxygen. If the inspired O2 is lowered, the arterial Po2 is decreased. Under this condition,, an increase is observed in coronary flow, heart rate, coronary stroke volume, and left ventricular dP/dt. When the inspired oxygen is held constant and the COHb is elevated, there is no change in the arterial Po2. An increase is observed in coronary flow, heart rate and coronary stroke volume but no changes in left ventricular dP/dt occur. The difference between the two modes of hypoxia is in the contractile force of the myocardium. The mechansim involved in the changes observed does not seem to be related to arterial Po2, since the carotid and aortic chemoreceptors are not known to be stimulated by increased concentrations of COHb. However, the heart rate increased with both modes of hypoxia, suggesting that the mechanism may involve central nervous system structures. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0727511
Entities
People
- Howard H. Erickson
- Hubert L. Stone
- Jim D. Adams
Organizations
- Air Force Research Laboratory