Cardiac Ischemia Model for +Gz Using Miniature Swine and Baboons
Abstract
Military aircrew with minimal coronary artery disease (MCAD) may be restricted from flying high-performance aircraft due to possible ischemia during high 1 Gz . An animal model is presented to provide ischemia data for a more informed decision. There were 18 swine that were placed on a high cholesterol/high fat diet for up to 57 wk. Five control swine were maintained on a standard swine diet. Also, nine male baboons had a constrictor placed around the left anterior descending coronary artery. Two baboons were sham-operated controls. The unanesthetized swine and baboons were infused with Tc-99m at the end of 1 Gz exposure and scanned for myocardial perfusion. Five swine died unexpectedly before 1 Gz exposure with moderate-to-severe CAD. Dysrhythmias during 1 Gz were seen equally in both the control and experimental swine and in the baboons before and after stenosis, with or without propranolol. During 1 Gz, ECG ST-T wave changes suggesting ischemia were observed in the cholesterol swine but not the control swine, and in the baboons before and after stenosis, with or without propranolol. There was a positive relationship between a normal/abnormal ECG and a normal/abnormal myocardial perfusion scan in the swine and a weak relationship in the baboon before stenosis, but somewhat better after stenosis. Coronary histopathology showed normal vessels from the control swine and stenoses ranging from 0-95% from the cholesterol swine. Baboon stenosis averaged 37.6 +/- 15.0%. In the swine and the baboon extended high levels of 1 Gz were associated with evidence of myocardial ischemia.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2008
- Accession Number
- ADA519728
Entities
People
- Edward J. Dick Jr.
- Harold Davis
- John W. Burns
- John W. Fanton
- Joseph Deering
- Londe A. Richardson
- Paul V. Celio
- Thomas H. Loecker
- William B. Kruyer
Organizations
- Air Force Research Laboratory