Postsystolic myocardial augmentation has been shown to decrease left ventricular work and improve coronary blood flow experimentally.1,2 Increase in coronary blood flow has more frequently been demonstrated during postsystolic augmentation in animals with myocardial ischemia.3-5 Other investigations have failed to demonstrate measurable or appreciable increases in coronary flow in normal animals despite changes in phasic coronary blood flow pattern.6
Postsystolic myocardial augmentation with the army artificial heart pump consistently decreased aortic systolic pressure, aortic end diastolic pressure, left ventricular pressure, and left ventricular work in dogs.7 Aortic diastolic pressure was consistently augmented and coronary blood flow usually increased.
Postsystolic augmentation has not been previously studied in subhuman primates, whose physiological response should be more consistent with the expected results in man. This study was done to evaluate the response of the baboon to postsystolic augmentation with the army artificial heart pump.
Materials and Methods