An experimental model for studying myocardial ischemia. Correlation of hemodynamic performance and metabolism in the working swine heart.
An intact, working swine heart preparation with controlled coronary perfusion is described. In this model, hemodynamic and metabolic functions were correlated in control and ischemic myocardium. A closed-loop, extracorporeal coronary perfusion circuit in series with a perfusion pump and oxygenator was designed to return reoxygenated coronary venous blood at controlled flow rates to the left and right coronary arteries. In 9 swine at normal flows (232 plus or minus 17 ml. per minute), the preparation maintained stable hemodynamic performance and oxygen consumption for a 1 hour period, after which ischemia was induced by reducing coronary flow by 50 per cent. As a result, left ventricular end-diastolic pressure (LVEDP) rose by 227 per cent, whereas heart rate (-17 per cent), aortic pressure (-9 per cent), pressure time/minute (PTM) (-28 per cent), left ventricular work (-47 per cent), and oxygen consumption (-39 per cent) all decreased. The ischemic myocardium shifted from lactate extraction to production. With this model, we can define, over a period of time, several mechanical and metabolic collations as a function of total coronary blood flow in an intact, large animal. We can also test interventions during the acute phases of ischemia in an effort to reduce myocardial damage.
D000818:Animals; D001366:Axillary Artery / Q000601:surgery*; D001794:Blood Pressure; D003326:Coronary Circulation; D004195:Disease Models, Animal; D004209:Disposable Equipment; D005112:Extracorporeal Circulation; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D006439:Hemodynamics; D007773:Lactates / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D010106:Oxygenators; D013552:Swine
D007773:Lactates