title: An experimental model for studying myocardial ischemia. Correlation of hemodynamic performance and metabolism in the working swine heart.
abstract: 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.
mesh_terms: 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
chemical_list: D007773:Lactates