WORK PERFORMANCE OF A RAT HEART-LUNG PREPARATION: STANDARDIZATION AND INFLUENCE OF CORTICOSTEROIDS1,2

Abstract

Experimental conditions have been established for the operation of a rat heart-lung preparation which result in a high degree of uniformity of work performance as measured by left ventricular work index (LVWI) (proportional to the product of cardiac output and mean arterial blood pressure). At a perfusion blood temperature of 37[degree] C heart rate was higher and left ventricular work index lower than at 32[degree] C. Peripheral resistance was adjusted to give an analysis of the work performance of the heart-lung at three different levels of mean arterial blood pressure: 80, 110, and 130 mm. Hg. The lower the pressure, the greater LVWI. Heart rate was not influenced by alterations in peripheral resistance.