Much of the basic experimental work which made the recent advances in the treatment of heart disease possible was done on one or another of the various preparations for isolating the heart and lungs. The study of any individual organ is facilitated by its isolation from the other organs in the body. In the investigation of the heart, it was found that the mammalian heart did not lend itself to isolation as did the heart of the frog and the turtle.
The problem of getting the isolated mammalian heart to perform work pumping blood and not just to beat has intrigued many prominent physiologists. Although the heart continues to beat as long as its coronary arteries are perfused, its energetics, metabolism, and other vital functions cannot be evaluated unless it is performing work. The qualitative and quantitative analysis of undiluted coronary blood is difficult because the collection of such blood
ALLANSMITH R, MATHEWSON CW. A New Preparation for Study of the Completely Isolated Mammalian Heart and Lungs. AMA Arch Surg. 1960;80(5):822-829. doi:10.1001/archsurg.1960.01290220114013