Metabolic Assessment of Internal Mammary Artery Implantation in the Dog
The metabolic and physiologic contributions of an implanted internal mammary artery have been assessed in five dogs 24 to 34 months following internal mammary artery implantation and concomitant ameroid constrictor application to coronary arteries. All implants were patent angiographically prior to evaluation by right heart bypass and continual autoanalyzer assessment of myocardial oxygen, pyruvate, and lactate extraction. Control internal mammary artery flow averaged 17.5 ml/100 g LV/min. Occlusion of the internal mammary artery failed significantly to alter myocardial extraction of oxygen, pyruvate and lactate or ventricular function, nor did these patent implants prevent significant changes in oxygen, pyruvate, and lactate extraction and ventricular function during and following occlusion of a remaining patent left coronary artery. In only one animal did internal mammary artery flow increase with left coronary artery occlusion, and this only transiently. These results indicate that demonstration of angiographic patency of an internal mammary artery implant does not necessarily indicate significant metabolic or functional contribution of this extracardiac blood supply to the heart.
- © 1970 American Heart Association, Inc.