Does gradual coronary narrowing produce functional intercoronary arterial anastomoses that protect the myocardium from acute occlusion in animal models?
Gradual coronary narrowing (75% for ≥12 days) stimulates the development of functional intercoronary collaterals that can protect the myocardium from subsequent acute complete occlusion in animal models.
Animal experiments were done to learn the degree of coronary narrowing required to produce the larger intercoronary collateral channels, their speed of development, and the degree of protection afforded the myocardium. Twelve or more days of 75 per cent narrowing were required to produce sufficiently rich anastomotic communications to protect the myocardium from damage, and to permit survival after superimposed acute complete occlusion. The physiologic and pathologic significance of the intercoronary collateral communications and the clinical implications in coronary artery disease are discussed.
Blumgart et al. (1950) studied this question.