The coronary collateral circulation: Determinants and functional significance in ischemic heart disease

Abstract

Richard Lower is given credit for having first postulated the existence of coronary collaterals or coronary interarterial anastomoses in 1869. Long after, the work of Spalteholz (1907), Gross (1921), James (1961), and Fulton (1965) combined to confirm their existence.’ Since then, a great deal has been thought, spoken, and published about coronary collaterals, but significantly less has been incontrovertibly demonstrated or proven. This presentation considers what is currently known and what is postulated with respect to the coronary collateral circulation. The specific questions addressed include: (1) the mode of growth and development and the anatomic distribution of coronary collaterals (when and where they are present and absent); (2) the role of physical exercise in the development of coronary collateralization; (3) functional efficacy of coronary collaterals (with respect to relief of myocardial ischemia, frequency of left ventricular (LV) dysfunction, myocardial infarction (MI), cardiac arrhythmias, and both sudden and nonsudden coronary death; (4) the relationship between nature’s coronary bypasses (collaterals) and man-made coronary bypasses (surgical grafts)-which are more effective? Do the former obviate the latter? What is the fate of the former following placement of the latter? and; (5) the question of our ability to pharmacologically or mechanically influence the function of coronary collaterals.