Collateral Circulation Following Experimental Gradual Narrowing of the Coronary Arteries

Abstract

Sudden and gradual occlusion of the right coronary artery 5 mm from its ostium in 49 pigs has been performed. The reasons for the survival of some of the animals in which gradual occlusion had been produced are discussed. It is concluded that the development of collateral channels was the most likely explanation for this occurrence. A preliminary study of a series of pigs treated with an oral long acting nitrate, before and after gradual occlusion with an artificial occluder 1.57 mm in diameter, showed a significantly increased number of survivals when compared with a similar group which received no drug.