VARIATIONS IN THE ORIGIN AND COURSE OF THE POSTERIOR INTERVENTRICULARARTERY IN RELATION TO THE CRUX CORDIS AND THE POSTERIOR INTERVENTRICULAR VEIN - AN ANATOMICAL STUDY

Corrosion castings of 60 human hearts were used to demonstrate that th e point of origin of the posterior interventricular artery (PIA), in r elation to the crux cordis, is responsible for its subsequent course w ith respect to the posterior interventricular vein (PTV). In seven cas es (12%), the PIA appeared as the continuation of the left circumflex, descending rightwards and on a deeper level of the PTV. In 53 cases ( 88%), the PIA arose from the right coronary artery (RCA) and 50 of the se were selected to be classified into three groups, according to the PIAs origin and course. In group A (29 cases, 58%) and B (seven cases, 14%), the PIA emerged before the crux cordis and descended to the rig ht or left of the PN, respectively. In group C (14 cases, 28%), it ori ginated at, or beyond, the crux cordis and descended along the left si de of the PTV. Among the 50 cases, the PIA was found to be long in 34 (68%), large in 32 (64%), and long and large in 29 cases (58%). In 18 of the latter 29 cases (62%) or 36% of the 50 cases in total, the PIA arose as a continuation of the RCA (group A) and therefore these cases were easily accessible to interventional cardiologists and also to su rgeons, since the PIA lay on the same or on a superficial level in rel ation to the PTV. This work describes and explains the variations of t he PIA and concludes that at least 36% of these may be helpful in coro nary artery angioplasty and bypass surgery. Anat. Rec. 252:413-417, 19 98. (C) 1998 Wiley-Liss, Inc.