Right coronary artery anatomical variants: where and how?

Background. Ectopic origin of the right coronary artery (RCA) occurs in approximate to 1.0% of studied populations. We investigated the prevalence and location of ectopic RCAs among patients undergoing coronary angiography (CA) and assessed its effects on resource utilization. Methods. Cases of ectopic RCAs were prospectively collected over 21 months among patients undergoing cardiac catheterization at a University Hospital. "Ectopic RCA" was defined as a RCA originating outside the posterior two-thirds of the right coronary sinus. Results. The study population included 2,120 patients, of which 23 (1.1%) had ectopic RCAs. Of these, 15 (65%) originated from the anterior third of the right sinus, while 8 (35%) originated from the anterior half of the left sinus. Mean procedure and fluoroscopy times were 60 +/- 33 and 15 +/- 12 minutes (min) for the former, and 78 +/- 35 and 31 +/- 20 min for the latter, while mean contrast volume for CA was 112 +/- 62 ml and 192 +/- 85 ml, respectively. 26% required a second CA or a second intervention to image the RCA. Conclusion. Ectopic RCAs pose a clinical problem, consuming time and resources. The search for an ectopic RCA should have < 90 degree boundaries limited to the anterior third of the right sinus and anterior half of the left sinus.