PDA (Posterior Descending Artery) & Coronary Dominance-A MDCT Coronary Angiographic Analysis of Anatomic Variations and Clinical Importance

PDA & Coronary Dominance

Abstract

Introduction: There is considerable variation in the arterial supply of diaphragmatic surface of the heart. Diaphragmatic myocardial infarction is one of the more common consequences of coronary artery disease. The aim of this study was to assess the incidence of anatomic variants of origin and termination of Posterior Descending Artery (PDA) and to determine the type of coronary dominance in North Indian population. Subjects and Methods: This prospective study was carried out on 50 routine subjects of different age groups who came to the Department of Radiodiagnosis, King Georges Medical University UP, Lucknow in the year 2010- 2011 with known or suspected coronary artery disease. All the cases were investigated on a 64 slice Multidetector Computed Tomographic (MDCT) scanner, using retrospective Electrocardiographic gating. Endeavour was made to determine the incidence of sites of origin and termination of PDA as well as to determine the type of coronary dominance. Results: PDA arose from Right Coronary Artery (RCA) in 39 (78%) cases and from Left Circumflex (LCx) artery in 11(22%) cases. The PDA was found to terminate in the upper 1/4 of Posterior Inter-Ventricular Groove (PIVG) in 18 (36%) cases, in upper 1/2 of PIVG in 19 (38%) cases, in upper 3/4 of PIVG in 10 (20%) cases and at the apex of the heart in 1 (2%) case. None of the female had termination of PDA at the apex. Termination of PDA could not be determined in 2 (4%) cases. Right dominance was seen in 36 (72%) cases, Left dominance in 11 (22%) cases. and Co-dominance in 3 (6%) cases. Conclusion: Posterior descending artery most commonly terminated after traversing the upper half of posterior inter-ventricular groove. The incidence of left coronary dominance was more in females, it was approximately twice the incidence found in males. Co-dominance was observed only in male subjects.