Posterior interventricular artery
The posterior interventricular artery (posterior descending artery, PDA) is a branch of the right coronary artery. It is also commonly referred to as the inferior interventricular artery, a more accurate name given that it is not located on the posterior surface of the heart. Instead, it runs along the inferior (diaphragmatic) surface, within the inferior interventricular sulcus. Its main function is to supply the diaphragmatic (inferior) surface of the myocardium and interventricular sulcus of the heart.
The inferior interventricular artery can arise from either the left or right coronary artery. The "dominant" coronary artery is the one that gives rise to inferior interventricular artery. In the majority of the population, the right system is dominant, meaning that this irrigates the heart’s diaphragmatic (inferior) surface.
This article will discuss the anatomy and function of the posterior interventricular artery, more accurately referred to as the inferior interventricular artery.
Origin | Right coronary artery (65% of people) |
Branches | Perforating interventricular septal branches |
Supply | Diaphragmatic surface of the heart |
Origin and course
In most cases, the inferior interventricular artery originates from the right coronary artery. It arises on the diaphragmatic aspect of the heart when the right coronary artery approaches the crux of the heart. The crux of the heart is the meeting point of the interatrial and interventricular septa of the cardiac chambers. The inferior interventricular artery descends in the interventricular sulcus towards the apex of the heart. When it reaches the apex it anastomoses with the anterior interventricular artery, a branch of the left coronary artery.
The term "dominance" of either side of the coronary arterial circulation is determined by which artery gives rise to the inferior interventricular artery and supplies the diaphragmatic surface of the heart. The right coronary is dominant in approximately 65% of the population. It's important to keep in mind that the term "dominant" is potentially misleading since it can be interpreted as the vessel which irrigates the greater portion of the myocardium. However, it is always the left coronary artery that supplies the greater myocardial portion.
Branches and supply
The inferior interventricular artery supplies the diaphragmatic (inferior) aspect of the myocardium. On its course in the inferior interventricular septum, the inferior interventricular artery gives off several perforating interventricular septal branches. These branches supply the inferior aspect of the left and right ventricular walls.
Learn more about the coronary arteries with our articles, videos, labeled diagrams and quizzes.
Anatomical variations
- The inferior interventricular artery can originate from either the right coronary artery or from the circumflex artery, a branch of the left coronary artery. In some cases, there can be two inferior interventricular arteries that arise from both the right coronary artery and the circumflex artery.
- Functionally, the inferior interventricular artery can be a terminal or a collateral branch, depending on the anastomoses that this artery forms with the anterior interventricular artery.
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