In this review, I’m going to cover the anatomy of the coronary arteries.
The role of the coronary arteries is to supply the heart muscle, or myocardium, with fresh, oxygenated blood, allowing the heart muscle to continue pumping blood throughout the body.
There are two main coronary arteries to remember: the right coronary artery and the left coronary artery. These coronary arteries go to the right and left sides of the heart and branch off into smaller arteries to supply the myocardium.
Right Coronary Artery
First, let’s discuss the right coronary artery. Above is an anterior view, or front view, of the heart. The right coronary artery comes off the ascending aorta, which is part of the heart’s blood flow sequence, taking fresh, oxygenated blood from the left side and distributing it throughout the body.
The right coronary artery primarily supplies the right side of the heart and branches into smaller arteries. One of these is the sinoatrial node artery, which supplies the SA node in most people. The SA node is the first part of the electrical conduction system, creating the P wave in the ECG waveform.
Further along, the atrial branch supplies the right and left atria. Nearby, the right conus artery supplies parts of the right ventricle. As we continue down the right coronary artery, it branches off into the right anterior ventricular branch, supplying the right ventricle. It then splits into the right marginal artery, supplying the right ventricle and reaching the heart’s apex.
The right coronary artery eventually turns into the posterior descending artery, also called the posterior interventricular artery. This artery supplies the right and left ventricles, the interventricular septum, and sometimes the AV node.
Anatomy can vary, with most people having a right-dominant heart, where the posterior descending artery comes off the right coronary artery. In some, it comes off the left coronary artery, indicating a left-dominant heart.
Left Coronary Artery
Now, let’s look at the left coronary artery. Still viewing the anterior side, the left coronary artery also comes off the ascending aorta and splits into two main branches. One is the circumflex artery, which wraps around to the posterior side, supplying the left atrium and some of the left ventricle. Its branches, known as the left marginal or obtuse branches, supply the left ventricle and extend to the apex.
On the anterior side, the left coronary artery also branches into the left anterior descending artery, or LAD, sometimes called the anterior interventricular artery. This artery is crucial, supplying the interventricular septum, the left ventricle, parts of the right ventricle, and the bundle branches of the conduction system. A blockage here, known as the “Widow Maker,” can severely damage heart function.
The LAD also gives off diagonal branches that supply the left ventricle, and septal branches that supply the interventricular septum and the bundle of His.
Coronary arteries are crucial for heart health because they supply blood to the heart muscle. It is vital to prevent any blockages that could restrict blood flow to the myocardium, as this could result in a myocardial infarction. Understanding the anatomy and function of these arteries is essential. In my previous video, I discussed various types of angina and their treatments, which you might find helpful if you are studying this subject.
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References:
Coronary Arteries and Cardiac Veins, Editor(s): Michael P. Federle, Melissa L. Rosado-de-Christenson, Siva P. Raman, Brett W. Carter, Paula J. Woodward, Akram M. Shaaban, Imaging Anatomy: Chest, Abdomen, Pelvis (Second Edition), Elsevier, 2017, Pages 380-401, ISBN 9780323477819 https://doi.org/10.1016/B978-0-323-47781-9.50021-0.
Izhar M, El-Feky M, Bell D, et al. Right coronary artery. Reference article, Radiopaedia.org (Accessed on 16 Jan 2024) https://doi.org/10.53347/rID-8864
Marieb, E. N., & Mallatt, J. (2001). Chapter 18 The Heart. In Human Anatomy (Third, pp. 534–535).
Ogobuiro I, Wehrle CJ, Tuma F. Anatomy, Thorax, Heart Coronary Arteries. [Updated 2023 Jul 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK534790/