Cardiac Path Online
Normal Anatomy - Coronary Arteries of the Heart
The coronary arteries are the first branches of the aorta and usually, arise within the aortic sinuses of Valsalva.
There are two arteries, right and left, but three sinuses.
This permits the normal sinuses to be distinguished as right coronary, left coronary and non-coronary.
The right coronary artery emerges from the sinus directly into the antero-superior part of the right arterioventricular groove.
It then encircles the tricuspid valvar orifice, giving rise to ventricular and atrial branches.
In nine-tenths of individuals, it gives rise to the posterior interventricular artery and in most continues beyond the crux to supply part of the diaphragmatic surface of the left ventricle (right coronary dominance).
The left coronary artery emerges from its sinus into the space between the pulmonary trunk and the left atrial appendage.
After a short course, usually of no more than one centimeter, the left coronary artery divides into anterior interventricular (descending) and circumflex branches.
The anterior artery runs down the interventricular groove, giving perforating branches to the septum, infundibular branches to the right ventricle, and diagonal branches to the left ventricle.
The circumflex artery runs round the mitral orifice, usually with a short course and gives obtuse ventricular and atrial branches.
Sometimes the first obtuse branch arises as a third artery directly from the left main stem.
In one-tenth of individuals, it is the circumflex artery which gives rise to the posterior interventricular artery (left coronary dominance).
The areas of heart supplied by the three coronary arteries are as follows:
1. Left anterior descending branch : Supplies anterior wall of left ventricle and adjacent area of anterior right ventricle and anterior two-thirds of the interventricular septum (accept the apical region).
2. Left circumflex branch : Supplies lateral wall of the left ventricle.
3. Right coronary artery : Supplies remainder of the right ventricle, posterior region of left ventricle and posterior third of the interventricular septum. Image Link
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