How to Recognize Type of Coronary Dominance.

There are three types of coronary dominance. It depends on what coronary artery supplies the posterior descending artery. It can be estimated angiographically. First, have a look at the coronary anatomy. Posterior descending artery is written in red color.

• "RIGHT-DOMINANT" (70% of population): posterior descending artery is supplied by the right coronary artery;

• "LEFT-DOMINANT" (10% of population): posterior descending artery is supplied by the circumflex artery, a branch of the left artery;

• "CO-DOMINANT" (20% of population):  posterior descending artery is supplied by both the right coronary artery and the circumflex artery.

      Dominance has important implications in myocardial ischaemia and infarction.

      The tissue separating the right and left ventricles of your heart (the interventricular septum) receives blood predominantly from the left coronary artery, but the exact breakdown of blood source is determined by each heart’s specific organization of coronary artery branches. In right and co-dominant hearts, this septum receives blood from the left and right coronary arteries. If the left coronary artery is blocked, collateral circulation can develop via the also-contributing right coronary artery. In left-dominant hearts, this septum receives blood from only the left coronary artery. If the left coronary artery is blocked, there’s no chance of collateral flow developing and this blockage will cause a heart attack.

      A precise definition of dominance would be the artery which gives off supply to the AV node i.e. the AV nodal artery. Most of the time this is the right coronary artery.

more on headingfortheexits.com, wikipedia.org