Coronary artery dominance

# Overview
The dominance of coronary circulation is determined by the type of arteries that supply the posterior and inferior wall of the left ventricle.  The artery that supplies the posterior descending artery (PDA) and the posterolateral artery (PLA) determines the coronary dominance.  Approximately 60% of the general population are right-dominant, 25% are co-dominant, and 15% are left-dominant.

# Coronary Artery Dominance
The coronary artery dominance describes how many of the three major branches supplying the posterior and inferior wall of the left ventricle from the right coronary artery (RCA) and how many arise from the circumflex artery (CX).  In order to determine the anatomic dominance, the three inferior wall vessels must be specified.  There are four types of coronary tree dominance: large right dominant, small right dominant, co-dominant and left dominant.

## Large Right Dominance
Shown below is an image depicting a large right dominant coronary artery.  A right coronary artery is said to have a "large" dominance when 3 branches arise beyond the distal bifurcation of the right coronary artery (RCA) to supply the septum and the infero-posterior walls. These 3 branches are as follows:
- The right posterior descending artery (RD or RPDA) supplies the inferior septum.
- A branch off of the right posterolateral artery (the right posterolateral artery, RPL or R4 between the two hatched lines) called the right inferior branch (RI) supplies the infero-posterior wall.
- A branch off of the right posterolateral artery (the right posterolateral artery, RPL or R4 between the two hatched lines) called the right posterior (RP) supplies the infero-posterior wall.
CX= Circumflex artery; LAD=Left anterior descending artery; R4= Right posterolateral artery; RCA= Right coronary artery; RD= Right posterior descending artery;  RI= Right inferior artery ; RP= Right posterior artery; RPDA= Right posterior descending artery; RPL= Right posterolateral artery.  For a full description of the labels, please see the table at bottom of the page.

## Small Right Dominance
Shown below is an image depicting a small right dominant coronary artery.  A right coronary artery is said to have a "small" dominance when 2 branches arise beyond the distal bifurcation of the right coronary artery to supply the septum and the posterior wall. These 2 branches are as follows:
- The right posterior descending artery (RD or RPDA) supplies the inferior septum.
- A branch off of the right posterolateral artery (the right posterolateral artery, RPL or R4 between the two hatched lines) called the right inferior branch (RI) supplies the infero-posterior wall.
The circumflex posterior artery (CP) arises from the circumflex artery (CX) and supplies the inferior wall.
CP= Circumflex posterior artery; CX= Circumflex artery; LAD=Left anterior descending artery; R4= Right posterolateral artery; RCA= Right coronary artery; RD= Right posterior descending artery;  RI= Right inferior artery ; RPDA= Right posterior descending artery; RPL= Right posterolateral artery.  For a full description of the labels, please see the table at bottom of the page.

## Co-Dominance
Shown below is an image depicting co-dominant coronary artery. A coronary artery is said to have a "co-dominance" or balanced dominance when only the right posterior descending artery (RD or RPDA) arises from the right coronary artery (RCA), while the circumflex inferior artery (CI) and the circumflex posterior artery (CP) arise from the circumflex artery (CX).
C4= Left posterolateral artery; CI= Circumflex inferior artery; CP= Circumflex posterior artery; CX= Circumflex artery; LAD=Left anterior descending artery; LPL= Left posterolateral artery; RCA= Right coronary artery; RD= Right posterior descending artery; RPDA= Right posterior descending artery. For a full description of the labels, please see the table at bottom of the page.

## Left Dominance
Shown below is an image depicting left dominant coronary artery. A coronary artery is said to have "left" dominance when the left posterior descending artery (CD or LPDA), the circumflex inferior artery (CI)  and the circumflex posterior (CP) artery all arise from the circumflex artery (CX).
C4= Left posterolateral artery; CD= Left posterior descending artery;  CI= Circumflex inferior artery ; CP= Circumflex posterior artery; CX= Circumflex artery; LAD=Left anterior descending artery; LPL= Left posterolateral artery; RCA= Right coronary artery; LPDA= Left posterior descending artery.  For a full description of the labels, please see the table at bottom of the page.
Shown below is a table listing all the segments of the RCA and LCA in terms of corresponding numbers, labels, locations and anatomic descriptions.

# Coronary Angiography of the Coronary Artery Dominance