Right coronary artery (RCA)
Course:
- Origin: Anterior aortic sinus (right cusp) of ascending aorta
- Between right auricle and pulmonary trunk root
- Right anterior coronary (atrioventricular) sulcus
- Winds round the inferior border of heart
- Right posterior coronary sulcus
- Posterior interventricular groove
- Anastomose with left coronary artery
Branches:
Mnemonic: TRaP Me IN
Large:
- Marginal (largest branch)
- Accompanied by Small cardiac vein
- Supplies: Right ventricle
- Posterior Interventricular (Posterior Descending Artery/PDA)
- Accompanied by Middle cardiac vein
- Supplies: Diaphragmatic surface of both ventricles, Septal branch of AVN, Posterior part of interventricular septum
- Cardiac dominance: In 65% cases, PDA arise from RCA (right dominance) and in other cases from LCA (left dominance)
- misleading term: because LCA always supplies greater myocardial portion
Small:
- Nodal: Supplies SAN and both atria
- Right atrial
- Infundibular
- Terminal
Left coronary artery (LCA)
Course:
- Origin: Left posterior aortic sinus of ascending aorta
- Between pulmonary trunk and the left auricle
- Anterior interventricular groove
- Anterior interventricular artery: to apex of heart
- Circumflex artery (LCA): left anterior coronary sulcus → winds round left margin of heart → left posterior coronary sulcus → Supplies posterolateral wall of left ventricle
- Anastomose with right coronary artery
Branches:
Mnemonic: LaTe PAD
Large: Left Anterior Descending (LAD) artery –
- Anterior Interventricular
- Accompanied by Great cardiac vein
- Supplies: Anterior 2/3 of interventricular septum
- Diagonal branch
- Supplies: Lateral wall of left ventricle
Small:
- Left atrial
- Pulmonary conus
- Terminal
Arterial supply of conducting system of heart
1. RCA: SA node, AV node, AV bundle
2. LCA: Right bundle branch of AV bundle
3. Both RCA and LCA: Left bundle branch of AV bundle
Division of Coronary arteries
Coronary arteries → Epicardiac arteries → Final/intramural vessles