Coronary Arteries : Mnemonic

Right coronary artery (RCA)

Course:

1. Origin: Anterior aortic sinus (right cusp) of ascending aorta
2. Between right auricle and pulmonary trunk root
3. Right anterior coronary (atrioventricular) sulcus
4. Winds round the inferior border of heart
5. Right posterior coronary sulcus
6. Posterior interventricular groove
7. 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:

1. Origin: Left posterior aortic sinus of ascending aorta
2. Between pulmonary trunk and the left auricle
3. 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
4. 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