Coronary Circulation Lecture Notes PDF

Coronary circulation: ◦Supply of blood to the myocardium ◦Coronary circulation begins at the base of the aorta ‣ Splits into two branches: There is a right and left coronary artery ‣ Coronary vessels get filled with blood during diastole (relaxation)...

Coronary circulation: ◦Supply of blood to the myocardium ◦Coronary circulation begins at the base of the aorta ‣ Splits into two branches: There is a right and left coronary artery ‣ Coronary vessels get filled with blood during diastole (relaxation) ‣ Right and left coronary arteries have three main branches Coronary arteries: ◦End arteries: do not have sufficient overlap or anastomoses Right coronary artery (RCA): ◦Supplies right atrium and right ventricle ◦Arises from right cusp of aortic valve ◦Flows along the coronary sulcus SA nodal artery (RCA): ◦Arises from right coronary artery ◦Supplies the SA node Right marginal artery (RCA): ◦Supplies right ventricle and apex ◦Also known as acute marginal artery Posterior descending artery (PDA) - RCA: ◦Supplies right and left ventricles and interventricular septum ◦Also known as the posterior interventricular artery  Dominance: ◦Defined by which artery gives rise to the PDA Right Left codominance ◦Right dominance ~70-80% ◦Left dominance ~10% ◦Co-dominant ~5.7% Left coronary artery (LCA): ◦Arises from the left cusp of aortic valve ◦Flows along the coronary sulcus Left anterior descending artery (LAD) - LCA: ◦Supplies right and left ventricles and interventricular septum ◦Also known as anterior interventricular artery ◦Also known as the widow maker Left circumflex artery (LCX) - LCA: ◦Arise from the left coronary artery ◦Supplies left atrium and left ventricle Left marginal artery - LCA: ◦Also known as obtuse marginal artery ◦Supplies left ventricle Coronary arteries: recap: Cardiac veins: ◦All veins drain to coronary sinus -> right atrium Great cardiac vein: ◦Drains the same cardiac territory supplied by the LCA (LAD, marginal and circumflex arteries)  Middle cardiac vein: ◦Posterior surface of interventricular septum drains the PDA Small cardiac vein: ◦Right margin of heart and drains SA nodal and right marginal arteries Coronary sinus: ◦Small cardiac, middle cardiac and great cardiac veins all drain into the coronary sinus. ◦Coronary sinus then drains into the right atrium. End arteries: ◦No other anastomoses from other arteries ◦There are two types of end arteries: ‣ Functional end arteries - 1 main artery with smaller branches to supply an organ. If you cut off the supply from the main organ, the smaller branches aren’t enough to supply that organ. ‣ True end arteries - only 1 artery supplying that organ Difference between ischemia and infarction: ◦Ischemia - reduced oxygen ◦Infarction - cell death