Blood supply to heart

Coronary Circulation

1. BLOOD SUPPLY TO HEART By: Sathish Rajamani Associate Professor

2. Blood supply to the heart is also known as coronary circulation. It consist of ARTERIAL SUPPLY VENOUS DRAINAGE LYMPHATIC DRAINAGE

3. ARTERIAL SUPPLY

4. The heart receives its own supply of blood from the coronary arteries. Two major coronary arteries branch off from the aorta near the point where the aorta and the left ventricle meet. These arteries and their branches supply all parts of the heart muscle with blood.

5. RIGHT CORONARY ARTERY Smaller than left coronary artery. Arises from anterior coronary sinus Course: Emerges from the surface of the heart between pulmonary trunk and right auricle. Winds around the inferior border to reach the diaphragmatic surface to reach the posterior interior – ventricular groove. Terminates by anastomosing with left coronary artery.

6. Branches of the Right Coronary Artery Large Branches Marginal Post – Interventricular Small Branches Right arterial Infundibular Nodal Terminal

7. Areas of Distribution Right Atrium Ventricles Greater part of right ventricle. Small part of left ventricle . Posterior part of the inter – ventricular septum. Whole of the conducting system of the heart except a part of the left branch of AV bundle. The SA node is supplied by left – coronary artery in 40% cases.

8. LEFT CORONARY ARTERY Larger than the right coronary artery. Arise from left – posterior aortic sinus.

9. Course: Runs forward and to the left and emerges between the pulmonary trunk and the left auricle. Here the anterior inter-ventricular branch is given. The further continuation of the left coronary artery is sometimes called the circumflex artery. After giving off the anterior inter-ventricular branch it runs into the left anterior coronary sulcus. In winds around the left border and near posterior inter-ventricular groove . It terminates by anastomosing with the right coronary artery.

10. Branches: Large Branches: Anterior Interventricular Branch to the diaphragmatic surface of the left ventricle. Small Branches: Left Atrial Pulmonary Terminal

11. Areas of Distribution Left atrium Ventricles Greater part of the left ventricle, except the area adjoining the posterior inter-ventricular groove. A small part of the right ventricle adjoining the anterior inter-ventricular groove. Anterior part of the inter-ventricular septum. Part of left branch AV bundle.

12. COLLATERAL CIRCULATION Cardiac Anastomosis: the two coronary artery anastomose to the myocardium. Extra Cardiac Anastomosis: the cardiac arteries anastomosis with other organ’s arteries. Vasa Vasorum of the aorta Vasa Vasorum of the pulmonary arteries Internal thoracic arteries The bronchial arteries Phrenic arteries These channels open up in the emergencies when the coronary arteries are blocked.

13. CORONARY ARTERY DOMINANCE The artery that gives the posterior inter-ventricular artery determines the coronary dominance. RCA (Right Coronary Artery) CX (Circumflex Artery)

14. VENOUS DRAINAGE The venous drainage of the heart is by 3 ways A. Coronary Sinus Anterior Cardiac Veins Venae Cordis Minimae

15. Coronary Sinus – this is the largest vein of the heart situates in the left posterior coronary sulcus. It is about 3 cm long and ends by opening into the posterior wall of the right atrium. Its Branches are Great Cardiac Vein – it enter the left end of the coronary sinus. Middle Cardiac Vein – it accompanies the posterior inter-ventricular artery and joins the right end of the coronary sinus. Small Cardiac Veins – it accompanies the right coronary artery and joins the right end of the coronary sinus.

16. Posterior vein of Left Ventricle : it runs on the diaphragmatic surface of the left atrium and ends in the middle of the coronary sinus. Oblique vein of the left atrium – it runs on the posterior surface of the left atrium , joins the left end of coronary sinus and develops from the left common cardinal veins. The right marginal veins – it accompanies the marginal branch of the right coronary artery.

17. ANTERIOR CARDIAC VEINS – 3 – 4 small veins run on the anterior wall of the right ventricle, open directly into the right atrium. VENAE CORDIS MINIMAE Numerous small veins present in all 4 chambers of the heart which opens directly into the cavities. The thebesian venous network is considered as an alternative pathway for venous drainage of the myocardium.

18. LYMPHATIC NETWORK It accompanies the coronary artery and form 2 trunks. Rt trunk ends in bracheocephalic nodes and the left trunk into the tracheobronchial lymph nodes at the bifurcation of the trachea.

19. Applied Anatomy Angina Pectoris – Severe chest pain due to ischaemia of the heart. Angina pectoris is due to the narrowing of the arteries. Myocardial Infarction - it means necrosis of a part the myocardium due to severe prolonged ischaemia due to ischaemia of coronary arteriies . Occlusion of the one of the coronary arteries or its branches.