1. In the name of GOD ANATOMY AND PHYSIOLOGY OF THE HEART By Dr A.R Hoghooghi

2. GROSS ANATOMY Heart composed of 4 chamber,2 atria 2 ventricle form 2 separete pump arranged side by side and in serie. atria low pressure,capacitance chamber store blood during systole and fill vent during diastole 2 atria separate with thin IAS Ventricles are high pressure,pumping blood to lung and peripheral.LV IS THICKER. Separet with IVS memberanous in sup and thick muscular in medial and distal

3. Mitral valave and tricuspid Separate atrioventricular valaves Chorda tendinea attach valaves to papillary muscles Papillary muscle extension of normal myocardium Seminular valves AOV and PV do not have chorda fibrous valves Each valves has fibrous ring or annulus

4. Pericardium Double layered,surround heart Visceral pericardium is adherent to heart Parietal attaches to sternum,vertebral column,diaphragm serves to to stabilize heart Pericardium has 50 ml fluid which is normal Pericardial fluid lubricate contact surface and modulates interventricular interaction

5. CIRCULATORY PATHWAY 2 DISTINCT PARALLEL VASCULAR NETWORK ARTERIAL VENOUS DEOXYGENATED BLOOD FROM TISSUES DRAIN FROM SUP AND INF VENA CAVA TO RIGHT ATRIUM BLOOD FROM HEART DRAINS FROM COROARY SINUS TO RIGHT ATRIUM OXYGENATED BLOOD DRAINS FROM LUNGS TO PULMONARY VEIN (4) HEART RECIEVES BLOOD FROM RIGHT AND LEFT CORONARY ARTERIES

6. CORONARY ARTERIES They are first braches of aorta Originating from sinuses of valsalva Left main coronary arteries originates in left sinus of valsalva which biforcate to 2 vessel left circumflex(lcx) and (LAD) LAD travel anterior interventricular groove toward apex LAD suplies blood for ant and anterolat LV by septal branches through its DIAGONAL branches and to ant of 2/3 intventricular septum

7. LCX TRAVELES POSTERIORLY IN THE LEFT AVGROOVE,suplies blood for lat LV through optus marginal branches and also LA

8. RCA RCA is originate from right sinus of valsalva Courses down the right AV groove to a point wher the left and right AV groove and inferior interventicular groove meet,the crux of the heart Gives off atrial branch and acute marginalis branches for RV In 85% RCA biforcate at crux to pda travels infinterventricular groove to supply blood to the inf lv wall and inf 1/3 of interventricular septum and plv supply blood for post lvwhich is right dominant.10% left dominant and PDA PLV from lcx,5%codominant RCA gives PDA and LCX gives PLV

9. COLLATERALS Nonfunctional in normal heart because no pressure gradient developes accros them Developing of collaterals is directly dependet to severity coronary stenosis,can reach to 1mm diameter

10. Conduction system SA node, pacemaker cells,1 to 2 cm diameter,located high in RA between SVC RA appendag,supply by sa nodal artery 60% from RCA and 40% from LCX AV node located in at inferior aspect of RA between coronary sinus and septal leaflet of tricuspid valveprovide normal electricalconnection between atria ventricles,Avnodal branch 90% RCA 10% lcx

11. Bundle of His extend from av to membrabous IVS to muscular part of IVS SEPARATE TO 2 BRANCHES RIGHT BUNDLE is disceret branch extend along IVS enter moderator band and to anterolateral papillary muscle of RV,blood from septal perforator lad LBB IS LESS DISTINCT ant fascicle to anterolat papilary muscle and post fascicle to posterolatral papillary muscle of lv,blood for ant fascicle by septal perforator lad, susceptable to ischemia,blood for post (proximal from av node artery and septal and distal from lad and pda

12. Neural innervation Sympathic preganglionic neurons located within sup five to six thoracic segment These fibers end in the SA node AV node,epicardial vessel and myocardium Parasympathetic from preganglionic neurons originating in the dorsal motor nucleus of the medulla and pass as a branch fo vagus nerve to heart Supply of vagal afferent from the inferior and posterior aspects of the ventricle mediate cardiac reflexes

13. Circulatory physiology and the cardiac cycle During the course of one cardiac cycle,the electrical event initiate and therefore precede the mechanical (pressure )events,and the latter precedes the ausculatory events (heart sounds)they themselvesw produce.shortly after the p wave the atria contract to produce a wave.the QRS complex initiate ventricular systole,followed shortly by lv contraction and rapid buildup of LV pressure.lv pressure exceeds LA pressure,closing the mitral valave and producing the first heart sound after a period of isovolumic contraction,lv pressure exceeds aortic pressure and AV OPENSwhen the ventricular pressure once again falls below the aortic pressure,and the aortic valve close to produce the second heart sound and terminate ventricular ejection.the lv pressure decreasee during the period of isovolumic relaxation until it drops below LA pressure,and the mitral valve opens

14. Cardiac performance The amopunt of blood ejected by the each minute is refered to as the cardiac output is the product of stoke volume and HR CARDIAC INDEX :co divided by BSA NORMAL CO:4 TO 6 LIT /MIN can increase during exercise 4 to 6 fold as a result of hr chronotropy or sv inotropy

15. Sv is a measure of mechanical function of the heart and is affected by preload afterload and contractility Preload is the volume of blood in the ventricle at the end of diastole and is primarily a reflection of venous return,(ventricular filling pressure, atrial pressure or pcwp)used as a surrogate measure of preload Afterload is the force against which the ventricle must contract to eject blood.the arteria pressure as a practical measure of after load,as atruth the interventricular pressure the size of vent cavity and thickness of ventricular wall (laplace s law)determine after load so in hypertension stenosis and lvh and lv dilation is increased afterload

16. Ejection fraction Overall ventricular systolic function is frequently quantified by the ejection fraction Which is the ratio of the sv to the end diastolic volume that is fraction of blood in the ventricle ejected with each ventricular contraction Normal ef is about 60% Ventricular diastolic function (lusitropy)also plays an important role in over all cardiac performance

17. Myocardial oxygen consumption mvo2 the main determinant are HR contractility and wall stress which is determined by laplace law =(pressure*radius)/(2*wall thickness) Most coronary flow occurs during diastole therefore diastolic pressure is the major pressure driving the coronary circulation