1. Cardiovascular Structure & Function Cardiovascular Structure & Function

2. Cardiovascular system: The heart Arteries Veins Capillaries Lymphatic vessels

3. Weighting of the heart ceremony: Ancient Egyptians

4. William Harvey and Blood Flow April 1, 1578 – June 3, 1657

5. Introduction The most basic functions of the cardiovascular system are: To deliver oxygen and nutrients to body tissues To remove waste To regulate temperature

6. Circulatory system

7. 1. Left ventricle 2. Aorta 3. Arterial system 4. Vena cava 5. Right atrium 6. Right ventricle 7. Pulmonary artery 8. Lungs 9. Pulmonary veins 10. Left atrium 1. Left ventricle

8. Heart valves Pulmonary Aortic Mitral Tricuspid

9. Systolic and Diastolic phases Diastolic phase = Ventricular filling Systolic phase = Ventricular ejection

10. Cardiac cycle Systole Diastole Animation: http://library.med.utah.edu/kw/pharm/hyper_heart1.html

11. Aortic and Ventricular Pressures 0 50 100 80 120 160 Pressure (mmHg) LV volume (mL) Ejection PAPA P LV

12. Left Atrium2-11 Left ventricle90-140 / 5-12 Aorta90-140 / 60-90 Right Atrium0-8 Right ventricle15-30 / 0-8 Pulmonary artery15-30 / 4-12 Normal pressures Unit = mmHg [1 mmHg = 133 Pa]

13. Intra-cardiac and arterial pressures

14. Hypertension Hypertension is defined as an abnormal increase in arterial pressure Hypertension results in an increase in ventricular work and ventricular hypertrophy

15. Pressure and Flow 00.511.5 0 50 100 mmHg 00.511.5 0 200 400 time in s mL/s Systolic Pressure Diastolic Pressure

16. Systolic pressure = maximal pressure Diastolic pressure = minimal pressure CATEGORY SYSTOLIC (mmHg) DIASTOLIC (mmHg) Normal< 130< 85 Normal ++130-13985-89 Hypertension STAGE 1 (Mild)140-15990-99 STAGE 2 (Moderate)160-179100-109 STAGE 3 (Severe)180-209110-119 STAGE 4 (Very Severe)>209 >119 A very low pressure should also by examined by a Doctor. Classification of arterial pressure (> 18 years)

17. Ventricular pressure-volume curves 6080100120140160 0 20 40 60 80 100 120 00.20.40.60.8 0 50 100 00.20.40.60.8 80 100 120 140 160 Time (s) Pressure (mmHg) Ventricular Volume (mL) Ventricular pressure (mmHg) Ventricular volume (mL) 1 1 1 2 2 2 3 3 3 4 4 4 1.Isovolumetric contraction 2. Ventricular ejection 3.Isovolumetric relaxation 4.Ventricular filling 1 1 Stroke volume Stroke volume

18. P : Ventricular pressure V : Ventricular volume Ventricular work 6080100120140160 0 20 40 60 80 100 120 Ventricular Pressure (mmHg) Ventricular volume (mL)  1 J

19. Effect of systemic hypertension 80120160 0 100 200 80120160 0 100 200 00.511.5 0 100 200 00.511.5 0 100 200 Normal pressures Severe hypertension 1 J 1.5 J

20. Ventricular work as a f(preload,afterload)

21. Factors influencing flow and pressure

22. Mean pressure (MAP) and pulsed pressure (PP) MAP  2/3 DP + 1/3 SP PP = SP  DP SP (systolic pressure) DP (diastolic pressure) MAP (mean pressure) PP

23. Normal conditions (120/80 mmHg) :R = 1.1 mmHg.s/mL C = 2.0 mL/mmHg Severe hypertension (190/115 mmHg) :R = 1.7 mmHg.s/mL C = 0.8 mL/mmHg Resistance and compliance Resistance : R  MAP / CO MAP : mean arterial pressure CO : cardiac output Compliance : C  SV / PP SV : stroke volume PP : pulse pressure

24. Normal flow rate : SV = 70 mL, CO = 5L/min Resistance : R  MAP / CO R increases  MAP increases Compliance : C  SV / PP C decreases  PP increases 00.511.5 0 50 100 mmHg MAP PP Resistance and compliance

25. Hypertension and aortic pressure 00.511.5 0 100 200 00.511.5 0 100 200 Normal (120 / 80) Severe hypertension (190 / 115) MAP PP R = 1.1 mmHg.s / mL C = 2.0 mL / mmHg MAP = 95 mmHg PP = 40 mmHg R = 1.7 mmHg.s / mL C = 0.8 mL / mmHg MAP = 140 mmHg PP = 75 mmHg MAP PP 140 95

26. Arterial Pressure Flow, resistance and compliance of the arterial system are significant determinants of arterial pressure Another parameter that can determine arterial pressure is wave reflection in the arterial system.

27. Arterial pressure and wave reflection aorta Femoral a artery dorsalis pedis

28. ...................................................................................................................................................................................................................................................... Incident wave Reflected wave Arterial pressure and wave reflection

29. Heart Sounds

30. Two heart sounds can be distinguished: S1 and S2. S1 is synchronized with early systolic phase. S2 is synchronized with the end of systolic phase. The frequencies are between 10 and 500 Hz with low intensity Heart Sounds

31. 1 st stethoscope 1816 Laennec was examining a young female patient He was embarrassed to place his ear to her chest Rolled up 24 sheets of paper, placed one end to his ear and the other end to the woman’s chest Discovered that the sounds were also louder and clearer

32. Examples of stethoscopes In 1819, the French doctor René Laënnec invented the stethoscope.

33. En 1851, Dr. Marsh developed the 1st commercial model. Examples of stethoscopes

34. Pathological heart sounds Several pathologies induce turbulence in the flow in the cardiovascular system. High frequencies in the turbulent flow generate audible sounds.

35. Aortic stenosis Animation: http://www.healthcentral.com/heart-disease/valves/

36. Aortic valve Normal vs Stenosed Aortic valve Normal vs Stenosed

37. Aortic stenosis : different origins Congenital Rhumatismal Calcification

38. Aortic stenosis Valvular surgeries in Canada (1996-1997) The most common valvulopathy in industrial countries. Prevalence 1 to 2 % in people > 65 years old.

39. Carabello et al. NEJM, 1997 Aortic stenosis

40. Symptoms Angina pectoris Syncope Intolerance to exercise

41. Investigation of the severity of aortic stenoses - Gorlin Equation - Energy loss coefficient

42. Valve replacement Xeno-valves : pericardial or porcine Homo-valves : human Ross procedure Biological valves : Cage-ball : Starr-Edwards Bi-leaflet : St-Jude Mono-leaflet : Björk-Shiley Mechanical valves :

43. Bioprosthetic valves Pericardial valves Porcine valves

44. Mechanical valves Caged-ball : 1960 (Starr-Edwards) Bi-leaflet : Mono-leaflet :

45. Surgery

46. Stenosed valveMechanical valve http://heart-surgeon.com Animation: http://www.healthcentral.com/heart-disease/valves/

47. Cardiovascular Structure & Function Cardiovascular Structure & Function