CVS PSL and Monitoring

By Dr.Tariq

1. Cardiovascular Physiology and Monitoring Tariq AlZahrani M.D Assistant professor College of medicine King Saud University

2. Coronary Circulation Blood Supply RCA LCA Conduction System SAN AVN Coronary Perfusion Pressure (50-120mmHg) ADBP – LVEDP

3. Cardiac Cell Types • Electrical cells Generate and conduct impulses rapidly • SA and AV nodes • Nodal pathways • No contractile properties • Muscle (myocardial) cells Main function is contraction • Atrial muscle • Ventricular muscle • Able to conduct electrical impulses • May generate its own impulses with certain types of stimuli

4. PURKINJE FIBERS BUNDLE BRANCHES Sino-atrial (SA) node Atrio-ventricular (AV) node

5. INTERCALATED DISC (TIGHT JUNCTION)

6. Nerve impulse Terminology • Resting state The relative electrical charges found on each side of the membrane at rest • Net positive charge on the outside • Net negative charge on the inside • Action Potential Change in the electrical charge caused by stimulation of a neuron

7. Action Potential Terms • Depolarization The sudden reversal of electrical charges across the neuron membrane, causing the transmission of an impulse • Minimum voltage must be met in order to do this • Repolarization Return of electrical charges to their original resting state

8. Automaticity (P Cells) Prepotential , Resting Potential, Diastolic Depolarization Action Potential Repolarization Factors That Affect Automaticity: Sympathetic and parasympathetic outflow will affect the prepotential phase Temperature RA and SAN stretch Hormones Drugs Distribution Of P Cells

9. Conduction Speed A-V nodal conduction: One way conduction A-V nodal Delay (0.1 sec ) Factors Affecting Conductivity: Sympathetic and vagal infuince Temperature Hormons Ischemia Acidosis Drugs

10. MEMBRANE POTENTIAL (mV) -90 1 2 3 4 TIME PHASE 0 = Rapid Depolarization (inward Na + current) 1 = Overshoot (outward K + current) 2 = Plateau (inward Ca ++ current) 3 = Repolarization (outward K + current) 4 = Resting Potential Mechanical Response (outward K + current) (inward Na + current)

11. MEMBRANE POTENTIAL (mV) -50 -50 -100 -100 SAN VENTRICULULAR CELL ACTION POTENTIALS 1 2 3 4 4 3

12. Cardiac Myocyte Structure Ca ++ Release Excitation-Contraction Coupling

13. The Fibrous A-V Ring

14. THE ANATOMY OF BLOOD VESSELS Layers: Tunica interna ( intima ) Tunica media Tunica externa (adventitia)

15. Comparison of Veins and Arteries Arteries: Veins:

16. The Distribution of Blood

17. Cardiac Output CO = SV x HR • The amount of blood ejected from the ventricle in one minute • Stroke volume Amount of blood ejected from the ventricle in one contraction • Heart rate The # of cardiac cycles in one minute

18. Determination of Stroke Volume • Preload Amount of blood delivered to the chamber Depend upon venous return to the heart Also dependent upon the amount of blood delivered to the ventricle by the atrium • Contractility The efficiency and strength of contraction Frank Starling’s Law • Afterload Resistance to forward blood flow by the vessel walls

19. • End-diastolic volume (110-120 mL ) • End-systolic volume (40-50 mL ) • Stroke volume (70 mL ) • Ejection fraction (60%)

20. Pressure-Volume Loops

21. Volume Load ► Pressure Load ►

22. Regulation of Cardiovascular System Neural Mechanisms Vasoconstriction Vaosdilation Baroreceptors Chemoreceptors

23. Nerve Supply of the Conduction System

24. HORMONAL REGULATION Epinephrine & Norepinephrine From the adrenal medulla Renin-angiotensin-aldosterone Renin from the kidney Angiotensin , a plasma protein Aldosterone from the adrenal cortex Vasopressin ( Antidiuretic Hormone-ADH ) _ ADH from the posterior pituitary ANP from RA

25.  BP (Kidney) Renin Angiotensinogen (renin substrate) Angiotensin Aldosterone Kidney  sodium & water retention Vasoconstriction Venoconstriction RENIN-ANGIOTENSIN-ALDOSTERONE MECHANISM

26. Hypothalamic Osmoreceptors  BP via Posterior Pituitary  Vasopressin (ADH) Vasoconstriction  Water Venoconstriction Retention VASOPRESSIN (ANTIDIURETIC HORMONE)

27. How To interpret ECG? 1. Rate? 2. QRS Duration? 3. Stability?

28. ECG limb leads

29. Normal ECG

30. P wave corresponds to depolarization of SA node QRS complex corresponds to ventricular Depolarization T wave corresponds to ventricular repolarization Atrial repolarization record is masked by the larger QRS complex

31. Measurements Small square = 0.04 sec. Large square = 5 small square = 0.2 sec. One second = 5 large square. One minute = 300 large square.

32. P duration = 3 small sqs = 0.12 sec. P height = 3 small sqs = 0.12 sec. QRS duration= 3 small sq =0.12 sec. P-R interval = 5 small sq = 0.2 sec . Remember This 3, 3, 3 and 5

33. Right ventricular hypertrophy ( precordial leads)

34. Left ventricular hypertrophy ( precordial leads)

35. QRS voltage decrease • Myocardial infarction (decrease of excitable myocardium mass) • Fluids in the pericardium (short-circuits of currents within pericardium) • Pulmonary emphysema (excessive quantities of air in the lungs)

36. J-point: ST-segment shift – sign of current of injury -Time point of completed depolarization (zero reference) -The junction of the QRS and the ST segment

37. Injury currents: constant source • Mechanical trauma • Infectious process • Ischemia

38. Ischemia = ST depression or T-wave inversion Represents lack of oxygen to myocardial tissue

39. Injury = ST elevation - - represents prolonged ischemia; significant when > 1 mm above the baseline of the segment in two or more leads

40. Infarct = Q wave — represented by first negative deflection after P wave; must be pathological to indicate MI

41. What part of the heart is affected ? II, III, aVF = Inferior Wall I II III aVR aVL aVF V1 V2 V3 V4 V5 V6

42. Which part of the heart is affected ? I II III aVR aVL aVF V1 V2 V3 V4 V5 V6 Leads V1, V2, V3, and V4 = Anterior Wall MI

43. What part of the heart is affected ? I, aVL, V5 and V6 Lateral wall of left ventricle I II III aVR aVL aVF V1 V2 V3 V4 V5 V6

44. I, aVL , V5 + V6 = Lateral Wall = Circumflex Artery Blockage

45. Rate If regular: Divide 300/ number of large squares between 2 Rs = HR If irregular: count number of complexes in 6 sec. and multiply by 10 - Normal 60 -100 - Bradycardia < 60 - Tachycardia > 100 P = Sinus No P = Non sinus

46. Rate > 100. QRS: Narrow. Stable or unstable. Rate < 60. QRS: Narrow. Stable or unstable. Sinus tachycardia . PSVT. Atrial flutter. Atrial fibrillations. Sinus bradycardia. 1 st degree HB. 2 nd degree HB. Complete HB. Supraventricular Rhythm

47. Supraventricular Rhythm: Tachycardia Sinus Tachycardia

48. Paroxysmal SVT Supraventricular Rhythm: Tachycardia

49. Atrial Flutter Supraventricular Rhythm: Tachycardia

50. Atrial Fibrillations Supraventricular Rhythm: Tachycardia

51. Supraventricular Rhythm: Bradycardia Sinus Bradycardia Normal Sinus Rhythm

52. Supraventricular Rhythm: Bradycardia 1 st Degree HB

53. Supraventricular Rhythm: Bradycardia 2 nd Degree HB: Mobitz 1 Wenckebach. Progressive lengthening of the P-R interval with intermittent dropped beat.

54. Supraventricular Rhythm: Bradycardia Sudden drop of QRS without prior P-R changes 2 nd Degree HB: Mobitz 2

55. Supraventricular Rhythm: Bradycardia 3 rd Degree HB

56. The right bundle brunch block ( precordial leads)

57. Left bundle branch block ( precordial leads)

58. Characteristics of PVCs • QRS prolongation due to slower conduction in the muscle fibers • QRS high amplitude due to lack of synchrony of excitation of RV and LV which causes partial neutralization of their contribution to the ECG • QRS and T-wave have opposite polarities, again due to slow conduction which causes repolarization to follow depolarization.

59. Ventricular Rhythm Idioventricular Rhythm.

60. Ventricular Rhythm Accelerated Idioventricular Rhythm.

61. Ventricular Rhythm

62. Ventricular Rhythm

63. Pacer Rhythm Ventricular Rhythm

64. Stability * Stable patient: think of drug therapy. * Unstable patient: think of electric therapy.

65. Treatment Supraventricular Rhythm: Stable = Drugs Adenosine. B blocker. Ca channel blocker. Digoxin . Unstable = Electric DC, Synchronized

66. Treatment Ventricular Rhythm: Stable = Drugs Amiodarone . Lidocaine . Procainamide . Unstable = Electric DC, Non Synchronized

67. Normal Venous Tracing a ► Atrial Contraction c ► Isometric (V) Contraction x ► Mid-Systole v ► Venous Filling (Atrial) y ► Rapid Filling (Ventricular)

68. THANK YOU