Cardiovascular System

Transcription

1 Cardiovascular System Chapter 8 1 Cardiovascular System Functions: pump saturated oxygenated blood into arterial system cells pump desaturated deoxygenated blood to lungs via veins for reoxygenation Heart size depends on persons size size of fist 2 1

2 Anatomy of the Heart Four Chambers: Right atrium Left atrium Right ventricle Left ventricle Four Valves: Two atrioventricular (AV) 1. tricuspid 2. mitral Two semilunar (SL) 1. pulmonic 2. aortic 3 Heart Chambers Left Atrium Right Atrium Right Ventricle Left Ventricle Apex 4 2

3 2 Types of Valves AV valves - mitral between LA & LV - tricuspid between RA & RV Prevents backflow during contraction - systole Semilunar valves - prevent backflow during relaxation of ventricles - diastole 5 Heart Valves Pulmonary Veins Mitral Left Tricuspid Right Apex 6 3

4 7 The right ventricle occupies most of the anterior surface of the cardiac surface. Inferior border lies below the junction of the sternum and the xiphoid process. RV narrowed superiorly and meets at 3ed costal cartilage. LV : apical Impulse 5 th ICS MCL. RA and LA not identified in the physical examination. 8 4

5 9 Coronary Circulation 10 5

6 Four Chambers Right atrium (deoxygenated bld) Right ventricle (to lungs) Left atrium (receives oxygenated blood) Left ventricle (to systemic circulation) 11 Pulmonary and Systemic Circuits Systemic Circuit Left side of heart Pumps oxygenated blood to body via arteries Returns deoxygenated blood to right heart via veins Pulmonary Circuit Right side of heart Pumps deoxygenated blood to lungs via pulmonary arteries Returns oxygenated blood to left heart via pulmonary veins 12 6

7 13 Cardiac Cycle It has two phases: (A) Diastole ventricles relax & fill with blood (This is 2/3 of the cardiac cycle.) (B) Systolic heart contracts & pushes blood out of the ventricles to: (i) the lungs (ii) systemic arteries 14 7

8 15 Cardiac Cycle Systole & Diastole = 1 heartbeat Systole - period when ventricles contract & eject blood - mitral & tricuspid close - S1 produced 16 8

9 Cardiac Cycle Diastole - ventricles in relaxed state - atria contract blood to ventricles - aortic & pulmonary valve close - S2 produced 17 Heart Sounds S1 when closure of the AV valves (tricuspid & mitral) & ventricles contract S2 when closure of the semilunar valves ( pulmonic & aortic) & the ventricles relax 18 9

10 Extra Heart Sounds S3 This occurs immediately after S2 Why? Resistance to filling of ventricles Note: also called a ventricular gallop *It is caused by overload. * use diaphragm (it is a high sound) S4 - This occurs at the end of diastole, just before the next S1. Why? The atrium contract & push blood into a non-compliant ventricles. Note: also called an atrial gallop *caused by HTN, CAD, Aortic stenosis, cardiomyopathy * Use bell to listen as it is a low sound

11 Heart murmur Distinguished from heart sound by their longer duration. Indicate serious heart disease. Cause by a stenotic valver orifice (abnormal narrowed). A systolic murmur may occure with normal heart or with heart disease. Diastole murmur always indicate heart disease. 21 Murmurs Caused by turbulence Therefore we hear a gentle blowing, swooshing sound. Why? 1. Velocity of blood increases (eg. exercise, thyrotoxicosis) 2. Velocity of blood decreases (eg. anemia) 3. Structural defect in the valves or an unusual opening occurs in the chambers 22 11

12 Grading of Murmurs Use VI point grading scale & record as a fraction (ie. I/VI or II/VI) Grades: Grade I barely audible, heard only in a quiet room & then with difficulty Grade II clearly audible, but faint Grade III moderately loud, easy to hear Grade IV loud, associated with a thrill palpable on the chest wall Grade V very loud, heard with one corner of the stethoscope lifted off the chest wall Grade VI loudest, still heard with the entire stethoscope lifted off the chest 23 Conduction System 1-SA Node (Pacemaker) 2-AV Node 3-Bundle of His 4-Perkinje fibers 24 12

13 Conduction System of the Heart 25 Electrocardiogram Records electrical activity of the heart P wave Atrial depolarization QRS complex Ventricular depolarization T wave Ventricular repolarization 26 13

14 EKG Electrical activity recorded as specific waves. Records 2 Electrical Events: 1. Depolarization - spread of impulse through heart 2. Repolarization - return of heart muscle to resting state. Sequence of R & D = ACTION POTENTIAL 27 EKG other terms: Conductivity - cells ability to conduct & transmit electrical impulse Contractility - ability of fibers to contract P waves QRS complex ST segment - contractility = C.O. EKG 28 14

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16 The heart as a pump Cardiac Output: The amount of blood pumped from the left ventricle each minute Cardiac Output = Heart Rate X Stroke Volume Heart Rate Number of times ventricles contract each minute Normal adult Stroke Volume Amount of blood ejected by the ventricles during each systole 31 Stroke Volume (SV) determined by Preload Contractility Afterload 32 16

17 Preload Degree of myocardial fiber stretch at the end of diastole and just before contraction Determined by LVED pressure and blood return from the venous system Starlings Law: the more the heart fills during diastole, the more forcefully it contracts Afterload Pressure or resistance that the ventricles must overcome to eject blood through the semilunar valves and into the peripheral blood vessels. Contractility The force of cardiac contraction independent of preload Increased by:sympathetic stimulation,calcium release Decreased by: Hypoxia and acidemia 33 Preload and Afterload 34 17

18 35 Blood Pressure Measure of pressure exerted by blood against walls of arteries. Systolic - pressure when heart contracts Diastolic - pressure with relaxation 36 18

19 Postural BP Changes Compare and contrast normal and abnormal blood pressure responses to postural position changes. What do orthostatic changes indicate? 37 Jugular venous pressure & pulses Systematic venous pressure is much lower than arterial pressure. Wall of veins contain less smooth muscle than arterial wall. Venous pressure fall when left venticular out put or blood volume is significantly reduced. Pressure in the jugular vein reflect right atrial pressure

20 The Neck Vessels The Carotid Artery The Jugular Venous Pulse & Pressures 2 components: (a) internal jugular (b) external jugular 39 Neck Vessels 40 20

21 The Health Hx Common or Concerning Symptoms Chest pain. Palpitation. Shortness of breath: dyspnea, orthopnea, or paroxysmal nocturnal dyspnea. Swelling or edema. Assessment. History - major symptom, chest pain. P - exercise, straining, activity, emotional - rest, O2 Q - crushing, heavy, dull, burning, pressure (own words) R - (L) Anterior chest - (R) arm, jaw, neck, shoulders S - anorexia, N & V - SOB, anxious, sweaty, dizzy T - constant, intermittent, sudden, insidious 42 21

22 Palpitation Palpitations are an unpleasent awareness of the heart beat. Patients use various terms such as: Skipping, Racing, Pounding, Fluttering, or Stopping the heart. Are you ever aware of your heart beat?. Ask Pt about the rhythem( was it fast or slow, regular, irregular). Shortness Of Breath Dyspnea is uncomfortable awarness of breathing that is inappropriate to a given level if exertion. Orthopnea is duspnea that occurs when the Pt lying down and improves when the Pt sits up. Paroxysmal Nocturnal Dyspnea PND, describes epispdes of sudden dyspnea & orthopnea that awaken the Pt from sleep, usually 1or 2 hrs after going to bed, prompting the Pt to sit up, stand up, or go to window for air. There may be associated with wheezing & coughing

23 Assessment continuo Cough Fatique Cyanosis or pallor Edema Past cardiac history Family cardiac history Personal habits Environment 45 Additional Assessment Areas Health perception and management Nutrition and metabolism Elimination Activity and exercise Sleep rest patterns Cognition and perception Self-perception and self-concept Roles and relationships Sexuality and reproduction Coping and stress tolerance 46 23

24 Physical Exam Cyanosis clubbing edema capillary refill pulse - rate, rhythm, strength pulse pressure - 120/80 pp - 40 General appearance - distress, color, LOC Urinary output - kidney perfusion 47 Assessing for Clubbing 48 24

25 Recommended Sequence for assessing cardiovascular system 1. Pulses & BP 2. Extremities 3. Neck Vessels 4. Precordium 49 Heart Rate or Pulse - Evaluate for Rate Adults Children Newborns < normal = bradycardia > normal = tachycardia Rhythm Regular or irregular Irregular beat may indicate arrhythmias Strength Bounding? Arteriosclerosis Weak and thready? shock 50 25

26 Blood Pressure Classification Category Systolic (mmhg) Diastolic (mmhg) Hypertension Stage 3 (sever) Stage 2 (moderate) Stage 1 ( mild) High Normal Normal < 130 < 85 Optimal < 120 < The Neck Vessels A. Carotid Arteries Palpate low in neck to avoid the sinus Be gentle Palpate only one side at a time to avoid compromising blood flow to the head Auscultate using the bell Listen in 3 places: angle of jaw midcervical area base of neck 52 26

27 53 Assessment of the Jugular Vein Purpose: To measure the central venous pressure Method: Position 45 degree angle at the hip, Turn head slightly away, Use a strong light tangentially, Observe the external jugular over the sternomastoid muscle 54 27

28 Specific Process for CVP Measurement Locate the internal jugular pulsation Mark the highest point of pulsation Locate the angle of Louis Make a T square with 2 index cards Read the level of intersection Note: The normal jugular venous pressure is 2 cm or less above the sternal angle. 55 Jugular Vein Pressure 56 28

29 Elevated JVP: Right-sided CHF, constrictive pericarditis, tricuspid stenosis, or superior vena cava obstruction. Low JVP: Hypovolemia. 57 Hepatojugular Reflux This is measured if the CVP (central venous pressure) is elevated or CHF is suspected. Patient is supine Instruct patient to breathe quietly with mouth open With rt. hand on the patient s RUQ of abdomen, just below the rib cage, exert firm consistent pressure for 30 seconds Watch the level of the jugular pressure Note: Normally the jugular rises but recedes back. Abnormally, the pressure elevates & stays

30 Hepatojugular Reflex 59 Congestive Heart Failure( CHF) 60 30

31 The Heart ( Precordium) Inspection: Check pulsations, heaves, lifts (You may see the apical pulse.) Note: The apical is located in the 4 th or 5 th the left MCL. Palpate: Feel the apical impulse (also called the PMI). * Use 1 finger pad. Use palmar side of 4 fingers to feel for other pulsations on the chest.(eg. thrills 61 Palpation Note any thrills Palpate the PMI 62 31

32 Palpation Percussion Percussion: To check for heart enlargement (Note:often done by chest Xray) 64 32

33 Auscultation 1. Position the patient supine with the head of the table slightly elevated. 2. Always examine from the patient's right side. A quiet room is essential. 3. Listen with the diaphragm at the right 2nd intercostal near the sternum (aortic area). 4. Listen with the diaphragm at the left 2nd intercostal near the sternum (pulmonic area). 5. Listen with the diaphragm at the left 3rd, 4th, and 5th interspaces near the sternum (tricuspid area). 65 Auscultation 6. Listen with the diaphragm at the apex (mitral area). 7. Listen with the bell at the apex. 8. Listen with the bell at the left 4th and 5th intercostal near the sternum. 9. Have the patient roll on their left side. Listen with the bell at the apex. This position brings out S3 and mitral murmurs. 10. Have the patient sit up, lean forward, and hold their breath in exhalation. Listen with the diaphragm at the left 3rd and 4th intercostal near the sternum. This position brings out aortic murmurs. 11. Record S1, S Auscultate the carotid arteries

34 Heart Assessment (continued) Auscultation: Start at the base of the heart. APE to Man Aortic - 2 nd Rt. ICS Pulmonic 2 nd left ICS Erb s Point Tricuspid left sternal border Mitral 5 th left MCL 67 Sequence for Auscultating A. Begin with the diaphragm. Note at each area: 1. rate & rhythm 2. identify S1 and S2 3. assess S1 and S2 separately 4. listen for extra heart sounds (ie. S3,S4) 5. listen for murmurs B. Repeat above using the bell

35 What do you hear? S1 and S2 sound like lub-dup S1 is louder than S2 at the apex S2 is louder than S1 at the base S1 coincides with the carotid pulsation

36 Auscultatory Areas 71 Relationship of auscultatory finding to the chest wall Sounds & murmurs arising from the mitral valve are usually heared best at & around the cardiac apex. The sound originated in the tricuspid valve are heard best at or near the lower left sternal border. Murmur arising from pulmonic valve heard best in the 2 nd left ICS close to the sternum. The sound originated in the aortic valve may heard any where from Rt 2 nd ICS to the apex. The base of the heart refers to the Rt & Lt 2 nd ICS close to the sternum

37 First and Second Heart sound 73 Sounds S1(Lub) & S2(Dub) 74 37

38 Extra Heart Sounds S3 Due to Rapid ventricular filling: ventricular gallop S1 -- S2-S3 (Ken--tuc-ky) S4 Due to slow ventricular contraction: atrial gallop S4-S1 S2 (Ten-nes see) 75 Murmurs turbulent blood flow within the heart Listen for murmurs in the same auscultatory sites APETM Grading of murmurs (I/VI -VI/VI) 76 38

39 THE END Thank You 77 39