CHAPTER 10 Cardiovascular System Cardiovascular System Overview Responsibilities

CHAPTER 10 Cardiovascular System

Cardiovascular System Overview • Responsibilities of cardiovascular system – Pumping blood to the body tissues and cells – Supplying oxygen and nutrients to tissues and cells – Removing carbon dioxide and other waste products of metabolism from tissues and cells 2

Cardiovascular System • Heart – Center of the circulatory system – Enclosed by pericardium • Parietal pericardium • Visceral pericardium • Pericardial cavity – Three layers of the heart • Epicardium • Myocardium • Endocardium 3

Heart • Chambers – Right atrium and left atrium • Upper chambers • Receiving chambers – Right ventricle and left ventricle • Lower chambers • Pumping chambers 4

Heart • Partitions – Interatrial septum • Separates right and left sides of atria – Interventricular septum • Separates right and left sides of ventricles 5

Circulation Through the Heart • Deoxygenated blood – Enters right atrium from superior vena cava • Brings blood from head, thorax, upper limbs, and abdominal viscera – Also enters right atrium from inferior vena cava • Brings blood from the trunk, lower limbs, and abdominal viscera 6

Circulation Through the Heart • Deoxygenated blood travels: – From right atrium through tricuspid valve into right ventricle – From right ventricle through pulmonary valve into right and left pulmonary arteries – From pulmonary arteries to lungs • Pulmonary arteries are the only arteries that carry deoxygenated blood • Exchange of gases takes place in the lungs 7

Circulation Through the Heart • Oxygenated blood – Enters left atrium from lungs via pulmonary veins • Pulmonary veins only veins in body that carry oxygenated blood – From left atrium through mitral valve into left ventricle – From left ventricle through aortic valve into aorta – From aorta to arteries to each body part and region 8

Circulation Through the Heart • Pulmonary circulation – Circulation of blood from the heart to the lungs for oxygenation and back to the heart • Systemic circulation – Circulation of blood from the heart to all parts of the body and back to the heart 9

Circulation Through the Heart • Coronary arteries – Arise from aorta near its origin at left ventricle – Supply blood to heart muscle – Heart muscle has a greater need for oxygen and nutrients • Heart uses approximately 3 times more oxygen than other body organs 10

Conduction System of the Heart • Sinoatrial Node (SA Node) sets rhythm for entire heart – SA Node = pacemaker of the heart – Impulse from SA node causes atria to contract • Impulse travels from SA node to Atrioventricular node (AV node) 11

Conduction System of the Heart • Impulse from AV node travels to ventricles through Bundle of His – Bundle of His divides into right and left bundle branches • Bundle branches terminate in Purkinje fibers – Purkinje fibers fan out into the muscles of the ventricles – Purkinje fibers cause ventricles to contract 12

Supporting Blood Vessels • Arteries – Large, thick-walled vessels – Carry blood away from the heart • Arterioles – Thinner walls than arteries – Transport blood on to capillaries • Capillaries – Extremely thin walls = single layer – Allow for exchange of materials between blood and tissue fluid surrounding body cells 13

Supporting Blood Vessels • Venules – Smallest veins – Collect deoxygenated blood from cells for transport back to heart • Veins – Thinner walls than arteries • Thicker walls than capillaries – Transport blood from venules to heart 14

Cardiac Cycle • One Cardiac Cycle = One Complete Heartbeat • Diastole – Relaxation phase of heartbeat – Ventricles relax and fill with blood • Systole – Contraction phase of heartbeat – Ventricles contract • Force blood out of heart 15

Blood Pressure • Blood Pressure – Pressure exerted by blood on walls of arteries • Systolic Pressure – Maximum pressure reached within the ventricles • Diastolic Pressure – Minimum pressure reached within the ventricles • Sphygmomanometer = blood pressure cuff – Used to measure blood pressure 16

Common Signs and Symptoms • Symptoms that may indicate cardiovascular problems Anorexia Anxiety Bradycardia Chest pain Cyanosis Dyspnea Edema Fatigue Fever Headache Nausea Pallor Palpitation Sweat Tachycardia Vomiting --------------- Weakness 17

PATHOLOGICAL CONDITIONS Cardiovascular System

Angina Pectoris • Pronounced – (an-JI-nah PECK-tor-is) – (AN-jin-nah PECK-tor-is) • Defined – Severe pain and constriction about the heart, usually radiating to left shoulder and down left arm • Creates feeling of pressure in anterior chest 19

Cardiac Tamponade • Pronounced – (CAR-dee-ak TAM-poh-nod) • Defined – Compression of the heart caused by accumulation of blood or other fluid within the pericardial sac • Accumulation of fluid in pericardial cavity prevents ventricles from adequately filling or pumping blood 20

Cardiomyopathy • Pronounced – (car-dee-oh-my-OP-ah-thee) • Defined – Disease of the heart muscle itself, primarily affecting pumping ability of the heart • Noninflammatory disease of the heart • Results in enlargement of the heart and dysfunction of the ventricles of the heart 21

Congestive Heart Failure • Pronounced – (con-JESS-tiv heart failure) • Defined – Condition in which pumping ability of heart is progressively impaired to the point that it no longer meets bodily needs 22

Congestive Heart Failure • Left-sided cardiac failure – Left ventricle unable to pump blood that enters from the lungs – Characteristics: • • • Dyspnea Moist sounding cough Fatigue Tachycardia Restlessness Anxiety 23

Congestive Heart Failure • Right-sided cardiac failure – Right side of heart cannot empty blood received from venous circulation – Characteristics: • Edema of lower extremities (pitting edema) • Weight gain • Enlargement of liver (hepatomegaly) • Distended neck veins • Ascites • Anorexia • Nocturia • Weakness 24

Coronary Artery Disease • Pronounced – (KOR-oh-nah-ree AR-ter-ee dih-ZEEZ) • Defined – Narrowing of the coronary arteries to the extent that adequate blood supply to the myocardium is prevented 25

Coronary Artery Disease • Treatments for occluded coronary arteries – Medications – Percutaneous Transluminal Coronary Angioplasty (PTCA) – Directional Coronary Atherectomy – Coronary Bypass Surgery = Coronary Artery Bypass Graft (CABG) 26

Endocarditis • Pronounced – (en-doh-car-DYE-tis) • Defined – Inflammation of the membrane lining of the valves and chambers of the heart • Caused by direct invasion of bacteria or other organisms • Leads to deformity of valve cusps 27

Hypertensive Heart Disease • Pronounced – (high-per-TEN-siv heart dih-ZEEZ) • Defined – Heart disease as a result of long-term hypertension • Heart must work against increased resistance due to increased pressure in the arteries 28

Mitral Valve Prolapse • Pronounced – (MY-tral valve proh-LAPS) • Defined – Drooping of one or both cusps of the mitral valve back into the left atrium during ventricular systole • Results in incomplete closure of the valve and mitral insufficiency 29

Myocardial Infarction • Pronounced – (my-oh-CAR-dee-al in-FARC-shun) • Defined – Condition caused by occlusion of one or more of the coronary arteries = destruction of myocardial tissue – Heart attack • Life-threatening condition 30

Myocarditis • Pronounced – (my-oh-car-DYE-tis) • Defined – Inflammation of the myocardium • May be viral or bacterial infection • May be result of systemic disease • May be caused by fungal infections, serum sickness, or chemical agent 31

Pericarditis • Pronounced – (per-ih-car-DYE-tis) • Defined – Inflammation of the pericardium (saclike membrane) that covers the heart muscle • May be acute or chronic 32

Rheumatic Fever • Pronounced – (roo-MAT-ic fever) • Defined – Inflammatory disease that may develop as a delayed reaction to insufficiently treated Group A beta-hemolytic streptococcal infection of the upper respiratory tract 33

PATHOLOGICAL CONDITIONS Blood Vessels

Aneurysm • Pronounced – (AN-yoo-rizm) • Defined – Localized dilatation of an artery formed at a weak point in the vessel wall • Weakened area balloons out with each pulsating of artery 35

Arteriosclerosis • Pronounced – (ar-tee-ree-oh-skleh-ROH-sis) • Defined – Arterial condition in which there is thickening, hardening and loss of elasticity of the walls of arteries (hardening of the arteries) • Results in decreased blood supply, especially to lower extremities and cerebrum 36

Hypertension • Pronounced – (high-per-TEN-shun) • Defined – Condition in which the patient has a higher blood pressure than judged to be normal • Blood pressure persistently exceeds 140/90 mm. Hg 37

Hypertension • Essential hypertension – Accounts for 90 percent of all hypertension – No single known cause • Secondary hypertension – Due to underlying cause • Malignant hypertension – Severe and rapidly progressive – Diastolic pressure higher than 120 mm. Hg 38

Peripheral Arterial Occlusive Disease • Pronounced – (per-IF-er-al ar-TEE-ree-al occlusive disease) • Defined – Obstruction of the arteries in the extremities (predominantly the legs) • Leading cause = atherosclerosis • Classic symptom = intermittent claudication 39

Raynaud’s Phenomenon • Pronounced – (ray-NOZ phenomenon) • Defined – Intermittent attacks of vasoconstriction of the arterioles • Causes pallor of the fingers or toes, followed by cyanosis, then redness, before returning to normal color (white-blue-red) • Initiated by exposure to cold or emotional disturbance 40

Thrombophlebitis • Pronounced – (throm-boh-fleh-BY-tis) • Defined – Inflammation of a vein associated with the formation of a thrombus (clot) • Usually occurs in an extremity, most frequently a leg 41

Thrombophlebitis • Superficial Thrombophlebitis – Usually obvious – Accompanied by cordlike or thready appearance to the vessel • Deep Vein Thrombosis (DVT) – Occurs primarily in lower legs, thighs, and pelvic area – Characterized by aching or cramping pain in legs 42

Varicose Veins • Pronounced – (VAIR-ih-kohs veins) • Defined – Enlarged, superficial veins – Twisted, dilated veins with incompetent valves 43

Varicose Veins • Treatment – Rest and elevation of affected extremity – Use of elastic stockings – Sclerotherapy • Injection of a chemical irritant into the varicosed vein (sclerosing agent) – Vein stripping 44

Venous Insufficiency • Pronounced – (VEE-nuss in-syoo-FISH-in-see) • Defined – An abnormal circulatory condition characterized by decreased return of venous blood from the legs to the trunk of the body 45

PATHOLOGICAL CONDITIONS Congenital Heart Diseases

Coarctation of the Aorta • Pronounced – (koh-ark-TAY-shun of the aorta) • Defined – Congenital heart defect characterized by a localized narrowing of the aorta • Results in increased blood pressure in upper extremities and decreased blood pressure in lower extremities 47

Patent Ductus Arteriosus • Pronounced – (PAY-tent DUCK-tus ar-tee-ree-OH-sis) • Defined – Abnormal opening between the pulmonary artery and the aorta caused by failure of fetal ductus arteriosus to close after birth • Defect seen primarily in premature infants 48

Tetralogy of Fallot • Pronounced – (teh-TRALL-oh-jee of fal-LOH) • Defined – Congenital heart anomaly that consists of four defects • • Pulmonary stenosis Interventricular septal defect Dextraposition of aorta (shifts to the right) Hypertrophy of right ventricle 49

Transposition of the Great Vessels • Pronounced – (tranz-poh-ZIH-shun of the great vessels) • Defined – Condition in which the two major arteries of the heart are reversed in position • Results in two non-communicating circulatory systems 50

PATHOLOGICAL CONDITIONS Arrhythmias

Atrial Flutter • Pronounced – (AY-tree-al flutter) • Defined – Condition in which the contractions of the atria become extremely rapid, at the rate of between 250 to 400 beats per minute 52

Fibrillation (Atrial Fibrillation) • Pronounced – (atrial fih-brill-AY-shun) • Defined – Extremely rapid, incomplete contractions of the atria resulting in disorganized and uncoordinated twitching of the atria • Rate of contractions may be as high as 350 to 600 beats per minute 53

Fibrillation (Ventricular Fibrillation) • Pronounced – (ventricular fih-brill-AY-shun) • Defined – Rapid, tremulous (quivering like a bowl of Jell. O) and ineffectual contractions of the ventricles • • • No audible heartbeat No palpable pulse No respiration No blood circulation If prolonged, will lead to cardiac arrest 54

Heart Block (AV) • Pronounced – (Heart Block) • Defined – An interference with the normal conduction of electric impulses that control activity of the heart muscle 55

Ventricular Tachycardia • Pronounced – (ven-TRIK-yoo-lar tak-ee-CAR-dee-ah) • Defined – Condition in which the ventricles of the heart beat at a rate greater than 100 beats per minute • Characterized by three or more consecutive premature ventricular contractions – Also known as V-tach 56

DIAGNOSTIC TECHNIQUES, TREATMENTS AND PROCEDURES Cardiovascular System

Diagnostic Techniques, Treatments, and Procedures • Angiography – X-ray visualization of internal anatomy of heart and blood vessels after introducing a radiopaque substance (contrast medium) – Promotes imaging of internal structures that are otherwise difficult to see on X-ray film • Substance is injected into an artery or a vein 58

Diagnostic Techniques, Treatments, and Procedures • Cardiac catheterization – Diagnostic procedure in which a catheter is introduced into a large vein or artery, usually of an arm or a leg, and is then threaded through the circulatory system to the heart • Used to obtain detailed information about the structure and function of the heart chambers, valves, and the great vessels 59

Diagnostic Techniques, Treatments, and Procedures • Cardiac Enzymes Test – Tests performed on samples of blood obtained by venipuncture to determine the presence of damage to the myocardial muscle • (CAT) Computed Axial Tomography – Diagnostic X-ray technique that uses ionizing radiation to produce a cross-sectional image of the body • Often used to detect aneurysms of the aorta 60

Diagnostic Techniques, Treatments, and Procedures • Echocardiography – Diagnostic procedure for studying the structure and motion of the heart • Useful in evaluating structural and functional changes in a variety of heart disorders • Electrocardiogram (EKG, ECG) – Graphic record of the electrical action of the heart as reflected from various angles to the surface of the skin 61

Diagnostic Techniques, Treatments, and Procedures • Exercise stress testing – Means of assessing cardiac function, by subjecting the patient to carefully controlled amounts of physical stress, for example, using the treadmill 62

Diagnostic Techniques, Treatments, and Procedures • Holter monitoring – Small, portable monitoring device that makes prolonged electrocardiograph recordings on a portable tape recorder • Continuous EKG (ambulatory EKG) is recorded on a magnetic tape recording while the patient conducts normal daily activities 63

Diagnostic Techniques, Treatments, and Procedures • Event monitor – Similar to the Holter monitor in that it also records the electrical activity of the heart while patient goes about usual daily activities – Can be used for a longer period of time than a Holter monitor • Usually a month 64

Diagnostic Techniques, Treatments, and Procedures • Implantable Cardioverter Defibrillator (ICD) – Small, lightweight, electronic device placed under the skin or muscle in either the chest or abdomen to monitor the heart’s rhythm – If abnormal rhythm occurs, the ICD helps return the heart to its normal rhythm 65

Diagnostic Techniques, Treatments, and Procedures • Magnetic Resonance Imaging (MRI) – Use of strong magnetic field and radiofrequency waves to produce imaging that is valuable in providing images of the heart, large blood vessels, brain, and soft tissue • Used to examine the aorta, to detect masses or possible tumors, and pericardial disease • Can also show the flowing of blood and the beating of the heart 66

Diagnostic Techniques, Treatments, and Procedures • Positron Emission Tomography (PET) – Computerized x-ray technique that uses radioactive substances to examine the blood flow and the metabolic activity of various body structures, such as the heart and blood vessels • Patient is given doses of strong radioactive tracers by injection or inhalation • Radiation emitted is measured by the PET camera 67

Diagnostic Techniques, Treatments, and Procedures • Serum Lipid – Test that measures the amount of fatty substances (cholesterol, triglycerides, and lipoproteins) in a sample of blood obtained by venipuncture • Thallium Stress – Combination of exercise stress testing with thallium imaging to assess changes in coronary blood flow during exercise 68