The Cardiovascular System

1. 15 Lecture Note PowerPoint Presentation The Cardiovascular System

2. LEARNING OUTCOME 1 Describe changes in the cardiovascular system that occur with aging.

3. Structure and Function of Cardiovascular System • Heart structure • Right atrium • Tricuspid valve • Right ventricle • Pulmonic valve

4. Figure 15-3The capillary network between arterial and venous blood.

5. Structure and Function of Cardiovascular System • Heart structure • Mitral valve • Left ventricle • Aortic valve • Pericardium

6. Structure and Function of Cardiovascular System • Heart function • Diastole • Systole • Cardiac output • Ejection fraction • Autonomic nervous system • Sympathetic: alpha and beta receptors (adrenergic) • Parasympathetic: vagus nerve

7. Structure and Function of Cardiovascular System • Heart function • Systole • Conduction system • Action potential noting the refractory period • Sinoatrial (SA) node • Atrioventricular (AV) node • Bundle branches

8. Structure and Function of Cardiovascular System • Heart function • Electrocardiogram (EKG) • P wave • P-R interval • QRS wave • T wave

9. Structure and Function of Cardiovascular System • Heart function • Circulatory system structure • Arteries • Tunica intima • Tunica media • Tunica adventitia • Capillaries • Endothelial layer • Basal lamina • Veins • Inferior and superior vena cava

10. Structure and Function of Cardiovascular System • Heart function • Circulatory system function • Regulation of blood flow • Local conditions • Release of nitric oxide → vasodilation • Metabolic activity • Cardiac circulation • Left coronary artery (LCA) • Left anterior descending (LAD) • Circumflex • Right coronary artery (RCA)

11. Wide Range of Cardiovascular Function Among Older Adults • Genetics • Conditioning • Effect of other aging organ systems • Different body systems age at different rates • Compensation ability • Comorbidities • Social and physical environments

12. Aging Changes with the Heart • Myocardium • Hypertrophy • Left ventricle wall 25% thicker in an 80-year-old person vs. a 30-year-old person • Increased collagen and connective tissue • Cardiac cells • Accumulation of lipofuscin, amyloid

13. Figure 15-4Normal changes of aging in the cardiovascular system.

14. Aging Changes with the Heart • Valves • Fibrosis and calcification → stiffening of valves • Changes in valve rings → contribute to stenosis or incompetence • Resting heart rate unchanged with age • Difficulty responding to stress • Small decline in cardiac output from age 20

15. Aging Changes with the Heart • Electrical activity • Decrease in number of normal pacemaker cells in SA node • After age 75 < 10% still functional • Supports normal cardiac function • Decrease in number of normal pacemaker cells in AV node and both bundle branches • Refractory period of the AV node increases • EKG without specific changes with normal aging • Refractory period: the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following excitation

16. Aging Changes with the Heart • Electrical activity • Layers • Arterial • Thickening of the intimal and medial layers • Lipid deposits • Calcification → medial layer→ collagen deposits→ decreased elasticity + “hardening”

17. Aging Changes with the Heart • Autonomic nervous system (is a part of prepheral NS, and affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils, micturition (urination), and sexual arousal. • Decreased responsiveness to beta-adrenergic stimulation • Baroreceptors less efficient • Other aging systems that affect cardiovascular function • Pulmonary • Renal • Baroreceptors (or baroceptors) are sensors located in the blood vessels of several mammals.` They are a type of mechanoreceptor that detects the pressure of blood flowing through them, and can send messages to the central nervous system to increase or decrease total peripheral resistance and cardiac output.

18. LEARNING OUTCOME 2 List focus areas of assessment for cardiovascular patients.

19. History of Cardiovascular Problems • Careful interview is important • Allow patient to share concerns • Gather pertinent information

20. History of Cardiovascular Problems • Comprehensive • Demographic information • Patient’s date of birth • Source of history, if other than the patient • Chief complaint • History of the present illness • Past history • Review of systems • Family history • Social history • Functional health pattern assessment, for nursing planning

21. Complete Review of Systems • Focus for an older patient with cardiovascular problems • Presence or absence of chest pain • Shortness of breath • Syncope • Palpitations • Edema

22. Complete Review of Systems • Focus for an older patient with cardiovascular problems • Nocturnal dyspnea • Nocturia • Pain in the extremities • Cough • Fatigue

23. Women’s Symptoms are Often Vague and Often Not Reported • Symptoms include • Sleep disturbance • Chest discomfort such as tightness, squeezing, fullness, or pressure that can come and go • Discomfort in the back, neck, jaw, or stomach • Shortness of breath • Feelings of nausea, light-headedness, or breaking out in a cold sweat

24. LEARNING OUTCOME 3 Relate physiological concepts to the diagnosis and management of common cardiovascular conditions, including hypertension, angina, heart failure, and peripheral vascular disease.

25. Heart Disease is the Number-One Cause of Death for Older People • Develops slowly • Takes years to develop

26. Hypertension • Major risk factor for other cardiovascular conditions • No symptoms of its own

27. Statistics • 43 million Americans (24%) have hypertension • Only 69% of people with elevated BP are aware of it

28. Physiological Mechanisms of Hypertension • Increased systemic vascular resistance → decrease cardiac output • Decrease stroke volume • Stroke volume: The amount of blood pumped by the left ventricle of the heart in one contraction.

29. Causes • Primary hypertension • No known cause • Secondary hypertension • 5% to 10% of cases • Specific causes • Renal artery stenosis • Adrenal dysfunction

30. Untreated Hypertension • Left ventricular hypertrophy and increased risk of CAD • Proteinuria: High blood pressure can cause damage to the kidneys, which may be reflected as an increase in the amount of protein present in the urine. • Eye • Stroke

31. Hypotension • Orthostatic hypotension • BP check while lying, sitting, standing • Medications with hypotensive effect • Alpha-adrenergic blockers • Centrally acting antihypertensive agents • Psychotropic drugs and tranquilizers • High-dose antibiotics • Nonsteroidal anti-inflammatory drugs (NSAIDs)

32. Hyperlipidemia • Lipid classifications • High-density lipoproteins (HDLs) • Low-density lipoproteins (LDLs) • Triglycerides • Risk factors • Elevated cholesterol • Atherosclerosis • Peripheral artery disease • Abdominal aortic aneurysm • Diabetes mellitus

33. Hyperlipidemia • Medication management • HMG CoA reductase inhibitors (statins) lower LDL cholesterol • Anti-inflammatory • Antithrombotic • Protect intravascular plaque stability • Bile acid sequestrants • Attach to bile in the gut and prevent returns to liver • HMG CoA reductase is a liver enzyme that is responsible for producing cholesterol

34. Hyperlipidemia • Medication management • Fibrates • Reduce triglycerides • Nicotinic acid • Lowers LDL and triglycerides • Raises HDL

35. Chest Pain • Myocardium deprived of blood supply → ischemia→ pain + loss of function • Chronic pain = angina • Other causes • Aortic stenosis • Pericarditis • GI problems • Heartburn, acid reflux, or ulcers

36. Chest Pain • Other causes • Pulmonary problems • Pulmonary embolus, pneumonia, or pleural effusions • Musculoskeletal • Herpes zoster (shingles): is a nerve infection caused by the chicken-pox virus

37. Angina • Ischemic heart disease • Inadequate oxygen supply • Stressed cardiac cells → arrhythmias → ineffective contractions • Categories • Supply: decreased blood flow to the myocardium • Demand: increased demand for oxygen to myocardium

38. Angina • Stable angina: relieved by rest • Management: sublingual nitroglycerin • Unstable angina: not relieved with rest of medication • Progression to MI • Prinzmetal’s angina: chest pain at rest • Transient coronary artery contractions, unrelieved by nitroglycerin

39. Myocardial Infarction • Cell death → loss of cell contraction → decreased heart function • Damage determined by size and location • LAD: The left anterior descending coronary artery • RCA • Circumflex

40. Diagnosis of an MI • History • Atypical symptoms in older adults • Complaints of MI symptoms different in older women • May include nausea or vomiting • Weakness • Shortness of breath • Diaphoresis • Confusion • Syncope

41. Diagnosis of an MI • Physical assessment: may be unremarkable • Laboratory • CK (creatine kinase) and CK-MB (CK-m band) • Tropinin • LDH (lactic dehydrogen)

42. Diagnosis of an MI • EKG analysis • ST segment elevation • Widened QRS complexes • Q wave presence • Other examinations • Hemodynamic monitoring • Echocardiography

43. Diagnosis of an MI • Complications of MI • Arrhythmias • Blockages of electrical conduction • Heart failure • Ventricle aneurysms • Pericarditis

44. Diagnosis of an MI • Medication management • Anti clot agents • Pain control • Beta-blockers • Calcium channel blockers • Angiotension-converting enzyme inhibitors

45. Diagnosis of an MI • Medication management • ASA (aspirin) • Antiarrhythmic drugs • Other management • Coronary angioplasty • Oxygen

46. Valvular Heart Disease • Two categories • Stenosis • Incompetence, regurgitation, or insufficiency

47. Valvular Heart Disease • Aortic stenosis • Most common valve disorder in the older adult • Major cause is calcified degenerative stenosis • Can lead to CHF, angina, alterations in BP, and arrhythmias • Risk factors • Hyperlipidemia • Diabetes • Hypertension

48. Valvular Heart Disease • Aortic stenosis • Diagnosis • History: progressive shortness of breath • Physical examination for murmur • Treatment • Mechanical intervention • Surgical intervention

49. Congestive Heart Failure • Statistics • 33% of hospitalizations are for CHF • Men and women develop equally • Incidence for women has increased • Men develop after an MI or longstanding hypertension • Incidence of mortality is declining • Long-term prognosis is not good

50. Congestive Heart Failure • Pathophysiology • Loss of contractility of the myocardium → inadequate cardiac output → activity intolerance • Frank-Starling Law • Overstretching → decreased force of contraction • Starling's law states that the greater the volume of blood entering the heart during diastole (end-diastolic volume), the greater the volume of blood ejected during systolic contraction (stroke volume) and vice-versa.