Heart Failure

1. Heart Failure Vocational Nursing Summer 2009

2. Stroke volume x HR/min Stroke volume = 60-80% of volume in ventricle at end of diastole Cardiac output

3. preload Amount of blood in left ventricle at end of diastole Determined by compliance of ventricle and amount delivered by the venous system Constriction of venous system causes blood to be delivered faster, increasing preload

4. preload Increased preload ? increased stretch of muscle Think of a bow and arrow; the more you stretch the string, the more forceful the ejection of the arrow

5. preload Thus with more stretching (preload), you get a more forceful contraction, up until a critical point, when the heart is overstretched Again think if you pull the bow and arrow string too far and it breaks; no ejection of the arrow

6. contractility Ability of the heart to contract and the force at which it does so Independent of preload and afterload Affected by natural and externally acquired chemicals

7. afterload Force resisting the contraction of the cardiac muscle fibers End-systolic wall stress Equivalent to aortic back pressure

8. afterload Increased afterload slows build up of pressure in the ventricle When pressure in ventricle is higher than aorta the aortic valve opens Blood to flows out (remember things always go from high to low pressure)

9. Heart rate Remember CO = HR x SV Do the math and see that an increase in HR also increases CO Increased HR increases amount of blood in vasculature ? Stretching of the arteries ? Increased BP

10. Heart rate Increased CO continues to about 140 bpm Diastolic filling time gets too short and Stroke Volume begins to decrease ? Decrease in CO

11. summary Think of a bucket with a faucet filling and a pump and hose draining The faucet = Preload or amount filling heart Pump = Heart contractility (inotropy) Hose = Diameter of hose is Afterload

12. Heart Failure (HF) Formerly known as Congestive Heart Failure Definition Syndrome Heart cannot pump enough blood to meet body�s metabolic needs

13. Heart Failure (HF) Results in Intravascular volume overload Interstitial volume overload Poor tissue perfusion

14. Etiology of Hf Coronary artery disease ? #1 cause Abnormal cardiac muscle function Abnormal left ventricular volume Abnormal left ventricular pressure Abnormal left ventricular filling

15. Coronary artery disease Ischemia ? Myocardial dysfunction ? Hypoxemia and acidosis

16. Abnormal cardiac muscle function Cardiomyopathy ? Cellular necrosis ? Fibrosis ? Decreased contractility MI ? Focal heart muscle necrosis ? Loss of contractility

17. Abnormal left ventricular volume Valvular insufficiency (ineffective closure) ? Difficulty with blood moving forward ? Abnormal backflow into left atrium ? Decreased cardiac output Increased workload of the heart

18. Abnormal left ventricular pressure Hypertension (systemic or pulmonary) ? Increased afterload ? Increased workload of heart ? Compensatory hypertrophy of myocardial muscle fibers ? Increased contractility with decreased filling ability ? Eventually heart fails

19. Abnormal left ventricular filling Mitral/Tricuspid valve stenosis (narrowed) ? Increased force needed to move blood ? Difficulty moving blood forward ? Increased pressure in heart ? Increased cardiac workload

20. HF classifications Left-sided HF Ineffective LV filling or emptying Right-sided HF Ineffective RV filling or emptying Systolic dysfunction Ineffective LV pumping during systole Diastolic dysfunction Ineffective LV relaxation and filling during diastole

21. Left-sided heart failure Traditional term Left side of the heart cannot fill properly or pump enough oxygenated blood to the body

22. Right-sided heart failure Traditional term Right side of the heart cannot fill properly or pump enough de-oxygenated blood to the pulmonary circulation

23. Systolic dysfunction Current term Inability of heart to pump sufficiently due to alteration in ability to contract

24. Diastolic dysfunction Current term Inability of heart to pump sufficiently due to alteration in ability to fill

25. pathophysiology Systolic HF ? decreased volume of blood ejected ? Baroreceptors stimulate sympathetic nervous system ? Increased heart rate and contractility

26. pathophysiology Systolic HF cont�d Continued response ? negative effects Sympathetic response Vasoconstriction of skin, GI tract, kidneys

27. pathophysiology Systolic HF cont�d Vasoconstriction kidneys ? Release of renin ? Formation of angiotensin I Converted by angiotensin-converting enzyme into angiotensin II Potent vasoconstrictor that leads to increased blood pressure and afterload

28. pathophysiology Systolic HF cont�d Angiotensin II ? Stimulates adrenal cortex ? Release of aldosterone ? Sodium and fluid retention ? Stimulation of thirst center and increased fluid consumption

29. pathophysiology Systolic HF cont�d Results in Increased preload Increased afterload Increased stress on left ventricle Increased workload of heart

30. pathophysiology Systolic HF cont�d Attempt at compensation Release of natriuretic peptides Atrial Brain Promote vasodilation and diuresis Effect not strong enough to overcome other mechanisms

31. pathophysiology Systolic HF cont�d Increased workload of heart Decreased contractility Increased end-diastolic volume ? Stretching of myocardial muscle fibers Increased ventricular size Increased stress and workload ? HEART FAILURE

32. pathophysiology Diastolic HF Continued increased workload on heart ? Increased number and size of heart cells Ventricular hypertrophy Altered cellular functioning Resistance to ventricular filling ? Decreased blood in ventricles ? Decreased cardiac output

33. pathophysiology Diastolic HF cont�d Decreased cardiac output ? Neurohormonal responses as with Systolic HF

34. HF Clinical Manifestations Left Sided Heart Failure Congestion in pulmonary system Early Dyspnea Orthopnea Paroxysmal nocturnal dyspnea Fatigue Nonproductive cough

35. HF Clinical Manifestations Left Sided Heart Failure Late Crackles Hemoptysis Displaced PMI Tachycardia Extra heart sounds Cool, pale skin Restlessness and confusion

36. HF Clinical Manifestations Right Sided Heart Failure Congestion in peripheral tissues and viscera Elevated jugular venous distention Right upper quadrant pain Anorexia and nausea Nocturia Weight gain Edema Ascites/Anasarca

37. Acute vs. Chronic HF Chronic Heart failure that develops gradually Subtle early symptoms Symptoms become acute over time Acute Heart failure that occurs suddenly Acute pulmonary edema

38. Pulmonary Edema Treatment Plan Increase gas exchange Oxygen High Fowler�s Reduce volume overload Morphine Diuretics Improve ventricular function Intravenous medications

39. Diagnostic Tests for hf Chest X-ray Increased pulmonary vasculature Interstitial edema Pleural effusion Cardiomegaly Nursing Care Ascertain pregnancy Explain test and need to take & hold breath Remove jewelry

40. Diagnostic Tests for hf Electrocardiogram Hypertrophy Ischemic changes Heart rate and rhythm Nursing Care Explain procedure Electrodes placed Painless Relax, lie still, breathe normally

41. Diagnostic Tests for hf Echocardiogram Left ventricular hypertrophy Left ventricular dilation Abnormal contractility Nursing Care Explain procedure Dark room Lie still Conductive gel and use of transducer

42. Diagnostic Tests for hf Radionuclide ventriculography Ejection fraction less than 40% (systolic HF) Ejection fraction normal � 55%-65% (diastolic HF) Nursing Care Signed consent May eat or be NPO Requires radio-active injection Imaging with computed tomography & ECG match May be done at rest &/or following exercise Increase fluids and void frequently 24-48 hours after

43. B-type Natriuretic Peptide Blood test of neurohormone released by overstretched heart ventricle Used to differentiate HF from other conditions Range based on age, sex, and lab Elevated levels (with symptoms) indicate HF Greater than 100 pg/ml

44. Medical management of hf Objectives Eliminate or reduce cause Reduce cardiac workload Reduce afterload Reduce preload Optimize therapeutic regimens Prevent exacerbations of HF

45. Drug Therapy Angiotensin-converting enzyme inhibitors Prevent conversion of angiotensin I to angiotensin II Decreases vasoconstriction Decreases secretion of aldosterone Reduces sodium and water retention

46. Drug Therapy ACE Inhibitors [~prils] benazepril (Lotensin) captopril (Capoten) enalapril (Vasotec) fosinopril (Monopril) lisinopril (Prinival, Zestril) ramipril (Altace) Side effects Hypotension Hypovolemia Hyperkalemia Dry, persistent cough

47. Drug Therapy Angiotensin II receptor blockers Blocks binding of angiotensin II to receptor sites Inhibits presser effects of renin-angiotensin-aldosterone system ARB valsartan (Diovan) Side effects Hypotension Hyperkalemia

48. Drug Therapy Hydralazine and Isosorbide Dinitrate Alternative to ACEI Nitrates Venous dilation Reduced preload Hydralazine Decreased systemic vascular resistance Decreased LV afterload

49. Drug Therapy Beta-blockers Prescribed with ACEI, diuretics, & digitalis Reduce adverse effects of constant stimulation by sympathetic nervous system Early phase of treatment may worsen symptoms

50. Drug Therapy Beta-blockers carvedilol (Coreg) metopropolol (Lopressor, Toprol) Side effects Dizziness Hypotension Bradycardia

51. Drug Therapy Diuretics Remove excess extracellular fluid Thiazide Inhibit sodium & chloride reabsorption Loop Inhibit sodium & chloride reabsorption Potassium sparing Inhibits sodium reabsorption

52. Drug therapy Thiazide diuretics metolazone (Zaroxolyn) Loop diuretics furosemide (Lasix) bumetanide (Bumex) Potassium sparing diuretics spironolactone (Aldactone) Side effects Electrolyte imbalance Hypotension Hyperuricemia (gout) Ototoxicity

53. Drug therapy Digitalis Increases force of contraction Slows conduction Improves contractility Increases LV output Results in enhanced diuresis Decreased symptoms of systolic HF Improved ability to perform ADLs

54. Drug therapy Digitalis digoxin (Lanoxin) Monitor drug levels Therapeutic level 0.5 to 2.0 ng/mL Side effects Hypokalemia potentiates effects of digoxin Anorexia, nausea, vomiting Fatigue, malaise Changes in heart rate or rhythm Depression Yellow or green halo Snowy vision

55. Fluids & Nutrition Low sodium (250 mg to 3 g/day) diet

56. Fluids & Nutrition Include or avoid high potassium foods Depending on diuretic therapy

57. Fluids & Nutrition Avoid excessive amounts of fluid Moderate to severe HF 1 to 1.5 L/day (4 to 6 cups) Fluid = anything liquid at room temperature

58. Activity Intolerance R/T imbalance between oxygen supply and demand AEB weakness, dizziness, dyspnea during activity and dizziness, dyspnea, RR 28/min, HR 114/min three minutes following activity

59. Nursing Interventions Interventions during hospitalization Monitor VS and Pulse Ox Before During After HR should return to baseline within 3 minutes Gradually increase activity within tolerance Discourage complete bed rest (unless ordered)

60. Nursing interventions Interventions upon discharge Increase duration, frequency and intensity as tolerated Encourage goal of 30-45 minutes of activity daily Avoid extremes of temperature during activity Decrease intensity if unable to talk during activity Wait 2 hours after eating before activity Stop activity if: severe SOB, pain, dizziness

61. Risk for Fluid Volume Overload R/T excess fluid or sodium intake and retention of fluid secondary to HF syndrome

62. Nursing Interventions Administer diuretics in the morning Auscultate lungs Monitor daily weights 1 liter = 1 kg = 2.2 lbs Instruct in low sodium diet Assist with fluid restriction Position to facilitate breathing Prevent skin breakdown

63. Disturbed Sleep Pattern R/T frequent awakenings secondary to HF syndrome AEB difficulty remaining asleep due to paroxysmal nocturnal dyspnea

64. Nursing Interventions Position for optimum respiratory function Limit nighttime fluids Avoid diuretics in evening

65. Powerlessness R/T inability to perform role responsibilities due to frequent hospitalizations and chronic illness AEB states �I can�t do anything I am supposed to be able to do�

66. Nursing Interventions Encourage patient to express concerns and ask questions Provide decision-making opportunities Assist patient to differentiate between factors that can be controlled and those that cannot Advocate for changing hospital policies to promote patient control

67. HF & the Older Adult Normal changes ? increased frequency of HF Increased systolic blood pressure Increased ventricular wall thickness Increased atrial size Increased myocardial fibrosis Atypical signs and symptoms Fatigue Weakness Somnolence (sleepy)

68. HF & the Older Adult Diuretic resistance due to decreased renal function Potential urinary retention in men with diuretics and enlarged prostate Diuretics ? frequency and urgency which may be disturbing to older adults

69. HF & Culturally Diverse Populations African-American high rates of HTN, DM, CAD ? HF More than � of Mexican-Americans have heart disease Heart disease is now #1 killer of Native Americans