III CARDIOVASCULAR HEART FAILURE Heart failure = the heart cannot pump an adequate supply of blood to meet the demands of the body. Cardiac output falls, leading to decreased tissue perfusion. - the kidneys shut down, decreased perfusion to the brain (decrease LOC, confusion, tired) - heart failure itself is not a disease, it is secondary to other diseases (i.e., CAD, hypertension) - important labs to monitor for heart failure BNP, creatinine .Atherosclerosis (blockage, decreased tissue perfusion) and hypertension (increased after load, vasoconstriction, increased muscle size hypertrophy) are the most common causes of heart failure. PHYSIOLOGY AND REVIEW 1. Cardiac output the amount of blood ejected from the left ventricle each minute. (5 L/min) - cardiac output= stroke volume x heart rate - any changes in cardiac output lead to decreased ventricular function and resultant manifestations of heart failure 2. 3. stroke volumethe amount of blood ejected with each heartbeat. (70 mL) Preloadvolume of blood in the ventricle at the end of diastole. (Frank-Starling law which states that the force of the ventricle is related to the stretch in the muscle fibers.) - the heart can't pump what it doesn't get - increased preload = increased stretch 4. 5. After loadforce that the ventricle must exert to eject blood into circulation - vasoconstriction hypertension Contractilityability of the muscle fibers to shorten during systole. Contractility is necessary to overcome after load and eject blood during systole. Poor contractility affects CO. Ejection Fraction percentage of the end-diastolic volume in the ventricle an indication of the amount of blood that was ejected and also tells the contractile ability of the ventricle. - how strong or weak the heart is - an echocardiogram can give a preliminary ejection fraction (not accurate; can't base diagnosis on this number) - less than 18% ejection fraction candidate for heart transplant
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Common Causes of Heart Failure: 1) Hypertension 2) Coronary artery disease (atherosclerosis) 3) Cardiomyopathy(CM) heart muscle disease that can affect structural and functional ability of myocardium a. Dilated CM enlargement of the heart's chambers i. Inflammation causes rapid degeneration of myocardial fibers that cause ventricular dilation and decreased contractile function (alcohol-induced, genetic, hypertension) b. Hypertrophic CM thickening of heart muscle and ineffective pump (hypertension, genetic) c. Restrictive CM least common; impairs diastolic filling and stretch (idiopathic, neoplastic tumors, ventricular thrombosis 4) Substance abuse 5) Valvular disease 6) Congenital defects 7) Cardiac infections and inflammations (myocarditis) increased oxygen and metabolic demand
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****Considerations for older adults: The use of certain drugs can also lead to heart failure (HF), especially in older adults. Long-term use of NSAIDS such as Motrin cause sodium and water retention. PATHOPHYSIOLOGY Types of Heart Failure: 1) Left-sided heart failure: - Because the 2 ventricles of the heart represent 2 separate pumping systems, it is possible for one to fail by itself for a short period. - inability of LV to fill or pump sufficient blood to meet tissues need for oxygen and nutrients - RV has to compensate for LV failure, causing pooling of blood into the pulmonary system - Causes: Long term uncontrolled hypertension, coronary artery disease, valvular disease involving the mitral or aortic valve. May be acute or chronic; and can be further divided into systolic heart failure and diastolic heart failure. Chest x rays can show caridomegaly (enlarged heart) Key features of Left sided heart failure: (pulmonary congestion) Fatigue earliest symptom -orthopnea -frothy, pink sputum Weakness -tachypnea -S3 and S4 (gallop) Angina -pallor -Pulsus alternus Confusion, restlessness -dry, hacking cough Dizziness -dyspnea Tachycardia, palpitations -oliguria during day a) Systolic Heart Failure: (forward failure) a. Results when the heart is unable to contract forcefully enough during systole to eject adequate amounts of blood into the circulation. b. Ejection Fraction: drops below 40%. As the EF decreased, tissue perfusion diminishes and blood accumulates in the pulmonary vessels. c. Clinical signs will include symptoms of inadequate tissue perfusion or pulmonary and systemic congestion. d. Caused by MI, increased afterload, hypertension b) Diastolic Heart Failure: (backward failure) a. Occurs when the left ventricle is unable to relax adequately during diastole b. Symptoms are similar to that of Systolic heart failure c. Impaired filling of the ventricle causes blood to back into the atria d. Causes of diastolic heart failure: usually caused by chronic hypertension or aortic stenosis c) Mixed Systolic-Diastolic Failure: a. Usually seen with dilated cardiomegaly 2) Right-sided heart failure: a. May be caused by left ventricular failure, right ventricular MI, or pulmonary hypertension. b. Pressure increases, organs get bigger (edema)
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Key features of Right-sided heart failure: - JVD (backup of fluid from right side of heart) - Enlarged liver and spleen - Anorexia and nausea - Dependent edema (legs and sacrum) - Distended abdomen - Swollen hands and fingers - Polyuria at night - Weight gain - Need protein in meals - Small frequent meals - Assess for fluid retention of bedridden patients in the sacrum area; in the feet and legs for ambulatory patients CHF classification system: between activity level and symptoms Class I/II less severe Class III/IV indicate severe limitations - classifications are helpful for case management and discharge planning Compensatory mechanisms--when cardiac output is insufficient to meet the demands of the body compensatory mechanisms operate to improve cardiac output. These mechanisms may initially increase cardiac output, they eventually have a damaging effect on pump function. Compensatory mechanisms include: 1. SNS: tissue hypoxia causes increased release of cathecholamines. This causes an increase in heart rate and blood pressure from vasoconstriction. Initially there is a compensatory rise in CO (cardiac output) but this does not last. If the HR is too fast, diastolic filling time is limited and CO may start to decline. An increase in HR also increases O2 demand. 2. Renin- Angiotensin System Activation: Sodium and water retention. This increases preload and afterload. 3. Myocardial hypertrophy: The walls of the heart thicken to provide more muscle mass, which results in more forceful contractions. These mechanisms help to improve CO for awhile but then cardiac decompensation occurs, resulting in: Increased HR shortens diastolic filling time Decreased coronary artery perfusion Ischemia occurs and compromises CO Ventricular dilation and hypertrophy fail d/t continued stretching Renin-angiotensin mechanism results in increased preload and afterload This weakens the heart even more Assessment: 1) History Obtain medical history: a) Left sided heart failure: (may present as pulmonary edema pink, frothy sputum, cyanosis, agitation) i. assess activity tolerance: can the patient climb stairs w/out SOB or fatigue (earliest symptom of heart failure) ii. assess chest pain, palpitations iii. cough early sign of HF (is the patient on Ace-Inhibitors?) iv. assess orthopnea (how many pillows do they sleep on at night) v. assess for paroxysmal nocturnal dyspnea awakening after about 2 to 5 hours of sleep with a feeling of breathlessness. Fluid that accumulated in the dependent extremities during the day begins
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to be reabsorbed into the circulating blood volume when the person lies down. Because the impaired left ventricle eject cannot the increased circulating volume, the pressure in the pulmonary circulation increases, causing further shifting of fluid into the alveoli. The fluid filled alveoli cannot exchange oxygen and CO2. vi. weight gain? vii. do they awaken SOB? b) Right-sided heart failure: i. Assess for edema to the lower legs, thighs, abdominal wall. Patient may state noticing that shoes feel tighter or that shoes and socks leave indentations on their swollen feet. Ask about weight gain. An adult may retain 4 to 7 liters of fluid before pitting edema occurs. ii. The patient may complain of nausea and anorexia. iii. Ask about polyuria: fluid in the peripheral tissue is mobilized and excreted, causes frequent awakening at night to urinate. iv. nutritional history: salt intake v. teach early signs and symptoms vi. teach the importance of weighing daily and reporting weight gain of more than 3 pounds in one day or 5 or more pounds in 1 week vii. obtain their nutritional history
3) Physical Assessment Left-sided heart failure: a) assess for target organ damage: urine output/labs b) vital signs and respiratory rate c) orientation d) crackles and wheezes e) S3 and S4 f) Strict I and O's g) Daily weights Right-sided heart failure: a) JVD b) Ascites c) Dependent edema: ambulatory patient- ankles and legs. Bedridden: sacral edema. 4) Perform a psychosocial assessment (fatigue, depression, anxiety, feel like they are drowning?) 5) Laboratory Assessment a) Electolytes: diuretics can cause imbalances. (K+, Na+,creatinine) b) Assess renal function (BUN and creatinine) c) Urinalysis: proteinuria and high specific gravity. d) H & H: determine heart failure that may result from anemia. e) BNP: B-type natriuretic peptide. Secreted in response to increased stretch of the muscle. Normal is less than 100 pg/ml (determines degree of heart failure); after diuresis, level should go down f) Liver function tests (hepatomegaly) look at AST and ALT 6) Radiographic Assessment and other a) CXR (shows size of heart, presence of pleural effusion or pulmonary edema) b) EKG c) Echocardiograph preliminary ejection fraction; heart catheter performed to diagnose heart failure Common Nursing Diagnoses: 1) Impaired gas exchange
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Decreased Cardiac Ouptut (decreased oxygen supply, increased demand) Activity Intolerance (SOB, dyspnea, fatigue) Excess Fluid Volume Acute confusion Anxiety
Interventions for patients with CHF: 1) Ventilation assistance: a. With respiratory difficulty, place patient in high Fowler's position with feet dangling (to decrease venous return by pooling blood in extremity to decrease preload) with pillows under each arm to maximize lung expansion. b. Assess for SOB, activity intolerance c. Rule out MI d. Airway is first priority check pulse ox do they need oxygen? e. Doctor will order chest x ray and echo 2) Diet therapy: aimed at reducing total body sodium and water retention. a. Omit table salt reduce sodium intake to about 2-3 g daily. i. Watch hidden sodium sources- laxatives, cough syrups, salt substitutes (may contain excessive potassium). Consult MD before taking OTC meds. b. Fluid intake may be limited to 2 liters per day. c. WEIGH PATIENT DAILY: SAME SCALE, SAME TIME, BEFORE BREAKFAST PREFERABLY. d. Encourage to eat small, frequent meals e. check BNP f. input and output 3) Activity intolerance: allow frequent periods of rest. 4) Assess respiratory status at least every 4 hours. 5) Assess for edema: 6) Assess mental status (confusion, hypnatremia) PHARMACOLOGY 1) Diurectics: Examples: Lasix, Bumex, thiazides, and potassium sparing. Metabolized in kidney or liver. a. Work to reduce preload by promoting the excretion of sodium and water by the kidneys. b. Nursing considerations: watch potassium levels, monitor urine output, assess lung sounds, JVD, monitor uric acid levels, teach about photosensitivity c. Side effects of diuretics: hypotension, fatigue, hyperkalemia (potassium sparing), hypokalemia (all other diuretics), decreased Na+ d. Decrease workload of heart ACE inhibitors: ("prils") Monitor for hypotension, hypovolemia, hyponatremia, and alterations in renal function. Watch for side effect of dry, hacking cough can confuse CHF. a. Usually 1st choice for treatment of heart failure b. Watch for hyperkalemia c. Side effect: dry, hacking cough d. Increases contractility by decreasing workload ACE II Receptor Blockers: (-sartans) Cozaar for example. Decrease the blood pressure and lower the resistance. Side effects similar to ACE inhibitors: increased potassium, dec BP, and renal dysfunction. a. Decreases afterload b. Other side effects; abdominal pain, headache, dizziness
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Beta Blockers: (-olol's) Side effects: dizziness, dec BP, Dec HR. a. Causes worsened asthma, strenuous activity intolerance, increases blood sugar (teach diabetics to check sugar more often) helps prevent addt'l muscle damage b. Coreg Digoxin: Lanoxin. Increases the force of contraction and slows conduction through the AV node. Improves contractility, increasing left ventricular output. (does not prolong survivability) a. Monitor levels: normal is between 0.5 2.0 ng/ml. b. Look at CHART 30-3. c. Be careful with elderly and with those with renal impairment (toxicity can occur at low or even normal levels) d. Take apical pulse for 1 minute before administration of dig e. Notify MD if pulse is less than 60 f. Give antacids 6 hours before or after med, don't change brands, don't skip dose, don't take extra dose if missed, hypokalmeia can cause dig toxicity (fatigue, nausea, vomiting, yellow or green halo around objects g. Digibind is given to reverse dig toxicity levels will be elevated post treatment, therefore unreliable; serum dig levels will be inaccurate for several days after digibind
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Inotropic agents: (usually given at infusion clinics for end stage HF) a. Dobutamine: increases cardiac contractility (reaction: watch for redness at site, can cause skin to slough off; stop med immediately) b. Primacor: decreases preload and afterload, reducing the workload of the heart. Watch blood pressure with this drug!! Other side effects include GI dysfunction, increased ventricular dysrhythmias, and decreased platelet count. i. Doesn't increase oxygen demand; decreases risk of dysrhythmias c. Natrecor: improves stroke volume and decreases preload and afterload. Side effect: dose related hypotension. i. Given for long standing heart failure ii. Can increase risk of ventricular dysrhythmias Calcium Channel Blockers a. Treats increased BP with Heart failure (procardia, norvasc) b. Causes relaxation c. Intereferes with calcium's role in contraction of heart and blood vessels, causing relaxation d. Side effects: headache, flushing, hypotension e. Grapefruit juice increases effects
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OTHER DEVICES USED TO HELP HEART FAILURE: 1) Heart Transplantation 2) LVAD Left ventricular assistive devices 3) Heart reduction surgery Complications of Heart Failure: 1) Development of Pulmonary Edema: a. An acute event that results from HF. It can occur acutely (MI) or as an exacerbation of HF. Blood backs up into the pulmonary circulation. b. Clinical Manifestations: pink frothy sputum, restlessness, skin turns gray, weak pulse, distended neck veins, c. Medical Management: O2, MSO4, Diuretics, Dobutamine, Milrinone, Natrecor.
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d. Nursing Management: position patient upright (high fowler's) with the legs dangling. This decreases venous return, lowering the output of the right ventricle, and decreasing lung congestion; psychological support. 2) Cardiogenic Shock: heart cannot pump enough blood to supply the amount of oxygen needed by the tissues. ; Arrhythmias
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