Understanding Heart Failure

• Heart Failure is an abnormal condition where the heart can't pump/fill adequately.
• An inadequate cardiac output (CO) will not meet metabolic needs
• Heart Failure is characterized by ventricular dysfunction, reduced exercise tolerance, diminished quality of life, and shortened life expectancy.

Etiology and Pathophysiology

• Primary risk factors are CAD and advancing age.
• Contributing risk factors are hypertension, diabetes, tobacco use, obesity, and high serum cholesterol.

Heart Failure: Causes

• Cardiac defects like myocardial infarction and valve deficiency can cause heart failure.
• Defects outside the hearts are coronary artery disease, pulmonary hypertension and diabetes

Pathophysiology: Systolic vs. Diastolic Failure

• Systolic failure's hallmark is a decrease in left ventricular ejection fraction (EF).
• Systolic failure is caused by impaired contractile function (e.g., MI), inability of heart to pump effectively, hypertension, cardiomyopathy, or mechanical abnormalities.
• Diastolic failure involves the impaired ability of ventricles to relax/fill during diastole, which results in decreased CO.
• Diastolic failure is diagnosed based on pulmonary congestion, pulmonary hypertension, ventricular hypertrophy, and normal EF.
• Diastolic failure is caused by left ventricular hypertrophy, aortic stenosis, or cardiomyopathy.

Types of Heart Failure

• Right-sided symptoms: murmurs, jugular venous distention, edema, weight gain, ascites, anasarca, hepatomegaly, fatigue, anxiety, right upper quadrant pain, anorexia, and nausea.
• Left-sided/Acute Decompensated Heart Failure (ADHF) symptoms: pulses alternans, increased HR, crackles, S3 and S4 sounds, pleural effusion, mental status changes, restlessness, confusion, weakness, dyspnea, shallow respirations, orthopnea, dry cough, and nocturia.

Clinical Manifestations: Acute Decompensated Heart Failure (ADHF)

• Physical findings include orthopnea, dyspnea/tachypnea, accessory muscle use, cool/clammy skin, frothy/blood-tinged sputum, crackles/wheezes/rhonchi, tachycardia, hypotension/hypertension, and late-stage cyanosis.
• Pulmonary edema can be life-threatening manifestation.
• Early signs of pulmonary edema include increased respiratory rate and decreased PaO2.
• Later signs of pulmonary edema include tachypnea and respiratory acidosis.

Clinical Manifestations: Chronic HF

• Chronic HF involves fatigue, dyspnea, orthopnea, paroxysmal nocturnal dyspnea, persistent cough, tachycardia, restlessness, confusion, chest pain, weight changes (anorexia/nausea), and fluid retention.
• Dependent edema is a sign of chronic HF.
• Edema may be pitting.
• Sudden weight gain of >3 lb in 2 days might indicate HF exacerbation.
• Skin presentation may be dusky, cool, and damp.
• Lower extremities may be shiny, swollen, with diminished/absent hair growth or pigment changes.

Complications of Heart Failure

• Pleural effusion, atrial fibrillation, fatal dysrhythmias (sudden cardiac death, ventricular tachycardia), hepatomegaly with RV failure, fibrosis/cirrhosis of liver, and renal insufficiency/failure are all causes of HF

Drug Therapy for Heart Failure

• Inotropic drugs influence myocardial contraction force.
• Chronotropic drugs influence heart rate.
• Dromotropic drugs influence conduction.
• Drugs used to treat heart muscle failure include ACE inhibitors, Angiotensin II receptor blockers, Beta blockers, Aldosterone antagonists, B-type natriuretic peptides, Phosphodiesterase inhibitors, Cardiac glycosides, Loop Diuretics, and miscellaneous drugs.

ACE Inhibitors

• ACE inhibitors prevent sodium and water reabsorption by inhibiting aldosterone secretion.
• Diuresis results in decreased preload, blood volume, blood return to the heart, and heart work.
• Lisinopril, enalapril, fosinopril, captopril, quinapril, ramipril, trandolapril, and perindopril are all ACE inhibitors.
• It used for: Hypertension, Heart Failure, Acute MI

Angiotensin II Receptor Blockers (ARBs)

• ARBs are potent vasodilators that reduce systemic vascular resistance.
• ARBs can be used with diuretics to treat hypertension or heart failure.
• Examples: valsartan (Diovan), candesartan (Atacand), losartan (Cozaar)
• ARBs side effects are URI and hyperkalemia.

Beta Blockers

• Beta blockers reduce or block sympathetic nervous system stimulation to the heart and its conduction system.
• Reduced heart rate, delayed AV node conduction, reduced myocardial contractility, and decreased automaticity result from the use of beta blockers
• Metoprolol and carvedilol (Coreg) are beta blockers.
• Side effects include impotence and mental depression.

Aldosterone Antagonists

• Mostly used in severe stages
• Spironolactone (Aldactone) acts as a potassium-sparing diuretic and aldosterone antagonist, reducing heart failure symptoms.
• Eplerenone (Inspra) is a selective aldosterone blocker.

B-type Natiuretic Peptides

• B-type Natiuretic Peptides treat life threatening heart failure.
• Vasodilating effects occur on arteries and veins.
• They Increase cardiac output indirectly and suppress the renin-angiotensin system/cause diuresis.
• Nesiritide (Natrecor) is the only drug in its class, used in severe, life-threatening heart failure.
• Adverse effects include hypotension, dysrhythmia, headache, and abdominal pain.

Phosphodiesterase Inhibitors

• Phosphodiesterase inhibitors work by inhibiting the enzyme phosphodiesterase.
• Positive inotropic response (increased force of heart contraction) and vasodilation result.
• They are used for short-term management of heart failure in ICU settings.
• They are given when patients do not respond to digoxin, diuretics, and/or vasodilators.
• Milrinone (Primacor) is an example.

Phosphodiesterase Inhibitors: Adverse Effects

• Milrinone's adverse effects include ventricular dysrhythmias, hypotension, angina, hypokalemia, tremor, and thrombocytopenia.

Cardiac Glycosides

• This one of the oldest groups of drugs.
• Cardiac Glycosides are not first-line treatments.
• Originally obtained from Digitalis plant, foxglove.
• They cause a decrease in venous BP and vein engorgement and increases coronary circulation and diuresis.
• They are indicated for heart failure, supraventricular dysrhythmias, atrial fibrillation/flutter.

Digoxin

• Digoxin slows conduction at the SA & AV node and used to slow the rate of atrial fibrillation/flutter.
• It is admininstered PO or IV with a with a long half life and duration of action
• Adverse effect: Cardiac arrhythmias, Yellow halos
• Digoxin Immune Fab (Digibind) is the antidote

Digoxin Cardiac Glycosides: Adverse Effects

• Digoxin has a narrow therapeutic window(0.5-2ng/mL), so both drug and electrolyte levels must be monitored.
• Low potassium levels increase its toxicity.
• Cardiovascular side effects include dysrhythmias (bradycardia or tachycardia).
• CNS side effects include headaches, fatigue, confusion, and convulsions.
• Eye side effects include colored vision and flickering lights.
• GI side effects include anorexia, nausea, vomiting, and diarrhea.

Digoxin Toxicity

• Digoxin immune Fab (Digibind) therapy is the antidote for digoxin toxicity.
• Conditions that predispose patients to Dig toxicity are hypokalemia, use of cardiac pacemaker, hepatic dysfunction, hypercalcemia, dysrhythmias, and advanced age.

Loop Diuretics

• Furosemide, torsemide, and bumetanide are loop diuretics.
• Loop diuretics manage edema associated with HF.
• They decrease plasma volume by promoting excretion of fluid, sodium, and potassium.
• Loop diuretics work well with decreased kidney function.
• They Cause decreases in Systemic Vascular Resistance, Pulmonary Vascular Resistance, Blood Pressure, Central Venous Pressure, and Left ventricular end diastolic pressure

Miscellaneous Drugs to Treat Heart Failure

• Hydralazine/isosorbide dinitrate (BiDil) was the first drug approved for a specific ethnic group, namely African Americans.
• Dobutamine is a Beta₁-selective vasoactive adrenergic drug.
• Structurally similar to dopamine

Heart Failure Drugs: Nursing Implications

• For nesiritide, milrinone, this drugs are administered via infusion pump.
• Should be monitored I&O, heart rate and rhythm, BP, daily weights, respirations

Heart Failure Drugs: Nursing Implications

• Assess clinical parameters, weight, I&O measures, ECG, and serum labs.
• Serum labs should include labs for: potassium, sodium, magnesium, calcium, renal, and liver function studies
• Count apical pulse for 1 full minute before giving any dose that influences HR.
• For apical pulse less than 60 or greater than 100 beats/minute, hold the dose and notify the prescriber.
• Hold dose and report if they experience visual disturbances (blurred vision, seeing green or yellow halos around objects)
• Avoid giving digoxin with high-fiber foods (fiber binds with digitalis).
• Patients should immediately report a weight gain of 2 or more pounds in 1 day or 5 or more pounds in 1 week.
• Monitor for therapeutic effects like increased urinary output, decreased edema/shortness of breath/dyspnea/crackles/fatigue, resolution of paroxysmal nocturnal dyspnea, and improved peripheral pulses/skin color/temperature.
• Monitor for adverse effects

SDOH

• SDOH factors associated with higher readmissions include the county in which the hospital is located, disability status, race, ethnicity, insurance, and income inequality.
• Patients with HF who are food insecure, struggle with transportation, and have less access to medications, education, and health services have significantly poorer health outcomes.
• SDOH influence an individual's physical and mental well-being and how they perceive/experience care.