Heart failure (HF) is a clinical syndrome in which the heart cannot pump enough blood to meet the body's needs, or can do so only at elevated filling pressures. It results from structural or functional impairment of ventricular filling or ejection.
Common causes: coronary artery disease and myocardial infarction, hypertension, valvular heart disease, cardiomyopathy, diabetes, dysrhythmias, and toxins (e.g., alcohol, some chemotherapy agents).
Compensatory mechanisms — helpful short term, harmful long term
- Sympathetic nervous system activation → ↑heart rate and contractility, vasoconstriction
- Renin–angiotensin–aldosterone system (RAAS) → sodium and water retention, vasoconstriction
- Ventricular remodeling → dilation and hypertrophy that further weaken the heart
Most HF drugs work by blocking these mechanisms.
Classification by left ventricular ejection fraction (LVEF)
| Type | LVEF |
|---|
| HF with reduced EF (HFrEF) | ≤ 40% |
| HF with mildly reduced EF (HFmrEF) | 41–49% |
| HF with preserved EF (HFpEF) | ≥ 50% |
| HF with improved EF (HFimpEF) | Previous LVEF ≤ 40%, now > 40% |
Left- vs. right-sided failure
| Left-sided HF — "backs up into the lungs" | Right-sided HF — "backs up into the body" |
|---|
| Dyspnea, orthopnea, paroxysmal nocturnal dyspnea | Jugular venous distension (JVD) |
| Crackles at lung bases | Dependent peripheral edema |
| Cough, pink frothy sputum (pulmonary edema) | Weight gain, ascites, hepatomegaly |
| S₃ gallop, tachycardia | Anorexia, nausea (GI congestion) |
| Fatigue, confusion, oliguria (low output) | |
The most common cause of right-sided HF is left-sided HF.
Acute pulmonary edema is a life-threatening form of left-sided failure: fluid moves from pulmonary capillaries into alveoli, causing severe dyspnea, anxiety, tachypnea, crackles, pink frothy sputum, and hypoxemia.
Staging and functional class
| ACC/AHA Stage (disease progression) | NYHA Class (symptoms/function) |
|---|
| A — At risk (e.g., hypertension, diabetes), no structural disease | I — No limitation of physical activity |
| B — Pre-HF: structural disease, no symptoms | II — Slight limitation; comfortable at rest, ordinary activity causes symptoms |
| C — Structural disease with current or past symptoms | III — Marked limitation; less-than-ordinary activity causes symptoms |
| D — Advanced HF requiring specialized interventions | IV — Symptoms at rest |
Stages move in one direction only; NYHA class can improve with treatment.
Focused assessment
- Respiratory: rate, effort, SpO₂, crackles, orthopnea (number of pillows needed)
- Cardiovascular: heart rate and rhythm, blood pressure, S₃, JVD, capillary refill
- Fluid status: daily weight, intake and output, edema grade
- Mental status, activity tolerance, urine output
| Test | Key finding |
|---|
| Echocardiogram | Measures LVEF, wall motion, valve function — key test to classify HF |
| BNP / NT-proBNP | Elevated in HF; helps distinguish cardiac from pulmonary causes of dyspnea. BNP < 100 pg/mL or NT-proBNP < 300 pg/mL makes acute HF unlikely. Sacubitril raises BNP (not NT-proBNP), so NT-proBNP is used for clients on an ARNI. Levels are lower in obesity |
| Chest X-ray | Cardiomegaly, pulmonary congestion, pleural effusion |
| ECG | Dysrhythmias (e.g., atrial fibrillation), ischemia, hypertrophy |
| Electrolytes, BUN/creatinine | Baseline and during diuretic/RAAS therapy (potassium, sodium, kidney function) |
| ABG / pulse oximetry | Hypoxemia in pulmonary edema |
Guideline-directed medical therapy (GDMT) for HFrEF — the "four pillars"
| Drug class | Examples | Key nursing points |
|---|
| RAAS inhibitor: ARNI (preferred), or ACE inhibitor, or ARB | sacubitril/valsartan; lisinopril, enalapril; losartan | Hypotension, ↑potassium, ↑creatinine. ACE inhibitors: dry cough, angioedema. Do not combine ARNI with an ACE inhibitor (36-hour washout); ARNI is contraindicated with any history of angioedema. Contraindicated in pregnancy |
| Beta blocker (evidence-based) | carvedilol, metoprolol succinate, bisoprolol | Start low, increase slowly. Fatigue may temporarily worsen at first. Check apical pulse and BP; do not stop abruptly |
| Mineralocorticoid receptor antagonist (MRA) | spironolactone, eplerenone | Hyperkalemia; monitor potassium and kidney function. Not started if K⁺ ≥ 5.0 mEq/L or eGFR ≤ 30 mL/min/1.73 m². Spironolactone: gynecomastia |
| SGLT2 inhibitor | dapagliflozin, empagliflozin | Benefits with or without diabetes. Genital yeast infections, UTI, volume depletion. Risk of euglycemic DKA — hold before scheduled surgery (at least 3 days) and during acute illness or fasting |
HFpEF and HFmrEF: diuretics for congestion, control of blood pressure, atrial fibrillation, and other comorbidities, and an SGLT2 inhibitor. The full four-pillar evidence applies to HFrEF.
Symptom relief and other therapies
- Loop diuretics (furosemide) — relieve congestion; do not reduce mortality. Monitor for hypokalemia, hypomagnesemia, hypotension, dehydration. Give IV doses slowly per protocol — rapid high doses can cause ototoxicity
- Hydralazine + isosorbide dinitrate — added for self-identified Black clients with NYHA III–IV HFrEF, or used when RAAS inhibitors cannot be tolerated. Watch for headache and hypotension
- Digoxin — may reduce symptoms and hospitalizations in selected clients; a low serum level (about 0.5–0.9 ng/mL) is commonly targeted in HF
- Devices: ICD for LVEF ≤ 35% with NYHA II–III despite at least 3 months of GDMT; CRT for LVEF ≤ 35% with a wide QRS (especially LBBB, QRS ≥ 150 ms)
- Advanced HF: mechanical circulatory support, transplant, palliative care
Acute decompensated HF / pulmonary edema
- Upright positioning, oxygen, IV loop diuretic (reduces preload and pulmonary congestion)
- Vasodilators (e.g., nitroglycerin) if blood pressure allows — do not give nitrates within 24–48 hours of a PDE-5 inhibitor (sildenafil, tadalafil); hold for systolic BP < 90 mmHg or per order
- Noninvasive ventilation for respiratory distress; inotropes for low-output states
- Morphine is no longer routinely recommended; give only if ordered and monitor for respiratory depression
Listed in priority order.
- Oxygenation (pulmonary edema)
- High-Fowler's position with legs dependent — reduces venous return (preload) and eases breathing
- Administer oxygen to the ordered SpO₂ target when the client is hypoxemic; monitor SpO₂, respiratory status, and lung sounds
- Prepare for IV furosemide; insert or maintain IV access
- Fluid balance
- Daily weight — same time, same scale, same clothing (best indicator of fluid status)
- Strict intake and output, sodium and fluid restriction as ordered
- Monitor potassium, sodium, creatinine
- Medication safety
- Before beta blockers and digoxin: check apical pulse for 1 full minute; hold and notify per parameters (commonly apical pulse < 60/min for digoxin)
- Digoxin toxicity: early signs are anorexia, nausea, vomiting; later bradycardia, dysrhythmias, visual disturbances (yellow-green halos). Risk increases with hypokalemia, hypomagnesemia, hypercalcemia, and reduced kidney function
- Loop diuretics: monitor for hypokalemia — muscle weakness, leg cramps, dysrhythmias
- ACE inhibitors/ARNI/MRA: monitor BP and potassium
- Activity
- Balance activity and rest; progress gradually; cardiac rehabilitation when stable
- Stop activity and rest if dyspnea, chest pain, or dizziness occurs
- Anxiety
- Stay with the client, speak calmly, explain procedures; anxiety increases oxygen demand
- Skin — edematous skin breaks down easily; reposition and inspect
- Weigh yourself every morning after voiding, before breakfast, on the same scale
- Report weight gain of 2–3 lb (about 1 kg) in 1 day or 5 lb (about 2 kg) in 1 week, or increasing swelling, shortness of breath, or need for more pillows to sleep
- Limit sodium; read food labels; follow any fluid restriction
- Avoid salt substitutes and potassium supplements unless prescribed — they contain potassium and can cause dangerous hyperkalemia with ACE inhibitors, ARBs, ARNI, or MRAs
- Take medications exactly as prescribed; do not stop beta blockers suddenly; do not adjust diuretic doses on your own unless following a written plan
- Know side effects: dizziness when standing (change positions slowly), persistent dry cough (ACE inhibitor), signs of low potassium
- Avoid NSAIDs and over-the-counter decongestants, which can worsen HF. Tell every prescriber you have HF — some drugs (e.g., diltiazem or verapamil in HFrEF, pioglitazone) can worsen it
- Stay active within limits; enroll in cardiac rehabilitation if offered
- Stop smoking; limit alcohol, or avoid it completely if HF is alcohol-related
- Stay current on respiratory vaccines (influenza, pneumococcal, COVID-19, and others as recommended in your country)
- Goal of care: control symptoms, maintain function, prevent readmission, and improve quality of life — chronic HF is managed, not cured
| Complication | What to watch for |
|---|
| Acute pulmonary edema | Sudden severe dyspnea, pink frothy sputum, crackles throughout, anxiety, hypoxemia |
| Cardiogenic shock | Hypotension, cool clammy skin, altered mental status, oliguria |
| Dysrhythmias / sudden cardiac death | Atrial fibrillation, ventricular dysrhythmias |
| Electrolyte imbalance | Hypokalemia (diuretics), hyperkalemia (RAAS inhibitors, MRA) |
| Digoxin toxicity | GI symptoms, bradycardia, visual changes |
| Thromboembolism | Stroke, pulmonary embolism (especially with atrial fibrillation) |
| Kidney injury | Rising creatinine, decreasing urine output |
- Left HF → lungs (dyspnea, orthopnea, crackles); right HF → body (JVD, edema, weight gain)
- HFrEF = LVEF ≤ 40%; HFpEF = LVEF ≥ 50%
- Daily weight is the best indicator of fluid status; report 2–3 lb/day or 5 lb/week
- Pulmonary edema: high-Fowler's, legs dependent, oxygen, IV loop diuretic
- HFrEF four pillars: ARNI/ACEI/ARB + beta blocker + MRA + SGLT2 inhibitor
- ACE inhibitor → dry cough, angioedema, hyperkalemia
- Beta blocker → fatigue may worsen at first; never stop abruptly
- Loop diuretic → hypokalemia (weakness, dysrhythmias)
- Digoxin toxicity → anorexia, nausea, vomiting first; risk ↑ with hypokalemia
- Stage (A–D) never goes backward; NYHA class (I–IV) can improve
Country Notes
United States
- HF is a major cause of hospital readmission; transitional care, follow-up within about 7 days of discharge, and teach-back education are standard nursing priorities.
- Weight thresholds in client education are usually given in pounds.
Philippines
- Use kilograms in client teaching (about 1 kg in a day or 2 kg in a week).
- Rheumatic heart disease remains an important cause of valvular HF; assess history of rheumatic fever.
- Many common Filipino dishes and condiments (fish sauce, soy sauce, dried and salted fish, instant noodles) are high in sodium — tailor dietary teaching accordingly. Warn that "low-sodium" salt products often contain potassium.