Guide — Med-Surg
Heart Failure Basics
Heart failure (HF) is a clinical syndrome in which the heart cannot pump enough blood to meet the body's needs. It is one of the most common reasons for hospitalization in adults. This guide covers the two primary types, ejection fraction categories, fluid overload, and nursing management priorities.
10 min read · Med-Surg
Educational use only. Heart failure management requires individualized provider orders and ongoing clinical assessment. Medication titration, fluid targets, and diet modifications are individualized. Always follow facility protocols and provider orders. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
Overview
Heart failure occurs when the myocardium is unable to generate sufficient cardiac output to meet metabolic demands, or can only do so at elevated filling pressures. The result is a cascade of compensatory mechanisms — neurohormonal activation, ventricular remodeling, and fluid retention — that temporarily maintain perfusion but ultimately accelerate disease progression.
HF is classified by the side of the heart primarily affected (left vs right) and by ejection fraction category (reduced EF vs preserved EF). Both classifications carry important implications for treatment and nursing care.
Key HF statistics for clinical context:
- Affects approximately 6 million adults in the United States
- Leading cause of hospitalization in adults over 65
- 30-day readmission rate is approximately 20–25%
- Daily weight monitoring and dietary adherence are primary drivers of outpatient stability
Pathophysiology
When cardiac output falls, compensatory mechanisms activate to maintain perfusion:
- Sympathetic nervous system activation: Increases heart rate and contractility; causes peripheral vasoconstriction to redirect blood to vital organs. Short-term benefit, long-term harm — increases cardiac workload and promotes remodeling.
- RAAS activation: Renin-angiotensin-aldosterone system promotes sodium and water retention (increasing preload), and causes vasoconstriction (increasing afterload). Over time, worsens HF.
- Ventricular remodeling: The heart enlarges and changes shape in response to chronic pressure or volume overload. Initially compensatory, but ultimately reduces efficiency and worsens prognosis.
- BNP release: B-type natriuretic peptide is released by stretched ventricular myocytes; acts as a counter-regulatory vasodilator and natriuretic. Serum BNP/NT-proBNP levels are used diagnostically and to monitor HF severity.
Left-Sided vs Right-Sided Heart Failure
| Feature | Left-Sided HF | Right-Sided HF |
|---|---|---|
| Primary problem | Left ventricle fails to pump blood forward into systemic circulation | Right ventricle fails to pump blood forward into pulmonary circulation |
| Fluid backs up into | Pulmonary circulation → pulmonary edema, crackles, dyspnea | Systemic venous circulation → JVD, peripheral edema, ascites |
| Classic symptoms | Dyspnea on exertion, orthopnea, PND, pulmonary crackles, S3 gallop | JVD, dependent pitting edema, hepatomegaly, ascites, weight gain |
| Common causes | CAD, hypertension, MI, valvular disease, cardiomyopathy | Left-sided HF (most common), COPD, pulmonary hypertension, PE |
Most patients develop biventricular failure over time. Left-sided HF is the most common cause of right-sided HF.
Reduced EF vs Preserved EF
Ejection fraction (EF) — the percentage of blood ejected from the left ventricle with each beat — is used to classify HF and guide treatment selection:
HFrEF — Heart Failure with Reduced Ejection Fraction
EF ≤ 40%. The left ventricle is dilated and weak — systolic dysfunction. Strong evidence base for ACE inhibitors/ARBs/ARNIs, beta-blockers, aldosterone antagonists, and loop diuretics.
HFpEF — Heart Failure with Preserved Ejection Fraction
EF ≥ 50%. The left ventricle is stiff and cannot relax normally — diastolic dysfunction. Pump function is preserved but filling is impaired. Associated with hypertension, obesity, diabetes, and atrial fibrillation.
HFmrEF — Mildly Reduced EF
EF 41–49%. An intermediate category, often shares features of both HFrEF and HFpEF.
Clinical Manifestations
Pulmonary Congestion (Left-Sided)
- Dyspnea on exertion (DOE) — earliest symptom, worsens with disease progression
- Orthopnea — breathlessness when lying flat; patient requires 2+ pillows to sleep
- Paroxysmal nocturnal dyspnea (PND) — sudden awakening with severe dyspnea 1–2 hours after falling asleep
- Bibasilar crackles (rales) — fine crackling sounds from fluid in alveoli
- Frothy, pink-tinged sputum in acute pulmonary edema
- S3 gallop (ventricular filling sound) — highly specific for fluid overload in adults
Systemic Fluid Overload (Right-Sided)
- Jugular venous distension (JVD) — visible when patient is at 45-degree angle
- Dependent pitting edema — 2+ to 4+ pitting in ankles, legs; sacral edema in bedridden patients
- Hepatomegaly and right upper quadrant tenderness
- Ascites in advanced disease
- Rapid weight gain (1–2 lb/day from fluid retention)
- Nocturia — fluid redistributes from dependent areas when supine at night
Assessment Findings
Vital Signs
- Tachycardia (compensatory to maintain CO with reduced SV)
- Hypertension (common in HFpEF) or hypotension (late decompensated HF)
- Tachypnea with decreased SpO₂ in pulmonary congestion
- Pulsus alternans (alternating strong/weak pulses) in severe HF
Diagnostic Markers
- BNP > 100 pg/mL or NT-proBNP > 300 pg/mL — elevated in HF; correlates with severity
- Chest X-ray: cardiomegaly, pulmonary vascular congestion, Kerley B lines, pleural effusions
- Echocardiogram: confirms EF, identifies structural abnormalities, guides therapy
- Electrolytes: hyponatremia common; hypokalemia risk with loop diuretics
- Renal function: BUN/creatinine rise with reduced perfusion or diuresis
Nursing Priorities
Fluid Balance Monitoring
- Daily weights: Same scale, same time, same clothing. Weight gain > 2 lb in 24 hours or > 5 lb in one week warrants provider notification.
- Strict intake and output monitoring; fluid restriction as ordered (often 1.5–2 L/day)
- Monitor for signs of worsening congestion: increasing dyspnea, new crackles, rising weight, increasing edema
- Monitor for over-diuresis: hypotension, tachycardia, rising BUN/creatinine, hypokalemia, hyponatremia
Medication Monitoring
- Loop diuretics (furosemide): Monitor urine output, potassium, BUN/creatinine. Hold for SBP < 90 or low urine output per protocol.
- ACE inhibitors/ARBs: Monitor BP, potassium, and renal function. Hold for significant hypotension or hyperkalemia.
- Beta-blockers: Monitor HR and BP. Do not abruptly discontinue. Hold for HR < 60 or SBP < 90 per protocol.
- Digoxin: Narrow therapeutic window (0.5–0.9 ng/mL for HF). Toxicity symptoms: nausea, bradycardia, visual disturbances, dysrhythmias.
Positioning and Oxygenation
- Semi-Fowler's or high-Fowler's position to reduce preload and relieve dyspnea
- Supplemental oxygen to maintain SpO₂ ≥ 94%
- Continuous cardiac monitoring for dysrhythmias
Patient Education
- Daily weights: Weigh every morning after urinating, before eating. Call provider for gain > 2 lb in a day or > 5 lb in a week.
- Sodium restriction: Most patients are limited to < 2 g sodium per day. Teach label reading — sodium hides in canned soups, processed foods, and restaurant meals.
- Fluid restriction: Follow prescribed limits (typically 1.5–2 L/day). Ice chips count as fluid.
- Medication adherence: Never stop beta-blockers or ACE inhibitors without provider guidance. Missed diuretic doses can cause rapid fluid accumulation.
- Activity: Balanced rest and activity. Cardiac rehab is beneficial for eligible patients. Pace activities and rest before and after exertion.
- When to call: Increased dyspnea at rest, new or worsening leg swelling, weight gain, inability to sleep flat, decreased urine output.
NCLEX Pearls
- Left HF → fluid backs up into the lungs (pulmonary crackles, dyspnea, orthopnea)
- Right HF → fluid backs up into the body (JVD, peripheral edema, ascites)
- S3 gallop in an adult = fluid overload until proven otherwise
- Daily weight is the most important intervention for HF outpatient management
- Orthopnea and PND are classic left-sided HF symptoms
- Priority action for dyspnea in HF: position upright, apply O₂, notify provider
- Loop diuretics (furosemide) are first-line for fluid removal — monitor K⁺
- Hold beta-blockers for HR < 60; hold ACE inhibitors for severe hypotension or rising creatinine
- BNP > 100 supports HF diagnosis; correlates with severity and guides treatment
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with Academy of Medical-Surgical Nurses (AMSN) · Current medical-surgical nursing standards. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →