Heart Failure: What the NCLEX Tests

Medical-Surgical · Cardiovascular·Updated 2026-10-27

What it is

Heart failure is a syndrome in which the ventricles cannot fill or eject enough blood to meet the body's needs. Falling cardiac output activates the sympathetic nervous system and the renin-angiotensin-aldosterone system (RAAS), which retain sodium and water and raise afterload. That fluid retention explains most nursing care: daily weights, sodium restriction, diuretics and RAAS blockers. Left-sided failure backs fluid into the lungs; right-sided failure backs fluid into the systemic veins.

What the NCLEX focuses on

Left-sided signs: dyspnea, orthopnea, paroxysmal nocturnal dyspnea, crackles, S3; pink, frothy sputum signals acute pulmonary edema.
Right-sided signs: jugular venous distention, dependent edema, hepatomegaly, ascites and weight gain.
Daily weight is the most reliable indicator of fluid status; a rapid gain is reported before edema is visible.
B-type natriuretic peptide (BNP) rises with ventricular stretch and helps separate heart failure from COPD as the cause of dyspnea.
Loop diuretics (furosemide): monitor urine output, potassium, blood pressure, orthostatic dizziness and tinnitus after a rapid IV dose.
ACE inhibitors, ARBs and spironolactone cause hyperkalemia and hypotension; ACE inhibitors also cause dry cough and angioedema.
Digoxin: count the apical pulse for 1 full minute; nausea, anorexia, visual halos and new dysrhythmias are toxicity signs, and hypokalemia increases toxicity.

Priority nursing actions

In acute pulmonary edema, place the client in high Fowler position with the legs dependent to reduce venous return.
Apply prescribed oxygen and prepare for noninvasive ventilation if hypoxemia persists.
Give the prescribed IV loop diuretic and vasodilator.
Monitor SpO2, lung sounds, blood pressure, hourly urine output and serum potassium.
Weigh daily at the same time on the same scale and maintain the prescribed sodium and fluid limits.

Numbers to know

Value	Normal or target	Why it matters
Potassium	3.5 to 5.0 mEq/L (3.5 to 5.0 mmol/L)	Low with loop diuretics (digoxin toxicity); high with ACE inhibitors, ARBs, spironolactone
Weight gain to report	3 lb (1.4 kg) in 2 days or 5 lb (2.3 kg) in 1 week	Fluid retention before symptoms worsen
Apical pulse before digoxin	Hold and report if below 60/min	Bradycardia and toxicity
BNP	Below 100 pg/mL (100 ng/L)	Higher values support heart failure as the cause of dyspnea
Ejection fraction	Reduced: 40% or less; preserved: 50% or more	Classifies the type of heart failure

Common exam traps

Choosing supine with the legs elevated for pulmonary edema: wrong because it increases venous return and worsens lung congestion.
Choosing IV 0.9% sodium chloride for a low sodium with weight gain and crackles: wrong because the hyponatremia is dilutional; treatment is diuresis and fluid restriction.
Choosing to give digoxin to a client with nausea and yellow-green halos: wrong because these are toxicity signs; hold the dose and report.
Choosing a salt substitute freely: wrong because most contain potassium chloride, dangerous with ACE inhibitors and spironolactone.
Choosing ibuprofen for joint pain: wrong because NSAIDs retain sodium and water and worsen heart failure.

What to teach

Weigh every morning after voiding and before breakfast, on the same scale in similar clothing; record and report gains.
Read labels and limit sodium: avoid canned soups, deli meats, pickles and frozen dinners.
Rise slowly; report dizziness, dry cough, or swelling of the lips or face.
Call 911 for shortness of breath at rest, inability to lie flat, or chest pain.

Client handout: Heart Failure Self-Care (nurse guide and printable patient handout).

Try 2 NCLEX-style questions on this topic

From the NCLEXPace question bank. Pick your answers, then check them inside NCLEXPace.

Question 1 · QID 08772EE3

A client with chronic heart failure calls the clinic and reports gaining 3 lb (1.4 kg) since yesterday. Which additional report requires the nurse to direct the client to emergency care now?

Select the best answer.

A. “I needed two extra pillows to sleep last night.”
B. “My ankles are more swollen than usual.”
C. “I am short of breath sitting still, and I cannot lie flat.”
D. “I missed one dose of my water pill yesterday.”

Question 2 · QID 47634966

A client admitted with acute decompensated heart failure, pulmonary congestion, and peripheral edema is receiving intravenous furosemide. For each finding, indicate whether it requires reporting to the provider or is an expected response.

	Report to the provider	Expected response
Serum potassium 3.1 mEq/L
Urine output 150 mL during the first hour
New ringing in the ears after a rapid intravenous dose
Crackles decreasing at the lung bases
Dizziness on standing with falling blood pressure
Weight decreased by 1 kg since yesterday

See the answers and full rationales

The correct answers, the reasoning for every option and 3,200+ more NCLEX questions are inside NCLEXPace. Create your account, then choose a plan to open them.

Create Account →

More tips on Medical-Surgical

Acute PancreatitisRecognize acute pancreatitis by pain and lipase, give fluids and pain control first, and catch hypocalcemia, shock and respiratory failure.Bowel Obstruction and NG Tube CareTell small from large bowel obstruction, spot strangulation early, and keep a decompression NG tube placed, patent and safe.Acute Kidney Injury vs Chronic Kidney DiseaseClassify AKI as prerenal, intrarenal or postrenal, follow its phases, and compare it with the staged, irreversible course of CKD.

Sources

Harding MM, Kwong J, Hagler D, Reinisch C. Lewis's Medical-Surgical Nursing: Assessment and Management of Clinical Problems. 12th ed. Elsevier; 2023; Chapter: Heart Failure.
Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation. 2022;145(18):e895-e1032.

Practice the NCLEX questions on this topic

3,200+ NCLEX questions with think-like-a-nurse rationales, unfolding case studies and adaptive readiness exams. Start with free practice questions, then choose a plan when you are ready.