Cardiac Nursing Study Notes

Cardiovascular disease is the leading cause of death in the United States, and cardiac conditions represent a major portion of NCLEX clinical questions. This guide covers the essential cardiac nursing content — from acute MI management to dysrhythmia recognition to cardiac medication priorities — organized for exam preparation and clinical practice.

Cardiac Assessment: What to Look For

A systematic cardiac assessment covers:

Heart rate and rhythm: Apical pulse for 60 seconds; note irregularity
Blood pressure: Both arms on initial assessment; >10 mmHg difference suggests subclavian stenosis or aortic coarctation
Heart sounds: S1 (closure of mitral/tricuspid valves), S2 (closure of aortic/pulmonic valves). S3 = volume overload/heart failure. S4 = stiff ventricle (hypertension, hypertrophy)
Peripheral perfusion: Capillary refill (<2 seconds normal), skin temperature, peripheral pulses (0–4+ scale)
JVD (jugular venous distension): Present at 45° = elevated central venous pressure → right-sided heart failure
Edema: Pitting edema graded 1+ to 4+. Bilateral ankle/leg edema = right-sided HF; pulmonary edema = left-sided HF

Acute Coronary Syndrome: STEMI vs NSTEMI

ACS encompasses unstable angina, NSTEMI, and STEMI — all caused by acute reduction in coronary blood flow.

STEMI: ST elevation in 2+ contiguous leads on 12-lead ECG. Complete occlusion. Requires immediate reperfusion (PCI within 90 minutes is goal, thrombolytics if PCI unavailable within 120 min)
NSTEMI: No ST elevation; troponin elevated. Partial occlusion. Managed with antiplatelet therapy, anticoagulation, and urgent cath (within 24–48 hours)
Unstable angina: ACS symptoms, no ST elevation, troponin negative. Same initial management as NSTEMI

Nursing Priorities in Acute MI

12-lead ECG within 10 minutes of chest pain onset
IV access × 2, oxygen if SpO2 <90%
Aspirin 325 mg (chewed) immediately unless contraindicated
Nitroglycerin SL for ongoing chest pain (hold if SBP <90 or inferior MI with right ventricular involvement)
Continuous cardiac monitoring, defibrillator at bedside
Prepare for emergent PCI or thrombolytics per protocol

Key labs: Troponin I or T (rises 3–6 hours after MI, peaks 12–24 hours, normalizes in 5–14 days). Serial troponins every 3–6 hours × 3. CK-MB rises earlier and normalizes faster — useful for detecting reinfarction.

Heart Failure: Left-Sided vs Right-Sided

Left-sided HF: Fluid backs up into the pulmonary circulation → pulmonary edema. Signs: crackles (rales), orthopnea, PND, S3 gallop, decreased SpO2, pink frothy sputum in acute pulmonary edema
Right-sided HF: Fluid backs up into the systemic venous circulation. Signs: JVD, peripheral edema (bilateral, pitting), hepatomegaly, ascites, weight gain
Most right-sided HF is caused by left-sided HF — the most common cause overall

Heart Failure Key Labs and Diagnostics

BNP: Released by stretched ventricular walls. BNP >100 pg/mL suggests HF; >400 indicates high risk. Differentiates HF from other causes of dyspnea
Chest X-ray: Cardiomegaly, pulmonary vascular congestion, Kerley B lines, pleural effusions
Echo: Ejection fraction (EF). HFrEF = EF <40%; HFpEF = EF ≥50%

Heart Failure Medications

Loop diuretics (furosemide): First-line for fluid removal. Monitor potassium (hypokalemia risk), urine output, daily weights. Ototoxicity with high IV doses
ACE inhibitors (-pril) / ARBs (-sartan): Reduce afterload, decrease cardiac remodeling. Monitor potassium (hyperkalemia), creatinine, BP. ACE inhibitors cause dry cough — switch to ARB
Beta-blockers (carvedilol, metoprolol succinate): Reduce mortality in stable HF. Do NOT start during acute decompensation
Digoxin: Increases contractility, slows HR. Narrow therapeutic window (0.5–2 ng/mL). Toxicity signs: nausea, yellow-green visual halos, bradycardia. Hold if HR <60
Spironolactone: Potassium-sparing diuretic. Used in HFrEF. Monitor potassium closely (hyperkalemia risk)

Dysrhythmias: The Most NCLEX-Tested

Atrial fibrillation: Irregularly irregular rhythm, no distinct P waves. Risk of thrombus → stroke. Anticoagulation (warfarin, DOACs). Rate control with beta-blockers or calcium channel blockers. Cardioversion for hemodynamically unstable (synchronized)
Ventricular fibrillation: No organized rhythm, no cardiac output = cardiac arrest. Immediate defibrillation (unsynchronized). Begin CPR
Ventricular tachycardia: Wide-complex tachycardia. With pulse + stable: amiodarone. Pulseless or unstable: defibrillate immediately
SVT: Narrow-complex tachycardia. Vagal maneuvers first. If unsuccessful: adenosine 6 mg rapid IV push
3rd-degree heart block: No relationship between P waves and QRS. Atropine temporizing; transcutaneous → transvenous pacing → permanent pacemaker

Synchronized vs Unsynchronized Cardioversion

Synchronized cardioversion: Shock on R wave. Used for SVT, A-fib, A-flutter with a pulse. Patient sedated if time allows
Defibrillation (unsynchronized): Shock delivered immediately. V-fib and pulseless V-tach only. No sedation needed

Post-Cardiac Catheterization Nursing Care

Assess puncture site every 15 min × 4, then every 30 min × 2, then hourly
Femoral access: flat or 15° HOB, keep affected leg straight 4–6 hours
Radial access: apply TR Band compression device; check hand perfusion
Monitor distal pulses and neurovascular status of accessed extremity
Watch for retroperitoneal bleeding (back/flank pain, hypotension, tachycardia — femoral only)
Encourage oral fluids to flush contrast dye; monitor creatinine for contrast nephropathy

NCLEX Tips: Cardiac Nursing

Nitroglycerin: hold if SBP <90, right ventricular MI, or recent PDE-5 inhibitor use (sildenafil)
Hold digoxin if apical pulse <60 bpm — always assess for full minute before giving
S3 = pathological in adults >40 → heart failure until proven otherwise
JVD at 45° = abnormal → right-sided heart failure or cardiac tamponade
V-fib = defibrillate immediately — never use synchronized cardioversion on V-fib
ACE inhibitors cause dry cough in ~10–20% — switch to ARB, not discontinue therapy
Troponin is the gold standard for MI — any elevation indicates myocardial necrosis

Official Resources and Further Reading

External References

AHA Heart Failure — American Heart Association guidelines for heart failure diagnosis and management
AHA Heart Attack — American Heart Association STEMI/NSTEMI information and treatment standards

Frequently Asked Questions: Cardiac Nursing

What is the most important intervention in STEMI?

Time to reperfusion. The goal is primary PCI within 90 minutes of first medical contact. Every minute of delay increases myocardial damage. If PCI is unavailable within 120 minutes, thrombolytics are given.

Why is digoxin dangerous?

Narrow therapeutic index and hypokalemia dramatically increases toxicity risk. Patients on loop diuretics and digoxin simultaneously need close potassium monitoring. Early toxicity: nausea, anorexia, bradycardia, visual changes (yellow-green halos).

When do you withhold nitroglycerin?

When SBP <90 mmHg, right ventricular MI (inferior STEMI — RV depends on preload; nitro causes severe hypotension), HR <50 or >100 with hypotension, or patient used a PDE-5 inhibitor within 24–48 hours.

How do you differentiate left vs right heart failure at the bedside?

Left: crackles on auscultation, low SpO2, orthopnea, PND — fluid backing into lungs. Right: JVD at 45°, bilateral pitting edema, hepatomegaly — fluid backing into the body. Most late-stage HF patients have both.