Cardiac Nursing

Cardiac Nursing

Cardiac conditions are among the most commonly tested topics on the NCLEX. A strong understanding of heart failure, myocardial infarction, dysrhythmias, cardiac medications, and hemodynamic monitoring is essential for exam success and clinical practice. For a quick reference guide, see the Cardiac Nursing Cheat Sheet.

Heart Failure

Heart failure (HF) occurs when the heart cannot pump enough blood to meet the body's metabolic demands. It is classified by the side of the heart affected and the type of dysfunction.

Left-Sided Heart Failure: The left ventricle fails to adequately pump blood forward into systemic circulation. Blood backs up into the pulmonary vasculature, causing pulmonary congestion. Key symptoms include dyspnea, orthopnea, paroxysmal nocturnal dyspnea (PND), crackles (rales) on lung auscultation, frothy pink-tinged sputum, tachycardia, fatigue, and decreased urine output. Think "left = lungs."

Right-Sided Heart Failure: The right ventricle fails to pump blood into the pulmonary artery. Blood backs up into systemic venous circulation. Key symptoms include jugular vein distention (JVD), peripheral edema (dependent), hepatomegaly (enlarged liver), ascites, weight gain, and nausea. Right-sided failure most commonly results from left-sided failure. Think "right = rest of the body."

Systolic vs. Diastolic Dysfunction:

• Systolic (HFrEF): Reduced ejection fraction (less than 40%). The ventricle cannot contract forcefully enough. Treated with ACE inhibitors, beta-blockers, diuretics, and aldosterone antagonists.
• Diastolic (HFpEF): Preserved ejection fraction (50% or greater). The ventricle is stiff and cannot relax properly to fill. Treated with diuretics, blood pressure control, and rate control.

Nursing Interventions for Heart Failure: Monitor daily weights (same time, same scale, same clothing). Restrict sodium intake (less than 2 g/day). Restrict fluids as ordered (typically 1.5-2 L/day). Elevate the head of bed to facilitate breathing. Monitor intake and output. Administer medications as prescribed. Educate about recognizing worsening symptoms (weight gain of more than 2 lbs in one day or 5 lbs in one week).

Myocardial Infarction (MI)

An MI occurs when blood flow to a portion of the myocardium is blocked, causing tissue ischemia and necrosis. It is classified as:

• STEMI (ST-Elevation MI): Complete coronary artery occlusion with ST elevation on ECG. Requires emergent reperfusion therapy (PCI or fibrinolytics within 90-120 minutes of symptom onset).
• NSTEMI (Non-ST-Elevation MI): Partial occlusion with ST depression or T-wave inversion on ECG. Elevated cardiac biomarkers (troponin). Managed with anticoagulation, antiplatelet therapy, and possible cardiac catheterization.

Classic MI Symptoms: Crushing substernal chest pain radiating to the left arm, jaw, neck, or back. Diaphoresis, nausea, shortness of breath, and a sense of impending doom. Women, elderly, and diabetic patients may present atypically with fatigue, indigestion, or jaw pain without classic chest pain.

Treatment -- MONA (no longer the standard order but helpful for recall):

• M -- Morphine: For pain unrelieved by nitroglycerin. Use cautiously; evidence is mixed.
• O -- Oxygen: Administer if SpO2 is less than 94%. Routine supplemental oxygen is no longer recommended for normoxic patients.
• N -- Nitroglycerin: Sublingual every 5 minutes for up to 3 doses. Contraindicated with PDE5 inhibitor use and with right ventricular MI (preload-dependent).
• A -- Aspirin: 160-325 mg chewed immediately (antiplatelet effect). First intervention for suspected MI.

Cardiac biomarkers: Troponin I and T are the most specific and sensitive markers. Troponin rises within 3-6 hours, peaks at 12-24 hours, and remains elevated for 7-14 days. CK-MB rises within 3-6 hours and returns to normal within 48-72 hours.

Dysrhythmias

Understanding cardiac rhythms is critical for NCLEX success. Key rhythms to recognize include:

• Sinus Bradycardia: Regular rhythm, rate less than 60 bpm. May be normal in athletes. Treat symptomatic bradycardia with atropine, then pacing if needed.
• Sinus Tachycardia: Regular rhythm, rate greater than 100 bpm. Usually a response to an underlying condition (fever, pain, hypovolemia). Treat the cause, not the rhythm.
• Atrial Fibrillation (A-Fib): Irregularly irregular rhythm with no discernible P waves. Major risk is thromboembolism (stroke). Treatment includes rate or rhythm control (beta-blockers, calcium channel blockers, amiodarone) and anticoagulation (warfarin, DOACs).
• Atrial Flutter: Sawtooth-pattern flutter waves. Regular or irregular depending on conduction ratio. Treatment similar to A-Fib.
• Ventricular Tachycardia (V-Tach): Wide QRS complexes, rate greater than 150 bpm. If the patient has a pulse, treat with amiodarone or synchronized cardioversion. If pulseless, initiate CPR and defibrillation (treat as V-Fib).
• Ventricular Fibrillation (V-Fib): Chaotic, no organized rhythm. Patient is pulseless. Immediate CPR and defibrillation. Administer epinephrine and amiodarone per ACLS protocol.
• Heart Blocks: First-degree (prolonged PR interval, benign), Second-degree Type I/Wenckebach (progressively lengthening PR until dropped QRS, usually benign), Second-degree Type II (constant PR with randomly dropped QRS, may need pacing), Third-degree/Complete (P waves and QRS independent, requires pacemaker).

Cardiac Medications

• Beta-Blockers (-olol): Reduce heart rate, blood pressure, and myocardial oxygen demand. Monitor for bradycardia, hypotension, and fatigue. Do not stop abruptly.
• ACE Inhibitors (-pril): Reduce afterload and prevent cardiac remodeling. Monitor for hypotension, hyperkalemia, and cough.
• Antiarrhythmics: Amiodarone is the most commonly used. Monitor for pulmonary toxicity, thyroid dysfunction, liver toxicity, and corneal deposits. Lidocaine is used for ventricular arrhythmias; adenosine for SVT (rapid IV push followed by flush).
• Anticoagulants: Heparin and warfarin for atrial fibrillation and mechanical valves. Monitor aPTT for heparin and INR for warfarin.

Hemodynamic Monitoring

Invasive hemodynamic monitoring provides real-time assessment of cardiovascular function:

• Central Venous Pressure (CVP): Normal 2-6 mmHg. Reflects right atrial pressure and preload. Elevated in fluid overload, right heart failure, and cardiac tamponade. Decreased in hypovolemia.
• Pulmonary Artery Pressure (PAP): Normal systolic 20-30 mmHg, diastolic 8-15 mmHg. Pulmonary artery wedge pressure (PAWP) reflects left atrial pressure. Elevated PAWP indicates left heart failure.
• Cardiac Output (CO): Normal 4-8 L/min. Cardiac index (CI) adjusts for body surface area (normal 2.5-4.0 L/min/m2). Decreased in heart failure, cardiogenic shock.

Cardiac Catheterization and Post-Procedure Care

Cardiac catheterization is used for diagnostic evaluation and interventional procedures (PCI, stent placement). Post-procedure nursing care includes: monitor the access site (usually femoral or radial artery) for bleeding, hematoma, and loss of distal pulses. Maintain bed rest with the affected extremity straight for 4-6 hours (femoral approach). Assess neurovascular status of the affected limb (color, temperature, sensation, movement, capillary refill, pulses). Encourage fluid intake to promote contrast dye excretion. Monitor for contrast-induced nephropathy (rising creatinine, decreased urine output). Report chest pain, dysrhythmias, or signs of retroperitoneal bleeding immediately.

NCLEX Cardiac Question Tips

Prioritize airway, breathing, and circulation. For chest pain questions, aspirin is typically the first action. Know the difference between emergent rhythms (V-Fib and pulseless V-Tach require defibrillation) and stable rhythms. Remember that patient assessment comes before intervention in most situations. Review more cardiac concepts at the Physiological Study Guide and test your knowledge with Physiological Flashcards.