Hypertension (HTN)
The "silent killer" — one of the most commonly tested cardiac topics.
Hypertension is defined as a consistent blood pressure of ≥130/80 mmHg (per ACC/AHA guidelines). It is called the "silent killer" because it is often asymptomatic until organ damage occurs. Primary (essential) hypertension accounts for approximately 90–95% of cases and has no identifiable cause. Secondary hypertension has an identifiable cause (renal disease, Cushing's, pheochromocytoma, medications).
HTN Classification
- Normal
- Systolic <120 · Diastolic <80
- Elevated
- Systolic 120–129 · Diastolic <80
- Stage 1 HTN
- Systolic 130–139 · Diastolic 80–89
- Stage 2 HTN
- Systolic ≥140 · Diastolic ≥90
- Hypertensive Crisis
- Systolic >180 · Diastolic >120
Complications of Uncontrolled HTN
- Stroke (CVA)
- Heart failure
- Myocardial infarction
- Kidney damage (nephrosclerosis)
- Retinopathy (vision loss)
- Aortic aneurysm/dissection
Nursing Interventions & Teaching
- DASH diet (Dietary Approaches to Stop Hypertension): rich in fruits, vegetables, whole grains, low-fat dairy; low in sodium (<2,300 mg/day, ideally <1,500 mg)
- Regular exercise (30 min most days)
- Weight management, limit alcohol, smoking cessation
- Medication compliance — teach patients NOT to stop antihypertensives abruptly (rebound hypertension)
- Monitor for orthostatic hypotension with antihypertensives (rise slowly)
This is an emergency. Symptoms may include severe headache, visual changes, chest pain, shortness of breath, nosebleeds, and altered mental status. Administer IV antihypertensives (nitroprusside, labetalol). Goal: reduce BP gradually — no more than 25% in the first hour. Dropping too fast can cause stroke or MI.
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Coronary Artery Disease (CAD) & Myocardial Infarction (MI)
Know the progression from stable angina → unstable angina → MI.
CAD Overview
CAD occurs when atherosclerotic plaque builds up in the coronary arteries, reducing blood flow to the myocardium. Risk factors include hypertension, hyperlipidemia, diabetes, smoking, obesity, sedentary lifestyle, family history, and age (males >45, females >55).
Angina Comparison
- Stable Anginachronic
- Occurs with exertion or stress. Duration <5 minutes. Predictable. Relieved by rest and/or nitroglycerin.
- Unstable Anginaemergency
- At rest or minimal exertion. Duration longer, may last >15 minutes. Unpredictable — NEW or CHANGING pattern. NOT fully relieved by rest or nitro. Pre-infarction emergency.
Myocardial Infarction (Heart Attack)
An MI occurs when coronary blood flow is completely blocked, causing myocardial tissue death. Time is critical: "Time is muscle."
- Classic symptoms: Crushing substernal chest pain radiating to left arm, jaw, back, or neck; diaphoresis (sweating); nausea/vomiting; shortness of breath; anxiety/feeling of impending doom
- Atypical presentation (women, elderly, diabetics): May present with fatigue, indigestion, back pain, jaw pain, or shortness of breath WITHOUT classic chest pain
M — Morphine (relieves pain, decreases preload)
O — Oxygen (if SpO₂ <94%)
N — Nitroglycerin (vasodilator — up to 3 doses, 5 min apart; hold if SBP <90)
A — Aspirin (chew 325 mg immediately — antiplatelet)
Also: 12-lead EKG within 10 minutes, troponin levels, prepare for cardiac catheterization/PCI.
Nitroglycerin Teaching (Heavily Tested!)
- Take 1 tablet sublingual at onset of chest pain; sit or lie down
- If no relief (or pain worsens) 5 minutes after the first dose → call 911 immediately (possible MI)
- While waiting for help, may take a 2nd tablet, then a 3rd 5 minutes later (3 tablets total)
- Side effects: headache (most common), hypotension, dizziness
- Store in dark, glass container; replace every 6 months
- Should tingle/burn under the tongue if potent
- Do NOT take with erectile dysfunction medications (sildenafil/Viagra) — severe hypotension risk
Heart Failure (HF)
Left-sided vs right-sided — this comparison is tested on nearly every exit exam.
Heart failure occurs when the heart cannot pump effectively enough to meet the body's metabolic demands. It can be left-sided, right-sided, or both (biventricular). Left-sided failure is the most common and usually leads to right-sided failure over time.
- Left-Sided HFbacks into lungs
- Blood backs up into the LUNGS. Key symptoms: dyspnea, orthopnea, crackles (rales), cough (may be pink frothy sputum), fatigue, tachycardia. Caused by CAD, MI, hypertension, aortic stenosis.
- Right-Sided HFbacks into body
- Blood backs up into the BODY (systemic). Key symptoms: peripheral edema, JVD, hepatomegaly, ascites, weight gain. #1 cause is left-sided HF; also COPD, pulmonary hypertension.
Left-sided failure → fluid backs up into pulmonary vasculature → LUNG symptoms. Right-sided failure → fluid backs up into systemic circulation → peripheral edema, JVD, liver congestion.
Key Nursing Interventions for HF
- Daily weights — most important assessment! Weight gain of 2 lbs/day or 5 lbs/week = report to provider (fluid retention)
- Monitor strict I&O
- Low sodium diet (≤2,000 mg/day)
- Fluid restriction (typically 1.5–2 L/day)
- Elevate HOB (semi-Fowler's or high-Fowler's) to ease breathing
- Administer medications: ACE inhibitors, beta-blockers, diuretics, digoxin
- Assess lung sounds for crackles every shift
- Monitor BNP levels (elevated in HF — >100 pg/mL suggests HF)
? Left-sided heart failure causes crackles in the lungs. Why?
EKG Basics for LPNs
You won't need to interpret complex rhythms, but you MUST know these basics.
As an LPN/LVN, you are expected to recognize life-threatening rhythms, monitor telemetry, and notify the RN or provider of changes. You are not expected to interpret all 12-lead EKGs in depth — but you must know the basics.
Normal Sinus Rhythm (NSR)
- Rate: 60–100 bpm
- Rhythm: Regular
- P wave before every QRS
- PR interval: 0.12–0.20 seconds
- QRS: <0.12 seconds
Rhythms LPNs Must Recognize
- Sinus Bradycardia<60 bpm
- Regular rhythm, just slow. Assess symptoms; atropine if symptomatic.
- Sinus Tachycardia>100 bpm
- Regular rhythm, fast. Treat the underlying cause (pain, fever, anxiety, dehydration).
- Atrial Fibrillationirregular
- No identifiable P waves, "irregularly irregular." Anticoagulants (risk of stroke/clot); rate control.
- V-Tach150–250 bpm
- Wide, bizarre QRS; no P waves. If pulse present → amiodarone. If pulseless → defibrillation + CPR.
- V-Fibchaotic
- No organized rhythm, wavy line. IMMEDIATE defibrillation + CPR. This is pulseless.
- Asystoleflat line
- No electrical activity. CPR + epinephrine. Do NOT defibrillate asystole.
V-Fib, pulseless V-Tach, and asystole are all pulseless rhythms requiring immediate BLS/ACLS. Remember: defibrillation is for V-Fib and pulseless V-Tach ONLY — never for asystole (there's no rhythm to "shock back").
Valvular Heart Disease
Focus on mitral and aortic — those are most commonly tested.
Stenosis vs Regurgitation
- Stenosis: Valve doesn't open fully → blood flow is restricted through the valve
- Regurgitation (insufficiency): Valve doesn't close fully → blood flows backward
- Mitral Stenosis
- Often caused by rheumatic fever. Dyspnea, fatigue, A-fib common. Rumbling murmur.
- Mitral Regurgitation
- Blood flows back into left atrium. Fatigue, dyspnea, palpitations. Blowing murmur.
- Aortic Stenosis
- Classic triad: syncope, angina, dyspnea on exertion. Systolic murmur. Common in elderly.
- Aortic Regurgitation
- Blood flows back into left ventricle. Bounding pulses, widened pulse pressure.
Patients with valvular disease may need antibiotic prophylaxis before dental procedures to prevent infective endocarditis. Teach patients to inform dentists about their heart condition.
Peripheral Vascular Disease (PVD) & DVT
Arterial vs venous — this comparison is a favorite on nursing exams.
- Arterial Insufficiencylegs DOWN
- Intermittent claudication (pain walking, relieved by rest). Pale, shiny, cool, hairless skin. Diminished/absent pulses. Painful toe-tip ulcers with well-defined borders. Minimal edema.
- Venous Insufficiencylegs UP
- Aching, heaviness relieved by elevation. Brown stasis dermatitis, warm skin. Pulses present. Medial malleolus ulcers with irregular borders. Significant edema.
Arterial = "Art" is pale/cool (like marble) — legs DOWN. Venous = "Venus" is warm/swollen — legs UP.
Deep Vein Thrombosis (DVT)
A blood clot forms in a deep vein, usually in the leg. Major risk: clot can dislodge and travel to the lungs → pulmonary embolism (PE).
- Signs: Unilateral leg swelling, warmth, redness, tenderness, positive Homans' sign (calf pain with dorsiflexion — not always reliable)
- Diagnosis: Doppler ultrasound, D-dimer
- Treatment: Anticoagulants (heparin → warfarin), bed rest with affected leg elevated, do NOT massage the leg
- Prevention: Early ambulation post-surgery, SCDs (sequential compression devices), TED hose, adequate hydration
Sudden onset dyspnea, chest pain, tachycardia, tachypnea, anxiety, feeling of impending doom. This is a life-threatening emergency — notify provider immediately, administer O₂, prepare for CT angiography.
Key Cardiac Medications
Medications you'll see on every cardiac question.
- Nitroglycerinvasodilator
- SL for angina; up to 3 doses q5min. Hold if SBP <90. Headache = expected. No PDE-5 inhibitors (Viagra).
- Aspirinantiplatelet
- Chew 325 mg during MI. Daily low-dose for CAD prevention. Monitor for bleeding.
- Metoprolol (-olol)beta-blocker
- Decreases HR, BP, and cardiac workload. Hold if HR <60 or SBP <90. Do NOT stop abruptly.
- Lisinopril (-pril)ACE inhibitor
- First-line for HF and HTN. Side effects: dry cough, hyperkalemia, angioedema.
- Losartan (-sartan)ARB
- Alternative when ACE causes cough. Same benefits, no cough. Monitor K⁺.
- Digoxincardiac glycoside
- Increases contractility, decreases HR. Check apical pulse 1 full minute — hold if <60. Therapeutic level: 0.5–2.0 ng/mL. Toxicity: nausea, visual changes (halos), bradycardia.
- Furosemide (Lasix)loop diuretic
- Reduces fluid overload in HF. Causes hypokalemia. Monitor K⁺, daily weights.
- Heparinanticoagulant
- IV — monitor aPTT. Antidote: protamine sulfate. Watch for HIT (heparin-induced thrombocytopenia).
- Warfarin (Coumadin)anticoagulant
- Oral — monitor INR (therapeutic: 2.0–3.0). Antidote: Vitamin K. Avoid leafy greens in excess. Many drug interactions.
- Amiodaroneantiarrhythmic
- Used for V-Tach, A-Fib. Monitor for thyroid dysfunction, pulmonary toxicity, liver toxicity. Wear sunscreen (photosensitivity).
- Statins (-statin)antilipidemic
- Lower LDL cholesterol. Take at bedtime. Monitor liver function. Report muscle pain (rhabdomyolysis risk).
1) Check apical pulse for 1 full minute before giving — hold if <60. 2) Monitor potassium — hypokalemia increases digoxin toxicity risk. 3) Know toxicity signs: nausea, bradycardia, yellow-green visual halos.
Key Labs
Ranges vary by lab, facility, and textbook — for exams, use the range given in the question. See the full NCLEX-PN lab-value reference & sources →
- Troponin<0.04 ng/mL
- MOST specific marker for MI. Rises 4–6 hrs after injury. Stays elevated 10–14 days.
- BNP<100 pg/mL
- Elevated in heart failure. Higher = worse failure.
- INR0.8–1.1 normal; 2.0–3.0 on warfarin
- Monitors warfarin therapy. >3.0 = bleeding risk.
- aPTT25–35 seconds
- Monitors heparin therapy. Therapeutic: 1.5–2.5x normal.
- Total Cholesterol<200 mg/dL
- LDL (<100 = optimal), HDL (>40 male, >50 female).
- Potassium3.5–5.0 mEq/L
- Critical for cardiac rhythm. Both hypo and hyper can cause arrhythmias.
- Magnesium1.7–2.2 mg/dL
- Low Mg = arrhythmias. Often depleted with loop diuretics.
Frequently Asked Questions
Common student questions on this topic.
What is the difference between angina and a heart attack (MI)?
What does an elevated troponin level mean?
What are the signs and symptoms of left vs right-sided heart failure?
What is the difference between atrial fibrillation and ventricular fibrillation?
How do I teach a patient to use nitroglycerin?
Why do we restrict sodium and fluid in heart failure?
Quick-Reference Cheatsheet
Every key point from this guide on a single printable page.
Cardiac System Cheatsheet
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Drilling the meds side of cardiac? The Cardiovascular Medications cheatsheet puts ACE inhibitors, beta-blockers, nitrates, and anticoagulants on one page.