NCLEX-RN® Cardiac Disorders: MI, Heart Failure, Shock, and Hypertension
Master the cardiac conditions most tested on the NCLEX-RN®: myocardial infarction, heart failure, cardiogenic shock, and hypertension — priority assessment findings, interventions, and medication safety.
The big picture
Cardiac questions make up a significant slice of NCLEX-RN® Physiological Integrity. The exam doesn't ask you to memorize every EKG waveform — it asks you to recognize the most dangerous finding, choose the safest next action, and know what to report immediately. This guide walks through the four cardiovascular conditions tested most heavily: myocardial infarction, heart failure, shock, and hypertension.
Myocardial infarction (MI)
What NCLEX® wants you to know
An MI occurs when a coronary artery is blocked long enough that myocardial cells die. The two major types are:
| Type | Defining feature | EKG finding |
|---|---|---|
| STEMI (ST-elevation MI) | An acute MI pattern that requires rapid reperfusion assessment; often reflects an occluded coronary artery | Diagnostic ST-elevation pattern on the ECG; Q waves are not required |
| NSTEMI (Non-ST-elevation MI) | MI without the diagnostic ST-elevation pattern; coronary anatomy varies | May show ST depression, T-wave inversion, or a nondiagnostic ECG; a rise and/or fall in troponin with ischemic evidence helps establish MI |
Classic vs. atypical presentation
Most NCLEX® stems describe classic crushing chest pain, but atypical presentations are heavily tested — especially in women, older adults, and diabetic clients:
- Classic: substernal pressure, diaphoresis, radiation to left jaw/arm, nausea
- Atypical (test frequently): fatigue, epigastric pain, jaw pain alone, shortness of breath, or no chest pain at all
Priority lab values
| Lab | Normal range | MI significance |
|---|---|---|
| Cardiac troponin I or T | Assay-specific 99th-percentile upper reference limit | Preferred biomarker for myocardial injury. Interpret serial rise/fall with symptoms, ECG, timing, and the laboratory's high-sensitivity assay; one universal cutoff or timeline is unsafe. |
| CK-MB | < 3–5% of total CK | Rises 4–8 h; returns to normal in ~72 h |
| BNP | < 100 pg/mL | Elevated in heart failure that may accompany MI |
Move beyond the MONA mnemonic
MONA is not a treatment sequence. Activate the chest-pain or acute-coronary-syndrome pathway, obtain a 12-lead ECG promptly, establish monitoring and vascular access, and assess contraindications. Give chewable aspirin when ordered and not contraindicated. Oxygen is used for hypoxemia or respiratory distress rather than routinely for every patient. Nitroglycerin requires blood-pressure and medication checks, including recent phosphodiesterase-5 inhibitor use. Opioids are not a routine first-line intervention and can complicate assessment.
Nursing priorities: the first four actions
- Obtain and interpret a 12-lead EKG promptly — often within 10 minutes of first medical contact or emergency-department arrival for suspected acute coronary syndrome, not within 10 minutes of symptom onset. One ECG may be nondiagnostic; repeat assessment and serial biomarkers may be needed.
- Establish IV access (two large-bore peripheral IVs)
- Continuous cardiac monitoring — dysrhythmias are the leading cause of MI death in the first hour
- Activate the acute-coronary-syndrome/STEMI pathway and notify the team — reperfusion is time-critical when indicated. PCI targets depend on whether the patient presents directly to a PCI-capable center or needs transfer; “90 minutes from first medical contact” is not a universal deadline.
The AHA/ACC 2025 acute coronary syndromes guideline emphasizes a coordinated invasive and reperfusion strategy. The AHA STEMI receiving-center measures distinguish direct arrivals from transferred patients.
Go deeper: For a systematic method to interpret ECG findings, recognize common rhythms, and connect changes to nursing priorities, see the ECG/EKG interpretation guide.
Post-MI teaching points NCLEX® loves
- Report any new chest pain, palpitations, or dizziness immediately
- Activity gradually increases — cardiac rehabilitation is standard
- Beta-blockers slow heart rate and reduce myocardial O₂ demand; do not stop abruptly
- ACE inhibitors (enalapril, lisinopril) reduce cardiac remodeling — monitor for dry cough and hyperkalemia
Heart failure (HF)
Heart failure is the inability of the heart to pump enough blood to meet the body's needs. NCLEX® distinguishes left-sided vs. right-sided failure because the signs differ.
Left vs. right heart failure: what you must know
| Left-sided HF | Right-sided HF | |
|---|---|---|
| Cause | MI, hypertension, aortic valve disease | Left HF (most common), pulmonary hypertension, right MI |
| Key sign | Pulmonary edema (fluid backs into lungs) | Peripheral edema, hepatomegaly, JVD |
| Lung sounds | Crackles/rales | Clear |
| Classic symptom | Dyspnea, orthopnea, PND | Dependent pitting edema, ascites |
| Lab marker | BNP > 100 pg/mL | Same |
NCLEX® tip: If the stem mentions jugular vein distension (JVD) + peripheral edema + clear lungs, think right-sided HF. If it mentions crackles + orthopnea, think left-sided HF.
NCLEX® priority assessment findings
Call the provider or escalate immediately for:
- SpO₂ dropping below 92%
- Respiratory rate > 30
- Frothy, pink-tinged sputum (acute pulmonary edema — life-threatening)
- Sudden weight gain > 2–3 lb in 24 hours or > 5 lb in a week
HF medication classes you must know
| Drug class | Example | Key nursing concern |
|---|---|---|
| Loop diuretics | Furosemide (Lasix) | Monitor K⁺ (hypokalemia risk); daily weights |
| ACE inhibitors | Lisinopril | Dry cough, hyperkalemia, first-dose hypotension |
| ARBs | Losartan | No dry cough; still causes hyperkalemia |
| Beta-blockers | Carvedilol, metoprolol | Hold if HR < 60; do not stop abruptly |
| Digoxin | Digoxin | Narrow therapeutic range (0.5–2 ng/mL); toxicity signs: nausea, visual changes, bradycardia |
Teaching the patient with HF
- Weigh daily at the same time, same scale, same clothing — weight is the earliest sign of fluid retention
- Restrict sodium to 2 g/day unless otherwise ordered
- Restrict fluid intake if ordered (typically 1.5–2 L/day for severe HF)
- Elevate legs to reduce peripheral edema; sleep with head of bed elevated to reduce orthopnea
Cardiogenic shock
Cardiogenic shock occurs when the heart fails to pump enough blood to maintain perfusion — most often after a massive MI. It is a medical emergency.
Classic triad on NCLEX®
- Hypotension (SBP < 90 mmHg)
- Signs of poor perfusion: cool, clammy, mottled skin; decreased urine output (< 30 mL/hr); altered mental status
- Evidence of cardiac cause: elevated PCWP (wedge pressure), S3 gallop
Differentiating shock types — a high-yield table
| Shock type | Skin | BP | HR | Cause |
|---|---|---|---|---|
| Cardiogenic | Cool, clammy | Low | High | MI, HF |
| Hypovolemic | Cool, pale | Low | High | Hemorrhage, dehydration |
| Distributive (septic) | Warm early, cool late | Low | High | Infection |
| Neurogenic | Warm, dry | Low | Low or normal | Spinal cord injury |
| Anaphylactic | Flushed, urticarial | Low | High | Allergen |
Nursing actions in cardiogenic shock
- Position the client flat (unless pulmonary edema is present — then semi-Fowler's)
- Administer oxygen; prepare for possible intubation
- Monitor continuous EKG, arterial line if available
- Administer vasoactive medications according to the shock protocol. A monitored proximal peripheral IV may be used temporarily when delay in central access would postpone treatment; inspect the site frequently and follow extravasation procedures.
- Monitor urine output hourly — goal ≥ 30 mL/hr indicates adequate renal perfusion
- Prepare for possible intra-aortic balloon pump (IABP)
Hypertension
Definitions the exam uses
| Stage | SBP | DBP |
|---|---|---|
| Normal | < 120 | < 80 |
| Elevated | 120–129 | < 80 |
| Stage 1 HTN | 130–139 | 80–89 |
| Stage 2 HTN | ≥ 140 | ≥ 90 |
| Hypertensive crisis | > 180 | > 120 |
Based on AHA/ACC 2017 guidelines, which NCLEX® continues to reference.
Hypertensive urgency vs. emergency
| Urgency | Emergency | |
|---|---|---|
| BP | Severely elevated | Severely elevated |
| End-organ damage | None | Yes |
| Examples of damage | — | MI, stroke, papilledema, AKI, aortic dissection |
| Treatment | Oral medications, outpatient | IV medications, ICU, immediate intervention |
NCLEX® key: The difference is end-organ damage, not the BP number. A BP of 220/120 without symptoms is urgency. A BP of 180/110 with chest pain and change in vision is an emergency.
Antihypertensive drug classes — nursing priorities
| Class | Drug | Key teaching |
|---|---|---|
| ACE inhibitors | Lisinopril, enalapril | Dry cough (switch to ARB); K⁺ monitoring; teratogenic — stop if pregnant |
| ARBs | Losartan, valsartan | Same K⁺ risk; no cough; also teratogenic |
| Calcium channel blockers | Amlodipine, diltiazem | Peripheral edema; do not eat grapefruit |
| Thiazide diuretics | Hydrochlorothiazide | Monitor K⁺, glucose, uric acid |
| Beta-blockers | Metoprolol | May mask adrenergic hypoglycemia symptoms; abrupt withdrawal can be harmful, so taper only under prescriber direction |
Lifestyle teaching the exam tests
- Reduce sodium to < 2.3 g/day (ideally < 1.5 g)
- Follow DASH diet (Dietary Approaches to Stop Hypertension): fruits, vegetables, low-fat dairy, whole grains
- Exercise: at least 30 minutes of moderate aerobic activity most days
- Limit alcohol: ≤ 2 drinks/day for men, ≤ 1 drink/day for women
- Stress reduction; adequate sleep
- Do not change or stop antihypertensives without prescriber guidance; some agents, especially clonidine and beta-blockers, require a planned taper to avoid withdrawal or rebound effects
Clinical judgment focus: What NCLEX® actually asks
The NCLEX-RN® primarily tests what the nurse does first. For cardiac questions, use this priority order:
- Airway and breathing first — if the patient has pulmonary edema, position is the first nursing action (high Fowler's), then oxygen
- Circulation second — assess perfusion (BP, HR, skin color/temperature, UO, LOC)
- Notify provider for any new or worsening cardiac finding — do not wait to see if it resolves
- Document and monitor — after the emergency actions
Common NCLEX® traps in cardiac questions:
- Giving nitroglycerin when SBP < 90 — incorrect; hold it and notify the provider
- Ignoring "3 lb weight gain in 2 days" in a HF patient — incorrect; this needs to be reported
- Assuming jaw pain alone is not cardiac — incorrect; atypical MI presentation
- Continuing digoxin when HR < 60 — incorrect; hold and notify
FAQ
What is the most specific lab for myocardial infarction?
Cardiac troponin I or T is the preferred biomarker for myocardial injury. High-sensitivity assays can detect change earlier than older assays, and reference limits differ by method. A myocardial infarction diagnosis requires the clinical picture plus a rise and/or fall in troponin with evidence of ischemia; an elevated value alone does not identify the cause.
How does NCLEX® distinguish left from right heart failure?
Left-sided HF causes pulmonary symptoms: dyspnea, orthopnea, paroxysmal nocturnal dyspnea, and crackles. Right-sided HF causes systemic venous congestion: JVD, dependent edema, hepatomegaly, and ascites. Most questions describe one or the other presentation clearly.
When should the nurse hold nitroglycerin?
Hold nitroglycerin when systolic BP is below 90 mmHg, when the patient has taken a PDE-5 inhibitor (sildenafil/Viagra) within 24–48 hours, or when the patient has right ventricular MI (nitrates cause severe hypotension in RV MI by reducing preload).
What makes cardiogenic shock different from hypovolemic shock on an NCLEX® question?
Both present with hypotension, tachycardia, and cool/clammy skin. The key difference is the cause — cardiogenic shock will have signs of cardiac failure (S3 gallop, crackles, low EF on echo, elevated BNP) while hypovolemic shock will have a history of fluid/blood loss. On the NCLEX®, the stem usually makes the cause clear.
What is hypertensive emergency and how is it treated?
Hypertensive emergency is severe hypertension (SBP > 180 / DBP > 120) with end-organ damage (chest pain, neuro changes, vision changes, renal failure). Treatment is IV antihypertensives (nicardipine, labetalol, sodium nitroprusside) in an ICU setting. The goal is to reduce BP by no more than 25% in the first hour to avoid cerebral hypoperfusion.
Key takeaways
- MI: Use the acute-coronary-syndrome pathway rather than a MONA sequence. Obtain an ECG promptly, interpret serial assay-specific troponins, screen medication contraindications, and prepare for reperfusion when indicated.
- Heart failure: Left-sided = pulmonary; right-sided = peripheral. Furosemide + ACE inhibitor + beta-blocker are the core drug classes. Daily weights are the most important patient teaching point.
- Cardiogenic shock: BP low, CO low, PCWP high. Vasopressors via central line. Monitor urine output hourly.
- Hypertension: Know the stages. Hypertensive emergency = severely elevated BP + end-organ damage. Teach DASH diet, low sodium, regular exercise.
Sources: NCSBN, 2026 NCLEX-RN® Test Plan; American Heart Association, 2025 CPR and Emergency Cardiovascular Care Guidelines; ACC/AHA, Guidelines and Clinical Documents. Exact drug selection, reperfusion targets, and vasoactive access depend on the active protocol and patient condition.
See also:
- NGN Case Study: Adult with STEMI
- NGN Case Study: Atrial Fibrillation and Stroke Risk
- Electrolytes Made Simple
- NCLEX-RN® Pharmacology Guide
- NCLEX-RN® Oxygenation and Ventilation
Practice on RN Clarity: Question Bank · NGN Case Studies · Drug Cards