Acute Coronary Syndrome Practice Questions

30 multiple-choice questions on Acute coronary syndrome for paramedic and EMT students, from Chapter 18 (Cardiovascular Emergencies). Read each question, pick your answer, then tap Show answer to check it and read the explanation.

30 practice questions

1. A septic patient with a BP of 74/40 and a heart rate of 146 develops ST depression and a rising troponin, but has no history of coronary disease. Which term best describes this injury?

   1. A. Type 2 MI from a supply and demand mismatch
   2. B. Type 1 MI from a newly ruptured coronary plaque
   3. C. Acute pericarditis from the infection
   4. D. Stable angina brought on by the fever
   Show answer

   Answer: A. Type 2 MI from a supply and demand mismatch

   Under the Fourth Universal Definition, a type 2 MI is ischemic injury caused by an imbalance between oxygen supply and demand (here hypotension and tachycardia) rather than an acute plaque rupture, which defines a type 1 MI. Treatment focuses on the cause, not on rushing to the cath lab. Pericarditis does not cause a troponin rise with ischemic ST depression in this setting, and stable angina does not raise troponin.

2. What distinguishes an NSTEMI from unstable angina?

   1. A. ST elevation on the 12-lead
   2. B. Pain lasting more than 5 minutes
   3. C. Elevated cardiac biomarkers
   4. D. Pain that is relieved by rest
   Show answer

   Answer: C. Elevated cardiac biomarkers

   Both may show ST depression or T wave inversion without ST elevation, but in NSTEMI troponin is elevated, indicating myocardial necrosis. This cannot be determined in the field.

3. A 64-year-old's angina used to come on only after climbing two flights of stairs. Over the past week it comes with walking across a room and lasts longer. How should you classify this?

   1. A. Stable angina that needs a medication refill
   2. B. Unstable angina, an acute coronary syndrome
   3. C. Normal angina that varies from day to day
   4. D. Noncardiac pain because it comes and goes
   Show answer

   Answer: B. Unstable angina, an acute coronary syndrome

   Angina that is new, occurring at rest, or increasing in frequency, duration or ease of onset (crescendo angina) is unstable angina, an ACS that can progress to MI. Stable angina keeps a predictable pattern. A worsening pattern is not normal variation, and pain that comes and goes is typical of ischemia, not a sign that it is noncardiac.

4. A 38-year-old woman who gave birth 3 weeks ago has crushing chest pain and an anterior STEMI. She has no risk factors for heart disease. Which cause should you consider?

   1. A. Atherosclerotic plaque in an older artery
   2. B. Stress-related gastric ulcer perforation
   3. C. Pulmonary hypertension of pregnancy
   4. D. Spontaneous coronary artery dissection
   Show answer

   Answer: D. Spontaneous coronary artery dissection

   Spontaneous coronary artery dissection is a tear in the coronary wall that mainly affects women under 50, especially around pregnancy, and causes many pregnancy-related MIs. She still gets standard STEMI care and transport to a PCI center. Atherosclerosis is uncommon at her age without risk factors, a perforated ulcer does not cause ST elevation, and pulmonary hypertension does not explain an anterior STEMI.

5. A point-of-care troponin is normal in a patient whose ischemic-sounding chest pain began 45 minutes ago. How should this result be used?

   1. A. It does not rule out MI because it is too early
   2. B. It rules out MI and allows him to refuse transport
   3. C. It shows that the pain comes from the stomach
   4. D. It means the 12-lead can be skipped
   Show answer

   Answer: A. It does not rule out MI because it is too early

   Troponin takes time to rise after myocardial injury, so a single normal value soon after onset cannot exclude MI; serial testing is needed, and the 12-lead remains the key test for STEMI. A normal early troponin does not rule out MI, make a refusal of transport safe, or show that the pain comes from the stomach, and it does not replace the ECG.

6. A 59-year-old says he had crushing chest pain for 3 hours before calling because he hoped it was indigestion. In most STEMI systems, which part of the delay to reperfusion is usually the longest?

   1. A. The time before the patient seeks help
   2. B. The time EMS spends on scene
   3. C. The time from PCI center arrival to balloon
   4. D. The time needed to acquire a 12-lead
   Show answer

   Answer: A. The time before the patient seeks help

   Studies of STEMI timelines consistently find that the interval from symptom onset to calling for help is the largest and hardest delay to shorten, which is why public education urges people to call 911 promptly for possible heart attack symptoms. Scene time, door-to-device time at the PCI center and the time to obtain a 12-lead are important but are usually much shorter.

7. A man's wife wants to drive him to the hospital for chest pain instead of waiting for EMS. What is the best reason to advise calling 911?

   1. A. The hospital will see him sooner if he arrives by private car
   2. B. Driving lowers his heart's need for oxygen
   3. C. EMS gives him medications that dissolve the clot
   4. D. EMS can treat VF and send a 12-lead for direct cath lab
   Show answer

   Answer: D. EMS can treat VF and send a 12-lead for direct cath lab

   Arriving by EMS allows early defibrillation if VF occurs, early aspirin and a prehospital 12-lead that can activate the cath lab and direct him to a PCI center. Arriving by private car usually delays care rather than speeding it. Stress and the car ride do not lower oxygen demand, and EMS in most systems does not give clot-dissolving drugs.

8. Three family members have headaches and nausea after running a generator in the garage. The grandfather, who has coronary disease, has chest pressure and new ST depression. What best explains his chest pressure?

   1. A. Carbon monoxide has cut oxygen delivery to his heart
   2. B. Anxiety over the other family members' symptoms
   3. C. A viral infection that has spread through the family
   4. D. Pericarditis brought on by the generator fumes
   Show answer

   Answer: A. Carbon monoxide has cut oxygen delivery to his heart

   Carbon monoxide binds hemoglobin and impairs oxygen release, so people with coronary disease can develop ischemia, MI and dysrhythmias from exposure; give high-flow oxygen, remove everyone from the source, and remember that SpO2 can read falsely normal. Anxiety and a viral illness do not explain a shared headache from a running generator, and the fumes do not cause pericarditis.

9. A patient's chest pain came and went for 2 days and became constant 3 hours ago. A 12-lead shows STEMI. Which time matters most for reperfusion decisions?

   1. A. The first brief episode of pain 2 days ago
   2. B. The time the 12-lead was obtained
   3. C. The start of the constant pain 3 hours ago
   4. D. The time his family called 911
   Show answer

   Answer: C. The start of the constant pain 3 hours ago

   Reperfusion timelines, such as the 12-hour window for fibrinolysis, are counted from the onset of continuous ischemic symptoms (here, the start of the constant pain), so record that time carefully. The first brief episode marks unstable angina rather than the occlusion, and the times of the ECG or the 911 call are system intervals, not symptom onset.

10. During an interfacility transfer after a femoral-artery cardiac catheterization, the patient has a firm, growing swelling in the groin at the puncture site. What should you do first?

    1. A. Apply firm direct pressure just above the site
    2. B. Apply a tourniquet high on the thigh
    3. C. Place a cold pack and recheck it in 30 minutes
    4. D. Have him bend the hip to ease the pain
    Show answer

    Answer: A. Apply firm direct pressure just above the site

    An expanding hematoma means the arterial puncture is bleeding; firm manual pressure just above the skin puncture, over the arterial entry point, controls it while you notify the receiving team. A tourniquet would cut off flow to the whole leg, a cold pack does not stop arterial bleeding, and bending the hip can worsen bleeding from the femoral site.

11. Ten days after a large anterior MI, a patient suddenly develops right-sided weakness and slurred speech. Which complication most likely explains this?

    1. A. The infarct has now extended into the right ventricle
    2. B. Fluid has built up around the heart
    3. C. A clot from the injured left ventricle has embolized
    4. D. His aspirin has caused a stomach bleed
    Show answer

    Answer: C. A clot from the injured left ventricle has embolized

    A large anterior MI can leave a weak, akinetic area of the left ventricle where a clot forms; pieces can break off and cause an embolic stroke, so treat this as an acute stroke and transport to a stroke center. An RV infarct does not cause focal neurologic signs, pericardial fluid does not cause a stroke, and a GI bleed would cause weakness without these focal findings.

12. Why is the benefit of reperfusion greatest when a STEMI is treated within the first 2 to 3 hours after symptom onset?

    1. A. The clot can no longer be opened after 3 hours have passed
    2. B. Heart muscle dies quickly at first, so more is saved early
    3. C. Troponin is not yet present to block the drugs
    4. D. The coronary artery is wider in the first hours
    Show answer

    Answer: B. Heart muscle dies quickly at first, so more is saved early

    Myocardial necrosis spreads from the inner layer outward over hours, so the amount of muscle that can be saved falls steeply with time, which is why every minute of delay matters. Reperfusion can still help up to 12 hours or longer in some cases. Troponin does not block treatment, and the artery does not change in size.

13. The HEART score used by emergency physicians to estimate risk in chest pain includes which elements?

    1. A. Heart rate, ECG, airway, respirations, temperature
    2. B. Hypotension, exertion, arm pain, radiation, time
    3. C. History, ECG, age, risk factors and troponin
    4. D. History, exam, aspirin use, rhythm, transport time
    Show answer

    Answer: C. History, ECG, age, risk factors and troponin

    HEART stands for History, ECG, Age, Risk factors and Troponin; each is scored 0 to 2, and low scores identify patients at low short-term risk of a major cardiac event. It is a hospital decision aid and does not replace a full prehospital ACS workup. The other lists (vital signs, pain features such as arm pain or radiation, or transport details) are made-up expansions that do not match the tool.

14. You are transferring a patient in cardiogenic shock after an MI who has a microaxial heart pump (such as an Impella) inserted through the right femoral artery. What is an important nursing concern during transport?

    1. A. Bend the hip to 90 degrees so the device stays in place
    2. B. Turn the device off during loading to avoid damage
    3. C. Expect a strong radial pulse from the steady device flow
    4. D. Keep the leg straight; check pulses and device position
    Show answer

    Answer: D. Keep the leg straight; check pulses and device position

    Femoral microaxial pumps can migrate or kink if the hip is flexed, and they can cause bleeding or limb ischemia, so keep the leg straight, secure the catheter, and check distal pulses, the insertion site and the console's position alarms; travel with a trained team member. Bending the hip risks displacement, the device should not be turned off, and its continuous flow may leave a weak or absent pulse rather than a strong one.

15. A STEMI patient received a fibrinolytic at a small hospital, and his pain has eased. What is the usual next step?

    1. A. Transfer if pain or ST elevation returns
    2. B. Admit locally with no plans for angiography
    3. C. Start heparin and observe locally
    4. D. Transfer to a PCI center for angiography
    Show answer

    Answer: D. Transfer to a PCI center for angiography

    Current ACC/AHA ACS guidance supports transfer to a PCI-capable center after fibrinolysis, with urgent PCI if reperfusion fails or the patient becomes unstable, and routine angiography within the following hours otherwise. Transferring only if the pain or ST elevation returns, or keeping him on heparin locally without angiography, misses the residual narrowing that routine early angiography is meant to treat.

16. A 58-year-old man with chest pressure has chewed aspirin, and a 12-lead shows no STEMI. His BP is 148/88. What is the most appropriate next medication?

    1. A. Nitroglycerin 0.4 mg SL
    2. B. Fentanyl 1 mcg/kg IV
    3. C. Furosemide 40 mg IV
    4. D. Adenosine 6 mg IV
    Show answer

    Answer: A. Nitroglycerin 0.4 mg SL

    With ongoing ischemic pain, adequate blood pressure, and no contraindications, sublingual nitroglycerin is the next step. Opioids are reserved for pain refractory to nitrates.

17. During transfer after a femoral cardiac catheterization, a patient develops back and flank pain, a falling BP and a rising heart rate, with no visible groin swelling. What should you suspect?

    1. A. Kidney stone triggered by the contrast dye
    2. B. Muscle strain from lying flat after the procedure
    3. C. Retroperitoneal bleeding from the access site
    4. D. Allergic reaction to the contrast dye
    Show answer

    Answer: C. Retroperitoneal bleeding from the access site

    A femoral puncture made above the inguinal ligament can bleed into the retroperitoneum, where large amounts of blood hide without a visible hematoma; back or flank pain with signs of shock are the clues. Treat for hemorrhagic shock and notify the receiving team. A kidney stone, muscle strain and contrast allergy do not explain progressive shock after the procedure.

18. Patients with diabetes are more likely to have a 'silent' MI without chest pain primarily because of:

    1. A. Higher pain tolerance
    2. B. Autonomic neuropathy
    3. C. Smaller coronary arteries
    4. D. Effects of insulin therapy
    Show answer

    Answer: B. Autonomic neuropathy

    Diabetic autonomic neuropathy can blunt the transmission of cardiac pain, so MIs may present only with dyspnea, weakness, or altered mental status.

19. A patient being transferred after a cardiac catheterization through the wrist has a compression band on the radial artery. What should you monitor?

    1. A. The hand's color, warmth and sensation, and bleeding
    2. B. The tightness of the band rather than the hand itself
    3. C. The pulse in the opposite arm for comparison
    4. D. Pupils, since the procedure can cause a stroke
    Show answer

    Answer: A. The hand's color, warmth and sensation, and bleeding

    A radial compression band controls bleeding from the puncture, but if too tight or left too long it can cut off flow to the hand, so check the hand's color, warmth, capillary refill and sensation, and watch for bleeding or swelling; follow the sending facility's instructions on the band. Watching the band alone misses ischemia, the opposite arm tells you nothing about this hand, and pupils are not the focus here.

20. Occlusion of which coronary artery is most often missed on a standard 12-lead because it may cause little or no ST elevation?

    1. A. Left anterior descending
    2. B. Right coronary artery
    3. C. Left main coronary artery
    4. D. Left circumflex artery
    Show answer

    Answer: D. Left circumflex artery

    The circumflex supplies the lateral and posterior walls, which the standard 12 leads view poorly, so its occlusion may show only subtle changes or ST depression in V1 to V3; posterior leads V7 to V9 and serial tracings help. LAD occlusion usually shows clear anterior ST elevation, right coronary (RCA) occlusion clear inferior elevation, and left main occlusion tends to cause widespread ST depression with elevation in aVR.

21. A patient with chronic kidney disease and no chest pain has a mildly raised troponin that does not change over several hours. How is this best described?

    1. A. Acute MI, because a raised troponin defines an MI
    2. B. A lab error, since troponin is specific to MI
    3. C. Unstable angina caused by kidney failure
    4. D. Chronic myocardial injury rather than an acute MI
    Show answer

    Answer: D. Chronic myocardial injury rather than an acute MI

    The universal definition separates myocardial injury (a troponin above the normal limit) from MI, which requires a rising or falling pattern plus clinical evidence of ischemia. A stable, mildly raised level in kidney disease reflects chronic injury. A raised troponin alone does not define an MI, a lab error is unlikely because troponin rises in many conditions (sepsis, PE, heart failure, kidney disease), and unstable angina has no troponin rise.

22. A patient with known stable angina asks when he should call 911 if chest pain starts at home. What is the standard AHA advice?

    1. A. After three nitro doses 5 minutes apart
    2. B. If the pain lasts more than 30 minutes after it starts
    3. C. He should drive himself to the hospital instead
    4. D. If the pain is not better 5 minutes after one nitro
    Show answer

    Answer: D. If the pain is not better 5 minutes after one nitro

    AHA guidance tells patients to call 911 if chest discomfort is not improved or is getting worse 5 minutes after one sublingual nitroglycerin, rather than waiting to take more doses. Waiting to take three doses or for 30 minutes of pain delays reperfusion, and driving himself risks collapse at the wheel and skips EMS care.

23. A patient with chest pain has no ST elevation, but his 12-leads show new ST depression in several leads that comes and goes with the pain. How should this finding be viewed?

    1. A. As a sign of low-risk stable angina
    2. B. As artifact from patient movement
    3. C. As a sign of high-risk NSTE-ACS
    4. D. As an indication for fibrinolytics
    Show answer

    Answer: C. As a sign of high-risk NSTE-ACS

    Dynamic ST depression that appears with pain marks active ischemia and places the patient in a higher-risk NSTE-ACS group that needs early invasive evaluation; report it and repeat 12-leads with any change. It is not low-risk stable angina or movement artifact, and fibrinolytics are not indicated for ST depression without ST elevation (except a posterior MI pattern).

24. A STEMI patient had a hemorrhagic stroke 3 years ago. A PCI center is 40 minutes away. How does the stroke history affect his reperfusion options?

    1. A. It rules out both fibrinolysis and PCI for this STEMI
    2. B. It rules out fibrinolysis, but PCI is still an option
    3. C. It does not change his reperfusion options
    4. D. It makes fibrinolysis safer than PCI for him
    Show answer

    Answer: B. It rules out fibrinolysis, but PCI is still an option

    A prior intracranial hemorrhage is an absolute contraindication to fibrinolytics, but it does not prevent PCI, which is the preferred strategy anyway when it can be done in time, so transport to the PCI center. It does not rule out PCI, it clearly affects the choice of reperfusion, and it makes fibrinolysis more dangerous, not safer.

25. You plan to repeat 12-leads every 10 to 15 minutes on a chest pain patient. What helps make the serial tracings comparable?

    1. A. Move the chest leads slightly each time for a new view
    2. B. Switch the filter to monitor mode
    3. C. Record each one in a new patient position
    4. D. Leave the electrodes in place or mark their positions
    Show answer

    Answer: D. Leave the electrodes in place or mark their positions

    Small shifts in electrode position can change the size of the QRS and ST segments and mimic or hide dynamic changes, so leave the electrodes on or mark their positions between tracings. Moving the leads or changing the patient's position between tracings makes them harder to compare, and monitor-mode filtering distorts the ST segments.

26. Large anterior MIs carry a particularly high risk of which complication?

    1. A. Isolated right heart failure
    2. B. Sinus bradycardia from vagal tone
    3. C. Second-degree AV block type I
    4. D. Left ventricular pump failure
    Show answer

    Answer: D. Left ventricular pump failure

    The LAD supplies a large portion of the left ventricle, so anterior MIs often cause significant pump failure and cardiogenic shock. Vagal bradycardia and Wenckebach are more typical of inferior MIs.

27. A 24-year-old had a flu-like illness last week and now has chest pain, a heart rate of 128, ST elevation in several leads and a raised troponin. A cath lab finds normal coronary arteries. What is the most likely diagnosis?

    1. A. Acute myocarditis
    2. B. Coronary vasospasm from the flu shot
    3. C. Spontaneous pneumothorax
    4. D. Stable angina
    Show answer

    Answer: A. Acute myocarditis

    Viral myocarditis inflames the heart muscle and can cause chest pain, tachycardia, ST elevation, troponin rise and even heart failure or dysrhythmias, mimicking STEMI in a young person with normal coronaries. Vasospasm from a vaccine is not the expected cause, a pneumothorax does not raise troponin with ST elevation, and stable angina does not raise troponin.

28. Two hours after successful fibrinolysis for STEMI, a patient's chest pain returns and the ST elevation reappears during transfer. What does this suggest?

    1. A. The artery has reoccluded and needs urgent PCI
    2. B. Normal pain expected after fibrinolysis
    3. C. Pericarditis caused by the fibrinolytic
    4. D. A delayed allergic reaction to the fibrinolytic drug
    Show answer

    Answer: A. The artery has reoccluded and needs urgent PCI

    Recurrent ischemic pain with returning ST elevation after fibrinolysis means the artery has closed again (reocclusion), which calls for urgent angiography and rescue PCI; notify the receiving center and continue STEMI care. This is not expected pain, pericarditis does not appear this way within hours, and an allergic reaction does not cause recurrent ST elevation.

29. An 86-year-old who lives independently has an anterior STEMI with stable vital signs. Her daughter asks whether she is too old for the cath lab. What is the best response?

    1. A. PCI is reserved for patients under age 75
    2. B. Medical therapy is preferred at her age
    3. C. Age alone does not exclude her from PCI
    4. D. The nearest hospital is best for older adults
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    Answer: C. Age alone does not exclude her from PCI

    Older adults have the highest absolute benefit from reperfusion, and age alone does not exclude anyone from PCI or make medical therapy the preferred choice or bypass a PCI center; decisions consider frailty, goals of care and patient wishes. There is no age cutoff of 75 for PCI, and routing her to a non-PCI hospital solely because of age delays reperfusion.

30. A patient with years of worsening exertional angina has a total occlusion of his right coronary artery, yet only a small area of muscle is damaged. What best explains this?

    1. A. His heart muscle had switched to burning fat for energy
    2. B. The artery reopened on its own early
    3. C. Heart cells regrew after the damage
    4. D. Collateral vessels had grown around the narrowing
    Show answer

    Answer: D. Collateral vessels had grown around the narrowing

    A narrowing that develops slowly stimulates small collateral arteries from neighboring vessels, which can keep some of the territory alive when the artery finally closes, so infarct size varies between patients. Switching fuels does not protect ischemic muscle, the artery is still totally occluded so it did not reopen, and heart muscle cells do not regrow after infarction.