QUIZ 1 (ACS)

Question 1

A patient arrives at the emergency department with chest pain that has lasted for 20 minutes. The nurse knows that which of the following ECG findings is most indicative of a STEMI?

A. ST-segment depression
B. T-wave inversion
C. ST-segment elevation in two contiguous leads
D. Prolonged PR interval

Answer 1

Answer: C
Rationale: ST-segment elevation in two contiguous leads is the hallmark ECG finding in a STEMI. ST-segment depression and T-wave inversion suggest ischemia or NSTEMI.

Question 2

Which cardiac biomarker is the most specific for myocardial infarction?

A. CK-MB
B. Myoglobin
C. Troponin I
D. LDH

Answer 2

Answer: C
Rationale: Troponin I (or T) is the most specific and sensitive biomarker for myocardial infarction. It rises within 4-6 hours, peaks at 10-24 hours, and remains elevated for up to 14 days.

Question 3

A nurse is assessing a patient with suspected unstable angina. Which of the following findings differentiates unstable angina from a myocardial infarction?

A. Chest pain that is relieved with rest
B. Elevated serum troponin levels
C. ST-segment elevation on ECG
D. Pain that lasts longer than 30 minutes

Answer 3

Answer: B
Rationale: Unstable angina does not cause myocardial necrosis, so troponin levels remain normal. It is characterized by chest pain that occurs unpredictably but is relieved with rest or nitroglycerin.

Question 4

Which statement about NSTEMI is correct?

A. NSTEMI is caused by a total coronary artery occlusion.
B. NSTEMI does not usually cause ST-segment elevation.
C. Thrombolytic therapy is the treatment of choice for NSTEMI.
D. Patients with NSTEMI do not require cardiac catheterization.

Answer 4

Answer: B
Rationale: NSTEMI is caused by a partial occlusion and does not typically show ST-segment elevation. Thrombolytic therapy is only used for STEMI. Patients with NSTEMI undergo cardiac catheterization within 12-72 hours.

Question 5

A patient with a suspected MI reports chest pain that radiates to the left arm and jaw. What other symptom is most common in an acute MI?

A. Epigastric burning
B. Sharp pleuritic pain on inspiration
C. Weakness, nausea, and diaphoresis
D. Pain that improves with deep breathing

Answer 5

Answer: C
Rationale: MI pain is often accompanied by nausea, diaphoresis, and weakness due to activation of the sympathetic nervous system.

Question 6

Which assessment finding would be expected in a patient with a right ventricular infarction?

A. Pulmonary congestion
B. Jugular vein distention
C. Crackles in the lungs
D. Increased urine output

Answer 6

Answer: B
Rationale: Right ventricular infarction can cause JVD, hepatic engorgement, and peripheral edema due to systemic venous congestion.

Question 7

A nurse is assessing an elderly patient with an MI. Which symptom is the patient most likely to report?

A. Severe chest pain
B. Nausea and vomiting
C. Left arm pain
D. Shortness of breath and confusion

Answer 7

Answer: D
Rationale: Older adults often present with atypical symptoms such as confusion, dyspnea, and generalized weakness rather than classic chest pain.

Question 8

What is the priority nursing action for a patient presenting with chest pain?

A. Obtain a 12-lead ECG
B. Administer morphine
C. Obtain a troponin level
D. Give aspirin

Answer 8

Answer: A
Rationale: A 12-lead ECG should be obtained immediately to determine if the patient has ST-segment elevation, guiding treatment decisions.

Question 9

Which medication should be administered first in a patient with suspected MI?

A. Nitroglycerin
B. Morphine
C. Atorvastatin
D. Metoprolol

Answer 9

Answer: A
Rationale: Nitroglycerin is given first to relieve chest pain by vasodilation. Morphine is used if pain persists.

Question 10

Which of the following is a contraindication to thrombolytic therapy?

A. Onset of chest pain 1 hour ago
B. History of GI bleeding 6 months ago
C. STEMI confirmed on ECG
D. Blood pressure of 190/110 mmHg

Answer 10

Answer: D
Rationale: Severe hypertension (≥180/110 mmHg) is a contraindication due to increased risk of intracranial hemorrhage.

Question 11

A patient with an anterior wall MI suddenly develops crackles in the lungs and S3 heart sounds. What complication should the nurse suspect?
A. Cardiogenic shock
B. Left ventricular heart failure
C. Pulmonary embolism
D. Right ventricular infarction

Answer 11

Answer: B
Rationale: Left ventricular failure can occur due to impaired contractility, leading to pulmonary congestion and crackles.

Question 12

Which ECG change is a sign of myocardial infarction resolution after thrombolytic therapy?
A. ST-segment elevation persists
B. Return of ST-segment to baseline
C. Prolonged QT interval
D. New left bundle branch block

Answer 12

Answer: B
Rationale: The return of the ST-segment to baseline indicates successful reperfusion of the myocardium.

Question 13

Which laboratory finding is most concerning in a patient receiving heparin for ACS?
A. Platelet count of 90,000/mm³
B. Hemoglobin of 13 g/dL
C. Troponin of 1.5 ng/mL
D. INR of 1.2

Answer 13

Answer: A
Rationale: A low platelet count suggests heparin-induced thrombocytopenia (HIT), a serious complication.

Question 14

Which statement by a patient recovering from an MI indicates a need for further teaching?
A. “I will take my aspirin every day.”
B. “I can stop taking my beta-blocker when I feel better.”
C. “I should avoid heavy lifting for a while.”
D. “I need to follow a heart-healthy diet.”

Answer 14

Answer: B
Rationale: Beta-blockers should not be stopped abruptly as this increases the risk of rebound hypertension and another MI.

Question 15

Which dietary recommendation is best for a patient with ACS?
A. High-fat, low-carbohydrate diet
B. Low-sodium, low-fat diet
C. High-protein, high-fat diet
D. Low-fiber diet

Answer 15

Answer: B
Rationale: A heart-healthy diet should be low in saturated fat and sodium to reduce cardiovascular risk.

Question 16

A patient presents to the emergency department with chest pain. The provider orders an ECG and cardiac biomarkers. The ECG shows ST-segment depression and T-wave inversion, but the initial troponin level is negative. What should the nurse anticipate?
A. The patient will be discharged home.
B. A second troponin level will be drawn in 3-6 hours.
C. The patient will receive thrombolytic therapy.
D. The patient is experiencing a STEMI.

Answer 16

Answer: B
Rationale: Troponin levels may not rise immediately; serial cardiac biomarkers are needed to determine if an MI has occurred.

Question 17

Which of the following diagnostic tests provides direct visualization of coronary artery blockages?
A. 12-lead ECG
B. Echocardiogram
C. Chest X-ray
D. Coronary angiography

Answer 17

Answer: D
Rationale: Coronary angiography is the gold standard for identifying the location and severity of coronary artery blockages.

Question 18

Which patient is at highest risk for developing ACS?
A. A 45-year-old woman with a history of migraines
B. A 60-year-old man with hypertension and hyperlipidemia
C. A 30-year-old man with a history of anxiety
D. A 55-year-old woman who exercises regularly

Answer 18

Answer: B
Rationale: Hypertension and hyperlipidemia are significant risk factors for atherosclerosis, which can lead to ACS.

Question 19

Which of the following medications is given to prevent platelet aggregation in ACS?
A. Furosemide
B. Metoprolol
C. Clopidogrel
D. Atorvastatin

Answer 19

Answer: C
Rationale: Clopidogrel (Plavix) is an antiplatelet agent that prevents clot formation, reducing the risk of worsening ACS.

Question 20

A nurse is administering nitroglycerin IV to a patient with a STEMI. What is the most important nursing assessment?
A. Monitor blood pressure closely
B. Monitor respiratory rate
C. Assess for nausea and vomiting
D. Evaluate capillary refill

Answer 20

Answer: A
Rationale: IV nitroglycerin can cause hypotension due to vasodilation. Blood pressure should be closely monitored.

Question 21

A patient with a history of ACS asks why they are prescribed aspirin daily. What is the best response?
A. “Aspirin dissolves clots that may form in your coronary arteries.”
B. “Aspirin prevents the platelets from sticking together to form a clot.”
C. “Aspirin lowers your cholesterol levels, reducing plaque buildup.”
D. “Aspirin will help to lower your blood pressure.”

Answer 21

Answer: B
Rationale: Aspirin inhibits platelet aggregation, reducing the risk of clot formation in the coronary arteries.

Question 22

A patient receiving thrombolytic therapy for a STEMI suddenly reports severe headache and confusion. What is the nurse’s priority action?
A. Check the patient’s blood glucose level
B. Stop the thrombolytic infusion immediately
C. Administer naloxone
D. Give additional IV fluids

Answer 22

Answer: B
Rationale: Severe headache and confusion may indicate intracranial hemorrhage, a serious complication of thrombolytic therapy. The infusion should be stopped immediately.

Question 23

Which is the most common complication after an MI?
A. Heart failure
B. Stroke
C. Pulmonary embolism
D. Ventricular dysrhythmias

Answer 23

Answer: D
Rationale: Ventricular dysrhythmias, such as ventricular fibrillation, are the most common cause of death following an MI.

Question 24

A patient with an anterior wall STEMI is at greatest risk for developing which complication?
A. Right-sided heart failure
B. Cardiogenic shock
C. Peripheral edema
D. Pericarditis

Answer 24

Answer: B
Rationale: An anterior wall STEMI affects the left ventricle, impairing cardiac output and leading to cardiogenic shock.

Question 25

A patient recovering from an MI asks when they can resume sexual activity. What is the best response? A. "You should wait at least 6 months before resuming sexual activity." B. "If you can climb two flights of stairs without symptoms, you may resume sexual activity." C. "Sexual activity is not recommended after a heart attack." D. "You can resume sexual activity immediately if you feel ready."

Answer 25

Answer: B Rationale: The "two-flight rule" is often used to assess a patient's cardiac fitness for resuming sexual activity.

Question 25

Which of the following ECG changes is most indicative of myocardial ischemia? A. ST-segment elevation B. Prolonged PR interval C. Q waves D. ST-segment depression

Answer 25

Answer: D Rationale: ST-segment depression indicates ischemia, while ST-segment elevation suggests infarction.

Question 26

Which lifestyle modification should be emphasized for a patient with ACS? A. Eliminating all dietary fat B. Avoiding all physical activity C. Engaging in regular moderate exercise D. Drinking 3-4 alcoholic beverages per day

Answer 26

Answer: C Rationale: Moderate exercise improves cardiovascular health and reduces the risk of future cardiac events.

Question 27

Which statement by a patient recovering from an MI indicates a need for further education? A. "I will take my prescribed medications even if I feel fine." B. "I will attend my cardiac rehab sessions." C. "I will follow a low-fat, low-sodium diet." D. "I should stop taking my beta-blocker once my chest pain is gone."

Answer 27

Answer: D Rationale: Beta-blockers should not be stopped abruptly, as this increases the risk of rebound hypertension and another MI.

Question 28

Which finding indicates that a patient with ACS is experiencing cardiogenic shock? A. Blood pressure of 88/54 mmHg, weak pulse, and cool extremities B. Heart rate of 50 bpm with bounding pulses C. BP of 130/80 mmHg with clear breath sounds D. Complaints of mild chest discomfort

Answer 28

Answer: A Rationale: Cardiogenic shock is characterized by hypotension, weak pulse, and cool extremities due to poor cardiac output.

Question 29

A nurse is teaching a patient about sublingual nitroglycerin. Which statement indicates a need for further teaching? A. "I will keep the tablets in a dark, tightly sealed bottle." B. "If my chest pain is not relieved after one tablet, I can take another after 5 minutes." C. "I should chew the tablet for faster absorption." D. "I should call 911 if chest pain persists after taking 3 tablets."

Answer 29

Answer: C Rationale: Sublingual nitroglycerin should not be chewed—it should dissolve under the tongue for rapid absorption.

Question 30

Which action is the priority for a patient with a STEMI who arrives at a hospital without PCI capability? A. Start thrombolytic therapy within 30 minutes of arrival. B. Administer aspirin and discharge the patient. C. Transport the patient for elective cardiac catheterization. D. Give a beta-blocker immediately.

Answer 30

Answer: A Rationale: If PCI is unavailable, thrombolytic therapy must be started within 30 minutes to dissolve the clot and restore blood flow.

Question 31

Which finding indicates that thrombolytic therapy for STEMI has been successful? A. New onset of chest pain B. Persistent ST-segment elevation C. Return of ST-segment to baseline D. Bradycardia and hypotension

Answer 31

Answer: C Rationale: Return of the ST segment to baseline indicates successful reperfusion of the myocardium.

Question 32

A patient receiving thrombolytic therapy for STEMI is at greatest risk for which complication? A. Stroke B. Infection C. Liver failure D. Electrolyte imbalance

Answer 32

Answer: A Rationale: Stroke (intracranial hemorrhage) is the most serious complication of thrombolytic therapy due to excessive clot breakdown.

Question 33

Which medication is used in ACS to reduce myocardial oxygen demand and heart rate? A. Morphine B. Beta-blockers C. Atorvastatin D. Nitroglycerin

Answer 33

Answer: B Rationale: Beta-blockers (e.g., metoprolol) lower heart rate, blood pressure, and myocardial oxygen consumption.

Question 34

A patient with an MI is at highest risk for developing which dysrhythmia within the first hour? A. Atrial fibrillation B. Sinus bradycardia C. Ventricular fibrillation D. First-degree AV block

Answer 34

Answer: C Rationale: Ventricular fibrillation is the most common cause of sudden cardiac death within the first hour after an MI.

Question 35

Which of the following is an early sign of cardiogenic shock in a patient with an MI? A. Bounding pulses and hypertension B. Increased urine output C. Slow capillary refill and bradycardia D. Cold, clammy skin and hypotension

Answer 35

Answer: D Rationale: Cold, clammy skin and hypotension occur due to decreased cardiac output and impaired tissue perfusion in cardiogenic shock.

Question 36

Which symptom suggests a possible right ventricular infarction? A. Crackles in the lungs B. Jugular vein distention and hypotension C. Pulmonary congestion D. Cyanosis and bradypnea

Answer 36

Answer: B Rationale: Right ventricular infarctions lead to JVD, hypotension, and systemic venous congestion rather than pulmonary congestion.

Question 37

Which statement by a patient recovering from an MI indicates a need for further education? A. "I will avoid smoking to prevent another heart attack." B. "I will take my aspirin daily." C. "I can stop taking my medications once I feel better." D. "I will follow a heart-healthy diet."

Answer 37

Answer: C Rationale: Medications such as beta-blockers, aspirin, and statins must be continued long-term to prevent recurrence.

Question 38

Which dietary recommendation is most appropriate for a patient recovering from ACS? A. High-fat, low-carbohydrate diet B. Low-sodium, low-fat diet C. High-protein, high-fat diet D. Low-fiber diet

Answer 38

Answer: B Rationale: A low-sodium, low-fat diet helps control hypertension and cholesterol, reducing future cardiovascular events.

Question 39

A nurse is teaching a patient with a history of ACS about physical activity. Which statement requires further teaching? A. "I should gradually increase my activity level as tolerated." B. "If I experience chest pain during exercise, I should rest and take nitroglycerin." C. "I should avoid all exercise to prevent another heart attack." D. "Cardiac rehab can help me safely regain strength."

Answer 39

Answer: C Rationale: Regular moderate exercise helps strengthen the heart and reduce the risk of another MI.

Question 40

A patient recovering from an MI asks how long they should wait before driving. What is the best response? A. "You should wait at least 1 week before driving." B. "You can drive as soon as you feel comfortable." C. "You should wait at least 2 weeks or until cleared by your provider." D. "You should never drive again."

Answer 40

Answer: C Rationale: Driving is usually restricted for at least 2 weeks or until the patient is cleared by a healthcare provider.

Question 41

Which statement by a patient taking nitroglycerin sublingual tablets indicates correct understanding? A. "I can take up to three tablets, five minutes apart, if my chest pain does not go away." B. "I should swallow the tablet whole." C. "I can take as many tablets as I need until my pain stops." D. "I should store my nitroglycerin in a warm, humid place."

Answer 41

Answer: A Rationale: Up to 3 doses of nitroglycerin can be taken 5 minutes apart for persistent chest pain before calling 911.

Question 42

Which of the following is an expected side effect of nitroglycerin? A. Hypertension B. Bradycardia C. Headache D. Hypoglycemia

Answer 42

Answer: C Rationale: Headaches are common due to vasodilation. Patients may take acetaminophen if needed.

Question 43

Which of the following lifestyle modifications is most important for a patient recovering from ACS? A. Drinking 3-4 alcoholic beverages per day B. Smoking cessation C. Avoiding all physical activity D. Eating a high-fat diet

Answer 43

Answer: B Rationale: Smoking cessation is the single most effective way to reduce the risk of another MI.

Question 44

Which statement by a patient recovering from ACS indicates a need for further education? A. "I should limit my saturated fat intake." B. "I will take my prescribed statin every night." C. "I can stop my medications once my cholesterol improves." D. "I will monitor my blood pressure regularly."

Answer 44

Answer: C Rationale: Statins and other medications should not be stopped without consulting a healthcare provider.

Question 45

Which medication reduces ventricular remodeling after an MI? A. Beta-blockers B. ACE inhibitors C. Aspirin D. Morphine

Answer 45

Answer: B Rationale: ACE inhibitors (e.g., lisinopril) reduce ventricular remodeling and prevent heart failure.

Question 46

Which is an expected finding 48 hours after an MI? A. Hypothermia B. Fever (100.4°F or 38°C) C. Decreased white blood cell count D. Decreased glucose levels

Answer 46

Answer: B Rationale: A low-grade fever is expected due to the inflammatory response to myocardial necrosis.

Question 47

Which assessment finding would indicate that a patient is experiencing reinfarction after an initial MI? A. ST-segment elevation in previously normal leads B. Resolution of chest pain C. Decrease in cardiac biomarkers D. Hypotension and bradycardia

Answer 47

Answer: A Rationale: New ST-segment elevation in different leads suggests reinfarction, indicating that another area of the heart is affected.

Question 48

A patient with an MI is prescribed a statin medication. What is the primary reason for this prescription? A. To dissolve existing plaque in the coronary arteries B. To reduce cholesterol levels and prevent further plaque buildup C. To reduce myocardial oxygen demand D. To lower blood pressure

Answer 48

Answer: B Rationale: Statins (e.g., atorvastatin) lower LDL cholesterol, reducing the risk of atherosclerotic plaque progression and future cardiac events.

Question 49

Which patient education point is most important for preventing future cardiac events in a patient with ACS? A. "You should take your prescribed medications even if you feel fine." B. "You only need to follow a heart-healthy diet for six months." C. "You can stop taking aspirin once your chest pain resolves." D. "It is safe to resume smoking in moderation."

Answer 49

Answer: A Rationale: Medications such as aspirin, beta-blockers, and statins must be taken long-term to prevent recurrent cardiac events.

Question 50

Scenario: A 58-year-old male arrives at the emergency department (ED) with severe substernal chest pain that started 30 minutes ago while watching TV. The pain radiates to his left arm and jaw. He is diaphoretic, anxious, and rates his pain as 9/10. His blood pressure is 160/95 mmHg, heart rate 102 bpm, respiratory rate 22 breaths/min, and oxygen saturation 96% on room air. An ECG shows ST-segment elevation in leads II, III, and aVF. Question 1: What is the priority action the nurse should take? A. Obtain a troponin level B. Administer IV morphine C. Prepare for emergent PCI D. Obtain a chest X-ray

Answer 50

Answer: C Rationale: This patient is experiencing an inferior-wall STEMI, as indicated by ST-segment elevation in leads II, III, and aVF. The priority action is to restore coronary blood flow via percutaneous coronary intervention (PCI) within 90 minutes. While troponin testing, pain management, and a chest X-ray are part of the ACS workup, rapid reperfusion therapy takes precedence.

Question 51

Scenario: A 67-year-old female with hypertension and hyperlipidemia presents to the ED with chest pain that started while she was walking. The pain is relieved with rest and nitroglycerin. Her ECG shows ST-segment depression and T-wave inversion, and her initial troponin is negative. Question 2: Which diagnosis is most likely? A. STEMI B. NSTEMI C. Unstable angina D. Pericarditis

Answer 51

Answer: C Rationale: Unstable angina (UA) presents with new-onset or worsening chest pain but negative cardiac biomarkers (troponin). ST depression and/or T-wave inversion suggest ischemia. In contrast, NSTEMI has positive troponins, and STEMI presents with ST-segment elevation. Pericarditis often presents with diffuse ST elevation and pericardial friction rub.

Question 52

A 72-year-old male with NSTEMI is started on IV heparin, aspirin, and clopidogrel. The patient asks why he needs two antiplatelet medications. Question 3: What is the best response by the nurse? A. "Aspirin reduces blood clotting, and clopidogrel prevents platelet aggregation." B. "These medications dissolve the clot and restore blood flow." C. "You need them to control your blood pressure and cholesterol." D. "You only need aspirin, but clopidogrel is given as extra protection."

Answer 52

Answer: A Rationale: Dual antiplatelet therapy (DAPT) with aspirin and clopidogrel (or ticagrelor) is standard in NSTEMI and STEMI to prevent platelet aggregation and reduce clot formation. Heparin prevents new clot formation but does not dissolve existing clots.

Question 53

Scenario: A 60-year-old male is admitted with a STEMI and undergoes PCI with stent placement. Two hours later, he reports severe chest pain similar to his initial symptoms. Question 4: What is the most concerning possible cause of this symptom? A. Reperfusion injury B. Stent thrombosis C. Gastric reflux D. Anxiety attack

Answer 53

Answer: B Rationale: Recurrent chest pain after PCI raises concern for stent thrombosis, a life-threatening complication that can cause reinfarction. Immediate ECG and cardiac biomarkers are needed to confirm reinfarction and determine further intervention.

Question 54

Scenario: A 55-year-old male presents to a rural hospital with STEMI in leads V1-V4 (suggesting anterior wall infarction). The hospital does not have PCI capability. Question 5: What is the most appropriate next step? A. Start thrombolytic therapy within 30 minutes B. Transfer to a PCI-capable hospital, delaying treatment C. Administer IV heparin and monitor D. Give IV fluids and recheck troponins in 3 hours

Answer 54

Answer: A Rationale: If PCI is unavailable within 120 minutes, thrombolytic (fibrinolytic) therapy must be initiated within 30 minutes to dissolve the clot and restore blood flow. Delaying treatment worsens myocardial damage.

Question 55

Scenario: A patient post-STEMI suddenly develops hypotension (BP 80/50 mmHg), cool and clammy skin, and weak pulses. Question 6: Which complication is most likely? A. Pulmonary embolism B. Cardiogenic shock C. Heart failure D. Anxiety attack

Answer 55

Answer: B Rationale: Cardiogenic shock occurs when a damaged left ventricle fails to pump blood effectively, causing hypotension, poor perfusion, and cool skin. It is a life-threatening emergency requiring vasopressors, fluids, and possible mechanical support.

Question 55

Scenario: A 68-year-old patient with inferior-wall STEMI (leads II, III, aVF) develops jugular vein distention (JVD), hypotension, and clear lungs. Question 7: Which treatment should be avoided? A. IV fluids B. Cardiac monitoring C. Pain management D. Nitrates

Answer 55

Answer: D Rationale: Right ventricular infarction causes preload-dependent hypotension. Nitrates can dangerously drop blood pressure by reducing preload, worsening hypotension. IV fluids help maintain cardiac output.

Question 56

Scenario: A 74-year-old male with type 2 diabetes presents with fatigue and shortness of breath but no chest pain. Question 8: Which test is most important to rule out MI? A. Chest X-ray B. Troponin levels C. D-dimer test D. CT angiography

Answer 56

Answer: B Rationale: Diabetic patients often have "silent" MIs due to cardiac neuropathy. Troponin levels help confirm myocardial injury.

Question 57

Scenario: A patient recovering from an MI asks how to prevent future heart attacks. Question 9: Which lifestyle change is most critical? A. Drinking red wine daily B. Increasing salt intake C. Smoking cessation D. Avoiding all exercise

Answer 57

Answer: C Rationale: Smoking cessation is the single most important modifiable risk factor to prevent recurrent MI.

Question 58

Scenario: A patient with ACS is prescribed a statin, beta-blocker, aspirin, and nitroglycerin. Question 10: Which statement indicates a need for further teaching? A. "I can stop taking my statin once my cholesterol is normal. B. ""I should take my nitroglycerin if I have chest pain." C. "I should avoid fatty and salty foods." D. "I will take my aspirin every day."

Answer 58

Answer: A Rationale: Statins should not be discontinued once cholesterol levels normalize because they prevent atherosclerosis progression and reduce MI risk.

Question 59

What does the T wave represent in a ECG?

Answer 59

The T wave on an ECG (electrocardiogram) represents ventricular repolarization, which is the relaxing phase of the ventricles after they contract.

Question 60

What does the ST interval mean on an ECG?

Answer 60

The ST segment on an ECG (electrocardiogram) represents the period between ventricular depolarization and repolarization. It is the flat, isoelectric line between the end of the QRS complex (ventricular depolarization) and the beginning of the T wave (ventricular repolarization).