ECG Test – Acute Coronary Syndromes

The cases presented here are designed to test and enhance your clinical decision-making skills in dealing with suspected acute myocardial infarction. Each case has been carefully selected to represent a scenario that you may encounter in any clinical setting - from primary care to emergency rooms - where patients with potential acute MI might present. This quiz aims to ensure that every clinician, irrespective of their background, is equipped with the fundamental knowledge and skills necessary to identify these life-threatening cases. As you progress through each case, remember that these scenarios are typical of what you might encounter in real-life clinical practice. They serve as a vital reminder of the importance of swift and accurate diagnosis, immediate intervention, and the application of evidence-based guidelines in the management of acute MI. This quiz should be considered a prerequisite for any healthcare professional working in environments where managing patients with suspected acute MI is a possibility.

19 question(s) with answers and explanations.

Question 1

A 57-year-old male, a long-term smoker with a history of controlled hypertension, wakes up in the middle of the night with severe, crushing chest pain radiating to his left arm and jaw. He reports a recent increase in episodes of chest discomfort during exertion. His father had a heart attack at 60. The patient is pale, diaphoretic, and in distress. The patient's ECG is presented below. What is the diagnosis?

• ○ NSTEMI (Non ST elevation myocardial infarction)
• ✓ STEMI (ST elevation myocardial infarction), presumably late phase
• ○ Myocarditis
• ○ Early repolarization
• ○ Male pattern (benign ST elevations)

Explanation. Anterior STEMI with loss of R-waves in anterior precordial leads, leading to the development of QS-complexes, indicating the late phase of STEMI.

Question 2

A 64-year-old female, diabetic, and obese patient presents with a sudden onset of shortness of breath and chest pressure while walking. She mentions occasional episodes of chest pain over the past month, which she attributed to acid reflux. Her brother had a coronary artery bypass grafting at age 69. She appears anxious and dyspneic. The ECG is presented below. What is the diagnosis?

• ○ Pulmonary embolism with myocardial ischemia
• ✓ STEMI (ST elevation myocardial infarction)
• ○ NSTEMI (Non ST elevation myocardial infarction)
• ○ Early repolarization
• ○ Left bundle branch block

Explanation. This is STEMI due to occlusion of LCX (left circumflex artery), which was dominant (i.e. supplied the inferior wall), leading to inferoposterior and lateral acute MI.

Question 3

A 53-year-old male, with no known history of heart disease, experiences intense, constricting chest pain that started while he was shoveling snow. The patient has a 20-year history of smoking and a sedentary lifestyle. He experienced palpitations and a brief syncope just prior to arrival to the emergency room (ER). The patient's ECG is presented below. What is the diagnosis?

• ○ Pulmonary embolism with myocardial ischemia
• ○ Left bundle branch block
• ○ Early repolarization
• ○ NSTEMI (Non ST elevation myocardial infarction)
• ✓ STEMI (ST elevation myocardial infarction)

Explanation. Large anterior STEMI due to proximal occlusion of LAD.

Question 4

A 68-year-old female, with a history of gastritis, hypertension and hypercholesterolemia, reports sudden, sharp chest pain radiating to her back, accompanied by nausea. The patient is breathless and appears somewhat anxious. The patient's ECG is presented below. Which is the next appropriate step? STEMI Example 5

• ○ Admission to regular ward with ECG monitoring, including ST segment monitoring and troponin assays
• ○ Admission to CCU (coronary care unit) due to risk of developing an acute coronary syndrome
• ○ Discharge due to benign ECG pattern (early repolarization) and a history of gastritis.
• ✓ Immediate administration of platelet inhibitors, anticoagulants and urgent coronary angiografi, with the aim of performing PCI.

Explanation. This is inferior STEMI (note reciprocal ST depressions in aVL) and immediate angiography is required.

Question 5

A 60-year-old male with a recent diagnosis of type 2 diabetes and a 20-year history of smoking experiences sudden, severe chest discomfort and a feeling of pressure on his chest. Today, while resting at home, the discomfort escalated rapidly into unbearable pain, prompting an emergency call. Upon arrival, the paramedics note that the patient is pale, diaphoretic, and experiencing severe respiratory distress. They immediately perform a 12-lead ECG. As they prepare for transport, the patient suddenly loses consciousness and goes into cardiac arrest with a shockable rhythm. A prompt defibrillation successfully restores sinus rhythm. The patient is rapidly transported to the hospital. The patient is conscious, and stable but continues to experience chest pain upon arrival. The patient's ECG is presented below. What is the next appropriate step?

• ○ Admission to the ICU for stabilization
• ✓ Emergent coronary angiography with the aim of performing PCI
• ○ Admission to the CCU due to high risk of recurrent cardiac arrest
• ○ Thrombolysis in the emergency room (ER)

Explanation. The 12-lead ECG shows STEMI and the patient is resuscitated after cardiac arrest. This is a class I indication for immediate coronary angiography.

Question 6

A 55-year-old female, with a history of smoking and obesity, experiences sudden onset of severe chest pain while resting. She reports experiencing mild chest discomfort and breathlessness during exertion in the past few weeks. She has a family history of heart disease. The patient's ECG is presented below. What is the diagnosis?

• ○ STEMI, early phase
• ✓ STEMI, late phase
• ○ NSTEMI, late phase
• ○ NSTEMI, early phase

Question 7

A 49-year-old male, with a high-stress job and a history of occasional chest discomfort, experiences intense substernal chest pain that started during a heated argument. He has a history of hypertension. The patient's ECG is presented below. What is the diagnosis?

• ○ Early repolarization pattern with J-waves
• ○ Early repolarization pattern without J-waves
• ○ NSTEMI (Non ST Elevation Myocardial Infarction)
• ○ Myocarditis due to generalized ST elevations
• ✓ STEMI (ST Elevation Myocardial Infarction)

Explanation. Inferolateral STEMI.

Question 8

A 67-year-old male presents with acute chest pain and a feeling of tightness that began while he was climbing stairs. He has been experiencing short episodes of dyspnea over the past month, especially during physical exertion. The patient's ECG is presented below. What is the diagnosis?

• ○ Right bundle branch block, further interpretation of ischemia not possible.
• ○ Left bundle branch block, further interpretation of ischemia not possible.
• ✓ Right bundle branch block with signs of ongoing myocardial ischemia
• ○ Right bundle branch block with signs of ongoing myocardial ischemia, potentially STEMI

Explanation. Ischemic ST deviations are mostly visible on right bundle branch block, as evident here in leads V1-V3 (ST depressions). In leads II, aVF and III there are signs of ST segment elevation. If this patient experiences chest pain, an emergent angiography is warranted. Repeated ECGs may be helpful.

Question 9

A 58-year-old female, with a history of left ventricular hypertrophy and heart failure, suddenly experiences chest pain and tightness while walking her dog. She has never experienced such symptoms before. The patient appears anxious and slightly breathless. The patient's ECG is presented below. What is the diagnosis?

• ○ No signs of ischemia (ST-T changes secondary to hypertrophy)
• ○ Possibly NSTEMI
• ✓ Possibly NSTEMI
• ○ Certain STEMI due to hyperacute T waves

Explanation. She has a history of hypertrophy and the ECG changes may be due to hypertrophy. However, there are ST elevations in all precordial leads (V1-V6), which is not common in hypertrophy (which typically displays ST depressions in V5-V6). The large T waves may be due to hypertrophy but could be due to hyperacute ischemia. There are no reciprocal ST depressions, as typical for ischemia. Conclusion: the patient's symptoms must determine whether acute coronary angiography is warranted. Waiting for troponine results is inappropriate if the patient experiences ongoing chest pain.

Question 10

A 62-year-old male, with a history of smoking and controlled hypertension, reports abrupt onset of severe chest pain radiating to his neck, starting while watching television. The patient's ECG is presented below. What is the diagnosis?

• ○ NSTEMI
• ○ Left ventricular hypertrophy (ST-T changes secondary to hypertrophy)
• ○ Left bundle branch block (ST-T changes secondary to hypertrophy)
• ✓ STEMI

Explanation. Inferoposterior (inferobasal) STEMI.

Question 11

A 64-year-old female, with a recent history of unexplained fatigue and mild chest discomfort, experiences sudden, severe chest pain radiating to her right shoulder, accompanied by shortness of breath. The patient's ECG is presented below. What is the diagnosis?

• ○ Aortic dissection
• ✓ STEMI
• ○ NSTEMI
• ○ Pulmonary embolism

Question 12

A 42-year-old female presents with sudden onset of fatigue and lightheadedness while shopping. She reports a vague discomfort in her upper abdomen. Her blood pressure is 100/60 mmHg. On examination, she appears anxious and reports feeling unusually short of breath. The patient's ECG is presented below. What is the diagnosis?

• ○ Pulmonary embolism
• ○ Brugada syndrome (coved ST elevations)
• ○ Presumably heart failure, due to previous anterior myocardial infarction (Q-waves present)
• ✓ STEMI

Explanation. This is anterior STEMI with manifested Q waves (loss of R waves) in V1-V4.

Question 13

A 50-year-old male, with a known history of depression, calls emergency services reporting intense emotional stress followed by a sudden, sharp pain in his chest. He has no prior history of heart disease and leads an active lifestyle. On arrival, the paramedics find him sweating and in moderate distress. The patient's ECG is presented below. What is the next appropriate step?

• ✓ Urgent coronary angiography
• ○ Troponin levels determine if angiography is urgently needed
• ○ Hyperkalemia
• ○ ST-T changes typical of digoxin

Explanation. The symptoms along with ST elevations – regardless of their morphology, presence, or absence of reciprocal ST depressions – should prompt an emergent angiography. Troponins must not delay the decision to perform angiography.

Question 14

A 37-year-old female, with no significant medical history, experiences a sudden onset of palpitations and a feeling of impending doom. She reports a mild, non-specific chest discomfort and a recent increase in stress at work. Her vitals are stable, but her blood pressure is 240/120 mmHg. The patient's ECG is presented below. What is the diagnosis?

• ✓ STEMI
• ○ Hypokalemia
• ○ Hypocalcemia
• ○ Hypercalcemia
• ○ NSTEMI

Explanation. Inferoposterior STEMI. This patient had a spontaneous dissection in the RCA (right coronary artery).

Question 15

A 67-year-old male with a history of COPD presents with increasing shortness of breath and a productive cough. During examination, he suddenly complains of chest pain radiating to his throat. He appears pale and diaphoretic. The ECG is performed immediately, as presented below. What are the key considerations in this case?

• ○ Exacerbated COPD
• ○ Pulmonary embolism
• ○ Anterior STEMI
• ✓ Inferior STEMI

Question 16

A 55-year-old female, with a history of rheumatoid arthritis and on chronic steroid therapy, experiences sudden chest pain while swimming. She initially attributes it to her arthritis but calls emergency services when she starts feeling nauseous and dizzy. On arrival, she is hypotensive and tachycardic. The patient's ECG is presented below. What is the diagnosis?

• ○ Atrial fibrillation and secondary ST T changes.
• ✓ STEMI and atrial fibrillation
• ○ Right ventricular hypertrophy (RVH)

Question 17

A 48-year-old male, who is a known alcoholic, is brought in by his friends for sudden onset of severe chest pain and vomiting after a heavy drinking session. He has no known history of heart disease. He appears disoriented and his vitals are unstable. An ECG is performed urgently. The patient's ECG is presented below. Which alternatives below are correct?

• ✓ Previous anteroseptal myocardial infarction
• ✓ Intraventricular conduction defect, likely RBBB and LAH
• ✓ Atypical ST segment elevations in inferior limb leads
• ✓ First degree AV block

Explanation. All alternatives are correct. Despite the intraventricular conduction defects, these ST elevations in II, aVF and III are atypical, and in conjunction with ST depression in aVL lead to suspicion of STEMI.

Question 18

A 70-year-old female, with a history of hypertension, experiences sudden, sharp chest pain and collapses during a family gathering. CPR is initiated immediately by family members. On arrival, paramedics find her in cardiac arrest with a shockable rhythm. After successful resuscitation and return of spontaneous circulation (ROSC), an ECG is obtained. The patient's ECG is presented below. What should be the immediate management?

• ✓ Urgent coronary angiography.
• ○ Thrombolysis
• ○ Platelet inhibitors and anticoagulants, admission to CCU / ICU

Question 19

A 65-year-old male with a history of chronic back pain experiences a sudden, intense pain in the middle of his back while lifting groceries. He initially dismisses it as a muscle strain but then develops shortness of breath and mild chest discomfort. He has a history of smoking and his father had a heart attack at 60. On examination, he is tachycardic and appears uncomfortable. The patient's ECG is presented below. What is the diagnosis?

• ✓ STEMI
• ○ NSTEMI
• ○ Limb lead reversal mimicking STEMI