A 56-year-old patient developed excruciating chest discomfort in the past 72 hours, relieved by GTN spray. Troponin I is normal, and the ECG shows features of left ventricular hypertrophy (LVH) with T wave flattening. The patient is already on statins, aspirin, and metoprolol 50 mg . What is the next best step in management?
Q2
A 78-year-old male with a 35-pack-year smoking history, hyperlipidemia, and peripheral vascular disease is at home eating dinner with his wife when he suddenly has acute onset, crushing chest pain. He lives in a remote rural area, and, by the time the paramedics arrive 30 minutes later, he is pronounced dead. What is the most likely cause of this patient's death?
Q3
A 57-year-old man is brought to the emergency department after having chest pain for the last hour. He rates his pain as 8/10, dull in character, and says it is associated with sweating and shortness of breath. He has a history of diabetes and hypercholesterolemia. His current medication list includes amlodipine, aspirin, atorvastatin, insulin, and esomeprazole. He has smoked 2 packs of cigarettes per day for the past 25 years. His blood pressure is 98/66 mm Hg, pulse is 110/min, oxygen saturation is 94% on room air, and BMI is 31.8 kg/m2. His lungs are clear to auscultation. An electrocardiogram (ECG) is shown below. The patient is given 325 mg of oral aspirin and sublingual nitroglycerin. What is the most appropriate next step in the management of this condition?
Q4
A 73-year-old woman arrives at the emergency department due to intense central chest pain for 30 minutes this morning. She says the pain was cramping in nature and radiated down her left arm. She has a history of atrial fibrillation and type 2 diabetes mellitus. Her pulse is 98/min, respiratory rate is 19/min, temperature is 36.8°C (98.2°F), and blood pressure is 160/91 mm Hg. Cardiovascular examination shows no abnormalities. ECG is shown below. Which of the following biochemical markers would most likely be elevated and remain elevated for a week after this acute event?
Q5
A 55-year-old woman is brought to the emergency department by her husband because of chest pain and a cough productive of blood-tinged sputum that started 1 hour ago. Two days ago, she returned from a trip to China. She has smoked 1 pack of cigarettes daily for 35 years. Her only home medication is oral hormone replacement therapy for postmenopausal hot flashes. Her pulse is 123/min and blood pressure is 91/55 mm Hg. Physical examination shows distended neck veins. An ECG shows sinus tachycardia, a right bundle branch block, and T-wave inversion in leads V5–V6. Despite appropriate lifesaving measures, the patient dies. Examination of the lung on autopsy shows a large, acute thrombus in the right pulmonary artery. Based on the autopsy findings, which of the following is the most likely origin of the thrombus?
Q6
A 60-year-old African American gentleman presents to the emergency department with sudden onset "vice-like" chest pain, diaphoresis, and pain radiating to his left shoulder. He has ST elevations on his EKG and elevated cardiac enzymes. Concerning his current pathophysiology, which of the following changes would you expect to see in this patient?
Q7
A 56-year-old man comes to the emergency department because of chest pain. The pain occurs intermittently in 5-minute episodes. It is not conclusively brought on by exertion and sometimes occurs at rest. He has a history of hyperlipidemia and takes a high-dose statin daily. His father died of lung cancer at the age of 67 years and his mother has type 2 diabetes. He smokes a pack of cigarettes daily and does not drink alcohol. His temperature is 37°C (98.8°F), pulse is 88/min, and blood pressure is 124/72 mm Hg. Cardiac examination shows no abnormalities. He has no chest wall tenderness and pain is not reproduced with palpation. While waiting for laboratory results, he has another episode of chest pain. During this event, an ECG shows ST elevations in leads II, III, and aVF that are > 1 mm. Thirty minutes later, a new ECG shows no abnormalities. Troponin I level is 0.008 ng/mL (normal value < 0.01 ng/mL). Cardiac angiography is performed and shows a 30% blockage of the proximal right circumflex artery and 10% blockage in the distal left circumflex artery. This patient's condition is most closely associated with which of the following?
Q8
A 54-year-old woman is brought to the emergency department because of a 2-hour history of nausea and retrosternal chest pain. She has a 15-year history of type 2 diabetes mellitus. Her current medications include atorvastatin, metformin, and lisinopril. She is diaphoretic. Her serum troponin level is 3.0 ng/mL (N: < 0.04). She undergoes cardiac catheterization. A photograph of coronary angiography performed prior to percutaneous coronary intervention is shown. An acute infarct associated with the finding on angiography is most likely to manifest with ST elevations in which of the following leads on ECG?
Q9
Two days after coronary artery stent placement for a posterior myocardial infarction, a 70-year-old woman complains of difficulty breathing and retrosternal chest pain. She has a history of atrial fibrillation, for which she takes verapamil. Following stent placement, the patient was started on aspirin and clopidogrel. She appears to be in acute distress and is disoriented. Respirations are 22/min. Pulse oximetry on room air shows an oxygen saturation of 80%. Diffuse crackles are heard on auscultation of the chest. The patient is intubated and mechanical ventilation is started. Shortly afterwards, she becomes unresponsive. Heart sounds are inaudible and her carotid pulses are not palpable. The cardiac monitor shows normal sinus rhythm with T-wave inversion. Which of the following is the most appropriate next step in management?
Q10
A 57-year-old man presents to his primary care provider because of chest pain for the past 3 weeks. The chest pain occurs after climbing more than 2 flights of stairs or walking for more than 10 minutes. His symptoms remain for an average of 30 minutes despite rest, but they eventually remit. He is obese, has a history of type 2 diabetes mellitus, and has smoked 15–20 cigarettes a day for the past 25 years. His father died from a myocardial infarction at 52 years of age. His vital signs reveal a temperature of 36.7°C (98.0°F), blood pressure of 145/93 mm Hg, and a heart rate of 85/min. The physical examination is unremarkable. Which of the following is consistent with unstable angina?
ACS US Medical PG Practice Questions and MCQs
Question 1: A 56-year-old patient developed excruciating chest discomfort in the past 72 hours, relieved by GTN spray. Troponin I is normal, and the ECG shows features of left ventricular hypertrophy (LVH) with T wave flattening. The patient is already on statins, aspirin, and metoprolol 50 mg . What is the next best step in management?
A. LMWH (Low Molecular Weight Heparin)
B. Increase beta blocker dose
C. IV NTG Drip
D. Add Clopidogrel (Correct Answer)
E. Arrange urgent coronary angiography
Explanation: ***Add Clopidogrel***
- The patient presents with **unstable angina** (chest discomfort relieved by GTN, normal troponin, and ECG changes indicative of ischemia) and is already on aspirin, statins, and a beta-blocker.
- Adding **clopidogrel** (or another P2Y12 inhibitor) is crucial for **dual antiplatelet therapy (DAPT)**, which is a cornerstone in the management of unstable angina/NSTEMI to prevent further thrombotic events.
- This is the **immediate next step** to optimize medical therapy before considering invasive strategies.
*LMWH (Low Molecular Weight Heparin)*
- While **anticoagulation** is important in acute coronary syndromes and would be appropriate to add, the question asks for the **next best step** given the patient's existing management.
- LMWH would typically be added alongside DAPT, but establishing dual antiplatelet therapy takes priority.
*Increase beta blocker dose*
- The patient is already on metoprolol 50 mg, and while **titrating beta-blockers** is important for symptom control and reducing myocardial oxygen demand, the immediate priority in unstable angina is to address the underlying thrombotic process with DAPT.
- Beta-blocker optimization can be done after ensuring adequate antiplatelet therapy.
*IV NTG Drip*
- **Intravenous nitroglycerin (IV NTG)** is used to relieve ongoing chest pain and reduce preload/afterload, especially in severe or refractory symptoms.
- However, the patient's chest discomfort was already **relieved by GTN spray**, indicating that immediate pain control with IV NTG is not the most urgent next step compared to preventing further thrombotic events with DAPT.
*Arrange urgent coronary angiography*
- While **coronary angiography** is indicated in high-risk unstable angina, the immediate next step is to **optimize medical management** with dual antiplatelet therapy.
- Angiography timing depends on risk stratification; in a stable patient already on aspirin, beta-blockers, and statins, adding clopidogrel first ensures optimal antiplatelet coverage before any invasive procedure.
- Early invasive strategy (angiography within 24-72 hours) would be appropriate after medical stabilization.
Question 2: A 78-year-old male with a 35-pack-year smoking history, hyperlipidemia, and peripheral vascular disease is at home eating dinner with his wife when he suddenly has acute onset, crushing chest pain. He lives in a remote rural area, and, by the time the paramedics arrive 30 minutes later, he is pronounced dead. What is the most likely cause of this patient's death?
A. Ventricular septum rupture
B. Heart block
C. Ventricular fibrillation (Correct Answer)
D. Chordae tendineae rupture
E. Cardiac tamponade
Explanation: ***Ventricular fibrillation***
- This is the most common cause of sudden cardiac death in the setting of acute **myocardial infarction** (MI), especially in the initial hours.
- The sudden onset of **crushing chest pain** in a patient with significant cardiac risk factors strongly suggests an acute MI, leading to electrical instability.
*Ventricular septum rupture*
- A ventricular septum rupture is a mechanical complication of MI that typically occurs **3 to 5 days post-infarction**, not acutely.
- It would present with a new **holosystolic murmur** and signs of heart failure (e.g., hypotension, pulmonary edema), symptoms not described here.
*Heart block*
- While heart blocks can occur during MI, they usually cause **bradycardia** and syncope rather than sudden death from acute crushing chest pain, unless they progress to asystole.
- A heart block alone is less likely to be the immediate cause of sudden death in this scenario compared to a severe arrhythmia.
*Chordae tendineae rupture*
- Chordae tendineae rupture is also a mechanical complication of MI that usually occurs **2 to 7 days post-infarction** and leads to severe **mitral regurgitation**.
- It would present with acute pulmonary edema and a new harsh holosystolic murmur, which would develop after the initial chest pain, not as the immediate cause of sudden demise.
*Cardiac tamponade*
- Cardiac tamponade from a **free wall rupture** is a catastrophic complication that typically occurs 1 to 3 days after MI.
- It presents with **Beck's triad** (hypotension, jugular venous distension, muffled heart sounds) and pulsus paradoxus, which are not described in this acute, sudden death scenario.
Question 3: A 57-year-old man is brought to the emergency department after having chest pain for the last hour. He rates his pain as 8/10, dull in character, and says it is associated with sweating and shortness of breath. He has a history of diabetes and hypercholesterolemia. His current medication list includes amlodipine, aspirin, atorvastatin, insulin, and esomeprazole. He has smoked 2 packs of cigarettes per day for the past 25 years. His blood pressure is 98/66 mm Hg, pulse is 110/min, oxygen saturation is 94% on room air, and BMI is 31.8 kg/m2. His lungs are clear to auscultation. An electrocardiogram (ECG) is shown below. The patient is given 325 mg of oral aspirin and sublingual nitroglycerin. What is the most appropriate next step in the management of this condition?
A. Observation
B. Echocardiography
C. Percutaneous coronary intervention (Correct Answer)
D. Enoxaparin
E. Metoprolol
Explanation: ***Percutaneous coronary intervention***
- The ECG shows significant **ST-segment elevation in leads V2-V6, I, and aVL**, indicating an anterior and lateral ST-elevation myocardial infarction (STEMI).
- Given the ongoing chest pain and ECG findings, **emergent percutaneous coronary intervention (PCI)** is the most appropriate next step to restore blood flow and minimize myocardial damage.
*Observation*
- This patient is experiencing an acute STEMI, which requires immediate and aggressive intervention, not just observation.
- Delaying treatment significantly increases the risk of large infarction, heart failure, and death.
*Echocardiography*
- While echocardiography is useful in evaluating myocardial function and assessing complications after an MI, it is not the immediate priority in a patient with ongoing STEMI.
- The focus must be on prompt reperfusion, usually within 90 minutes of first medical contact.
*Enoxaparin*
- Enoxaparin is an anticoagulant often used in acute coronary syndrome management, including STEMI.
- However, it is an adjunctive therapy to reperfusion, and not the definitive next step for someone presenting with an acute STEMI.
*Metoprolol*
- Beta-blockers like metoprolol can be beneficial in STEMI to reduce myocardial oxygen demand and modify ventricular remodeling.
- However, they are typically given after reperfusion therapy is initiated and the patient is hemodynamically stable, especially in the setting of hypotension (98/66 mmHg here).
Question 4: A 73-year-old woman arrives at the emergency department due to intense central chest pain for 30 minutes this morning. She says the pain was cramping in nature and radiated down her left arm. She has a history of atrial fibrillation and type 2 diabetes mellitus. Her pulse is 98/min, respiratory rate is 19/min, temperature is 36.8°C (98.2°F), and blood pressure is 160/91 mm Hg. Cardiovascular examination shows no abnormalities. ECG is shown below. Which of the following biochemical markers would most likely be elevated and remain elevated for a week after this acute event?
A. Alanine aminotransferase
B. Creatinine-kinase MB
C. Troponin I (Correct Answer)
D. Aspartate transaminase
E. Lactate dehydrogenase (LDH)
Explanation: ***Troponin I***
- **Troponin I** is a highly specific cardiac marker that is elevated in myocardial injury and can remain elevated for **up to two weeks** after the event.
- Its elevation correlates with the degree of myocardial damage, making it a critical marker for diagnosing **acute coronary syndrome**.
*Alanine aminotransferase*
- Primarily a liver enzyme, its elevation does not directly indicate myocardial injury and does not remain elevated for **an extended period** in the context of acute chest pain.
- Its utility is mainly in **liver function assessment**, not in acute coronary events.
*Creatinine-kinase MB*
- While it indicates myocardial damage, **CK-MB** typically returns to baseline levels within **48-72 hours** following the acute event, unlike troponin.
- It is less specific than troponin for cardiac injury, especially in cases of skeletal muscle injury.
*Aspartate transaminase*
- Similar to alanine aminotransferase, it is not a **specific marker for myocardial injury** and is elevated in various **hepatic conditions**.
- It also does not remain elevated for a sufficient duration to be considered useful in diagnosing myocardial infarction.
*Lactate dehydrogenase (LDH)*
- Although LDH is released during myocardial injury and remains elevated for **10-14 days** (similar to troponin), it **lacks specificity** for cardiac tissue.
- LDH can be elevated in many conditions, including **hemolysis, liver disease, muscle injury, and various malignancies**, making it less reliable for diagnosing acute coronary syndrome.
- While historically used as a late marker for MI, **troponin has replaced LDH** due to its superior cardiac specificity.
Question 5: A 55-year-old woman is brought to the emergency department by her husband because of chest pain and a cough productive of blood-tinged sputum that started 1 hour ago. Two days ago, she returned from a trip to China. She has smoked 1 pack of cigarettes daily for 35 years. Her only home medication is oral hormone replacement therapy for postmenopausal hot flashes. Her pulse is 123/min and blood pressure is 91/55 mm Hg. Physical examination shows distended neck veins. An ECG shows sinus tachycardia, a right bundle branch block, and T-wave inversion in leads V5–V6. Despite appropriate lifesaving measures, the patient dies. Examination of the lung on autopsy shows a large, acute thrombus in the right pulmonary artery. Based on the autopsy findings, which of the following is the most likely origin of the thrombus?
A. Iliac vein (Correct Answer)
B. Subclavian vein
C. Renal vein
D. Great saphenous vein
E. Posterior tibial vein
Explanation: ***Iliac vein***
- The iliac vein is a common source of **deep vein thrombosis (DVT)**, which can embolize to the pulmonary arteries, especially with risk factors like prolonged travel and hormone replacement therapy. This type of thrombus is often large enough to cause significant hemodynamic instability and death, as seen clinically.
- The patient's presentation with **chest pain**, **blood-tinged sputum**, **hypotension**, **tachycardia**, **distended neck veins**, and ECG changes (right bundle branch block, T-wave inversion in V5-V6 suggesting **right heart strain**) is classic for a massive pulmonary embolism (PE) originating from a large venous thrombosis, most commonly from the iliofemoral system.
*Subclavian vein*
- While subclavian vein thrombosis can occur, it's typically associated with **central venous catheters** or **thoracic outlet syndrome**. These risk factors are not mentioned in the patient's history.
- Thrombi from this location are a less common cause of **massive pulmonary embolism** compared to lower extremity deep vein thrombosis.
*Renal vein*
- **Renal vein thrombosis** is usually associated with conditions like nephrotic syndrome, malignancy, or hypercoagulable states, and often presents with flank pain or hematuria.
- While it can lead to PE, it's a less common source for a **massive clot** causing acute cardiopulmonary collapse than lower extremity veins.
*Great saphenous vein*
- The great saphenous vein is part of the **superficial venous system**. Superficial thrombophlebitis is generally a benign condition with a low risk of pulmonary embolism.
- When superficial clots do extend into the deep system, they can cause PE, but the primary origin of a massive, fatal PE is typically from the **deep veins**.
*Posterior tibial vein*
- The posterior tibial vein is a **deep vein**, and thrombosis here can certainly lead to PE. However, it is a smaller vein compared to the iliac veins.
- While a posterior tibial vein clot *could* embolize, a **massive pulmonary embolism** resulting in acute death is more frequently caused by larger thrombi from the more proximal, wider deep veins like the iliac or femoral veins.
Question 6: A 60-year-old African American gentleman presents to the emergency department with sudden onset "vice-like" chest pain, diaphoresis, and pain radiating to his left shoulder. He has ST elevations on his EKG and elevated cardiac enzymes. Concerning his current pathophysiology, which of the following changes would you expect to see in this patient?
A. No change in cardiac output; decreased venous return
B. Increased cardiac output; increased systemic vascular resistance
C. Decreased cardiac output; increased systemic vascular resistance (Correct Answer)
D. Increased cardiac output; decreased systemic vascular resistance
E. Decreased cardiac output; decreased venous return
Explanation: ***Decreased cardiac output; increased systemic vascular resistance***
- The patient's symptoms (chest pain, diaphoresis, ST elevations, elevated cardiac enzymes) are classic for an **acute myocardial infarction (MI)**, which directly impairs the heart's pumping function, leading to **decreased cardiac output**.
- In response to decreased cardiac output and reduced tissue perfusion, the body activates the **sympathetic nervous system** and **renin-angiotensin-aldosterone system**, causing **vasoconstriction** and thus **increased systemic vascular resistance** to maintain blood pressure.
*No change in cardiac output; decreased venous return*
- An acute MI significantly compromises the heart's ability to pump blood, meaning **cardiac output will almost certainly change** (decrease).
- While venous return might be affected, it's not the primary compensatory mechanism often leading to **decreased CO** in acute MI, which is largely due to impaired systolic function.
*Increased cardiac output; increased systemic vascular resistance*
- **Increased cardiac output** is highly unlikely in the context of an acute myocardial infarction because the heart muscle is damaged and unable to pump effectively.
- While **increased systemic vascular resistance** occurs as a compensatory mechanism, it's in response to a failed heart, not one that is effectively increasing its output.
*Increased cardiac output; decreased systemic vascular resistance*
- Both **increased cardiac output** and **decreased systemic vascular resistance** are typically signs of a hyperdynamic state (e.g., sepsis in its early stages) or vasodilation, which is contrary to the pathophysiology of an MI.
- An MI causes **cardiac dysfunction** and **compensatory vasoconstriction**, not increased output and vasodilation.
*Decreased cardiac output; decreased venous return*
- While **decreased cardiac output** is expected, **decreased venous return** is not the primary or most impactful immediate systemic response; the body often tries to maintain venous return initially to optimize filling pressures, although severe MI can eventually lead to overall circulatory collapse.
- The more prominent and immediate compensatory mechanism for a failing heart is often **increased systemic vascular resistance** to maintain perfusion pressure.
Question 7: A 56-year-old man comes to the emergency department because of chest pain. The pain occurs intermittently in 5-minute episodes. It is not conclusively brought on by exertion and sometimes occurs at rest. He has a history of hyperlipidemia and takes a high-dose statin daily. His father died of lung cancer at the age of 67 years and his mother has type 2 diabetes. He smokes a pack of cigarettes daily and does not drink alcohol. His temperature is 37°C (98.8°F), pulse is 88/min, and blood pressure is 124/72 mm Hg. Cardiac examination shows no abnormalities. He has no chest wall tenderness and pain is not reproduced with palpation. While waiting for laboratory results, he has another episode of chest pain. During this event, an ECG shows ST elevations in leads II, III, and aVF that are > 1 mm. Thirty minutes later, a new ECG shows no abnormalities. Troponin I level is 0.008 ng/mL (normal value < 0.01 ng/mL). Cardiac angiography is performed and shows a 30% blockage of the proximal right circumflex artery and 10% blockage in the distal left circumflex artery. This patient's condition is most closely associated with which of the following?
A. Peripheral artery disease
B. Hypertension
C. Type 2 diabetes mellitus
D. Stroke
E. Prinzmetal's angina (Correct Answer)
Explanation: ***Prinzmetal's angina***
- The patient's presentation with **recurrent chest pain at rest**, transient **ST elevations** during pain, normal troponin, and mild coronary artery blockages despite risk factors is classic for **Prinzmetal's (variant) angina**.
- This condition is caused by **coronary artery spasm**, leading to temporary myocardial ischemia, which resolves as the spasm relaxes.
*Peripheral artery disease*
- This condition is caused by **atherosclerosis** affecting arteries outside of the heart, most commonly in the legs, leading to symptoms like **claudication** (leg pain with exertion).
- While the patient has risk factors for atherosclerosis, his primary symptoms and ECG findings are not consistent with peripheral artery disease.
*Hypertension*
- Hypertension is a chronic medical condition characterized by persistently elevated **blood pressure**.
- While it is a **risk factor for coronary artery disease**, it does not explain the transient ST elevations and episodes of chest pain at rest seen in this patient.
*Type 2 diabetes mellitus*
- This is a metabolic disorder characterized by **high blood glucose** due to insulin resistance and/or inadequate insulin production.
- While **diabetes is a significant risk factor for cardiovascular disease**, it is the mother's history, not the patient's, and does not directly explain the specific presentation of transient ischemic chest pain.
*Stroke*
- A stroke occurs when the **blood supply to part of the brain is interrupted or reduced**, depriving brain tissue of oxygen and nutrients.
- The patient's symptoms are entirely cardiac in nature (chest pain, ECG changes) and do not suggest a **neurological event** such as a stroke.
Question 8: A 54-year-old woman is brought to the emergency department because of a 2-hour history of nausea and retrosternal chest pain. She has a 15-year history of type 2 diabetes mellitus. Her current medications include atorvastatin, metformin, and lisinopril. She is diaphoretic. Her serum troponin level is 3.0 ng/mL (N: < 0.04). She undergoes cardiac catheterization. A photograph of coronary angiography performed prior to percutaneous coronary intervention is shown. An acute infarct associated with the finding on angiography is most likely to manifest with ST elevations in which of the following leads on ECG?
A. V3R–V6R
B. I, aVR
C. V1–V6 (Correct Answer)
D. II, III, and aVF
E. V7–V9
Explanation: ***V1–V6***
- The angiography shows a significant occlusion in the **left anterior descending (LAD) artery**
- LAD occlusion causes **anterior wall myocardial infarction**
- Anterior MI manifests with **ST elevations in precordial leads V1–V6**
- This is the classic ECG pattern for LAD territory infarction
*V3R–V6R*
- These right-sided precordial leads indicate **right ventricular infarction**
- RV infarction is associated with **proximal right coronary artery (RCA) occlusion**
- Not consistent with the LAD occlusion shown in the angiography
*I, aVR*
- Lead **aVR ST elevation** (especially >1 mm or greater than V1) suggests **left main coronary artery occlusion** or severe multi-vessel disease
- This pattern typically shows widespread ST depression in other leads
- Does not specifically indicate isolated LAD occlusion
*II, III, and aVF*
- ST elevations in these inferior leads indicate **inferior wall myocardial infarction**
- Inferior MI is caused by **right coronary artery (RCA)** occlusion (80%) or left circumflex artery (20%)
- Not associated with LAD occlusion
*V7–V9*
- These posterior leads indicate **posterior wall myocardial infarction**
- Posterior MI results from **left circumflex artery** or dominant RCA occlusion
- Not the primary finding with LAD occlusion
Question 9: Two days after coronary artery stent placement for a posterior myocardial infarction, a 70-year-old woman complains of difficulty breathing and retrosternal chest pain. She has a history of atrial fibrillation, for which she takes verapamil. Following stent placement, the patient was started on aspirin and clopidogrel. She appears to be in acute distress and is disoriented. Respirations are 22/min. Pulse oximetry on room air shows an oxygen saturation of 80%. Diffuse crackles are heard on auscultation of the chest. The patient is intubated and mechanical ventilation is started. Shortly afterwards, she becomes unresponsive. Heart sounds are inaudible and her carotid pulses are not palpable. The cardiac monitor shows normal sinus rhythm with T-wave inversion. Which of the following is the most appropriate next step in management?
A. Synchronized cardioversion
B. Coronary angiography
C. Unsynchronized cardioversion
D. Intravenous epinephrine therapy
E. Chest compressions (Correct Answer)
Explanation: ***Chest compressions***
- The patient presents with **pulselessness** despite a **normal sinus rhythm on the monitor** (pulseless electrical activity or PEA). In PEA, the immediate intervention is **high-quality chest compressions** as per ACLS guidelines.
- The preceding events (difficulty breathing, chest pain, disorientation, hypoxemia, diffuse crackles, and sudden unresponsiveness with unpalpable pulses) point towards acute cardiovascular collapse likely due to **cardiac tamponade** or other cause of obstructive shock, but the immediate response to pulselessness is compressions.
*Synchronized cardioversion*
- This is indicated for patients who are **unstable with a perfusing tachyarrhythmia**, such as unstable atrial fibrillation with rapid ventricular response or ventricular tachycardia with a pulse.
- The patient has no palpable pulses and exhibits **pulseless electrical activity (PEA)**, not a perfusing tachyarrhythmia, making synchronized cardioversion inappropriate.
*Coronary angiography*
- This is a diagnostic and interventional procedure used to assess and treat **coronary artery disease** or stent thrombosis.
- While post-stent complications are a concern, the patient is in **cardiac arrest (PEA)**, making immediate diagnostic angiography unfeasible and not the priority life-saving intervention.
*Unsynchronized cardioversion*
- Also known as **defibrillation**, this is indicated for **ventricular fibrillation (VF)** or **pulseless ventricular tachycardia (pVT)**.
- The cardiac monitor shows a **normal sinus rhythm**, not VF or pVT, therefore unsynchronized cardioversion is not indicated.
*Intravenous epinephrine therapy*
- Epinephrine is a **vasopressor** used during cardiac arrest to improve coronary and cerebral perfusion.
- While epinephrine is part of the **ACLS algorithm for PEA**, it is given *after* initiating chest compressions, not as the very first step in a pulseless patient.
Question 10: A 57-year-old man presents to his primary care provider because of chest pain for the past 3 weeks. The chest pain occurs after climbing more than 2 flights of stairs or walking for more than 10 minutes. His symptoms remain for an average of 30 minutes despite rest, but they eventually remit. He is obese, has a history of type 2 diabetes mellitus, and has smoked 15–20 cigarettes a day for the past 25 years. His father died from a myocardial infarction at 52 years of age. His vital signs reveal a temperature of 36.7°C (98.0°F), blood pressure of 145/93 mm Hg, and a heart rate of 85/min. The physical examination is unremarkable. Which of the following is consistent with unstable angina?
A. Dyspnea on exertion
B. ST segment depression on ECG
C. Rales on auscultation
D. Symptoms present for 30 minutes despite rest (Correct Answer)
E. S3 on auscultation
Explanation: ***Symptoms present for 30 minutes despite rest***
- **Unstable angina** is characterized by chest pain that is new in onset, occurs at rest, or is more severe, prolonged, or frequent than previously experienced.
- The persistence of symptoms for **30 minutes despite rest** indicates a more severe and prolonged ischemic event, which is consistent with unstable angina.
*Dyspnea on exertion*
- While **dyspnea on exertion** can be a symptom of coronary artery disease, it is not specific to unstable angina and can be seen in stable angina or other cardiac/pulmonary conditions.
- It describes the nature of the exertion, but not the **severity or duration** of the chest pain episode itself, which is key for unstable angina.
*ST segment depression on ECG*
- **ST segment depression** indicates myocardial ischemia and can be present in both stable and unstable angina.
- It does not, by itself, differentiate between the two, as **unstable angina** is primarily a clinical diagnosis based on the change in symptom pattern.
*Rales on auscultation*
- **Rales** suggest pulmonary congestion, often seen in **heart failure** or significant myocardial dysfunction.
- While severe ischemia can lead to heart failure, rales are not a typical or primary symptom used to define unstable angina.
*S3 on auscultation*
- An **S3 heart sound** is a sign of ventricular dysfunction and is typically associated with **heart failure**, often indicating increased left ventricular end-diastolic pressure.
- Like rales, it's a sign of myocardial damage or stress, but not a defining characteristic of **unstable angina** itself.
