Free Questions and Answers for All Medical Students all over the World
10 USMLE Cardiology Quick Review Questions with Answers (Set 2)
These 10 quick USMLE review questions test high-yield facts that show up again and again on the exam: MI management, coronary anatomy, troponin, thrombolysis contraindications, hypertrophic cardiomyopathy, tetralogy of Fallot, left main disease, necrosis in MI and PDA closure. Each question includes the correct answer.
Written by Dr. Ray Makar, MD, author of the Repeated USMLE Questions eBook series.
How to use this page: read the question, pick your answer, then tap Show Answer and Explanation.
Questions
Question 1. A patient presents to the ER with an acute myocardial infarction. After taking aspirin and oxygen, what is the next step of action?
A- Administer metoprolol
B- Check cardiac biomarkers
C- Initiate perfusion therapy
D- Send for echocardiography
C- Initiate perfusion therapy- If a patient is already diagnosed with acute myocardial infarction and has received aspirin and oxygen, the next immediate and life-saving step is to begin reperfusion therapy (PCI if available, or thrombolytics if PCI is not immediately available). Metoprolol, biomarkers, and echocardiography are important—but none take priority over restoring coronary blood flow.
The correct answer is C
Question 2. Which of the following arteries is the most common site of coronary artery occlusion?
A- Left anterior descending artery
B- Left circumflex artery
C- Posterior descending artery
D- Right coronary artery
A- Left anterior descending artery- The left anterior descending (LAD) artery is the most commonly occluded coronary artery and is often called the “widowmaker” because obstruction can lead to extensive anterior wall myocardial infarction.
The correct answer is A
Question 3. Which of the following is the most sensitive test for myocardial infarction?
C- Troponin I- Troponin-I is the most sensitive and specific biomarker for diagnosing myocardial infarction. CK-MB and LDH are less sensitive, and Troponin-C is not used for MI diagnosis.
The correct answer is C
Question 4. Which of the following is an absolute contraindication of fibrinolytic therapy in MI?
A- History of diabetes
B- History of ischemic stroke 4 years ago
C- History of hemorrhagic stroke 9 years ago
D- History of hypertension
C- History of hemorrhagic stroke 9 years ago- A previous hemorrhagic stroke, no matter how long ago, is an absolute contraindication to fibrinolytic therapy due to the high risk of fatal intracranial bleeding. Ischemic stroke more than 3 months ago, diabetes, and hypertension are not absolute contraindications.
The correct answer is C
Question 5. Which one of the following is the best first step of action for a case of posterior myocardial infarction?
A- Aspirin 325 mg administration- In any suspected myocardial infarction — including posterior MI — the very first and most important immediate step is to give chewable aspirin (325 mg) to inhibit platelet aggregation and limit clot progression. Reperfusion therapy (like tPA) comes after initial stabilization. Beta-blockers (like metoprolol) are not the first step and may be harmful in some MI settings. A stress test is never done during an acute MI.
The correct answer is A
Question 6. A young man complains of syncope, dyspnea and chest pain after exercise. A crescendo-decrescendo systolic murmur is heard over the left sternal border without radiation. What is the most likely etiology?
D- Hypertrophic cardiomyopathy- Hypertrophic cardiomyopathy typically presents in young patients with syncope, dyspnea, and chest pain during exercise. The murmur is a crescendo–decrescendo systolic murmur best heard at the left sternal border, without carotid radiation, as seen in aortic stenosis.
The correct answer is D
Question 7. Which of the following is not a feature of Tetralogy of Fallot?
A- Atrial septal defect-
Tetralogy of Fallot consists of four classic defects:
Ventricular septal defect
Overriding aorta
Pulmonary stenosis
Right ventricular hypertrophy
An atrial septal defect is not part of the tetralogy.
The correct answer is A
Question 8. Which of the following management plans is recommended for a case of myocardial infarction with 70% main left stenosis?
A- Coronary artery bypass graft- A left main coronary artery stenosis of 70% is a high-risk, life-threatening lesion. The recommended management is urgent CABG, which provides better survival compared to PCI for significant left main disease. Pharmacologic therapy alone and PCI/PTCA are inadequate for a lesion of this severity.
The correct answer is A
Question 9. Which one of the following types of necrosis is most likely associated with myocardial infarction?
B- Coagulative- Myocardial infarction leads to coagulative necrosis, characterized by preserved tissue architecture with loss of nuclei and increased eosinophilia. Caseous necrosis is seen in tuberculosis, liquefactive in the brain and abscesses, and fibrinoid in immune-mediated vascular injury.
The correct answer is B
Question 10. Which one of the following substances induces the closure of the patent ductus arteriosus?
A- Estradiol
B- Ibuprofen
C- Indomethacin
D- Prostaglandin E
C- Indomethacin- Indomethacin promotes closure of a patent ductus arteriosus by inhibiting prostaglandin synthesis. Prostaglandin E keeps the ductus open, and ibuprofen can also help but indomethacin is the classic and most effective choice.
The correct answer is C
High-yield points from this set
The LAD is the most commonly occluded coronary artery.
Troponin I is the most sensitive and specific marker of MI.
Any prior hemorrhagic stroke is an absolute contraindication to thrombolysis.
Indomethacin closes a patent ductus arteriosus; prostaglandin E keeps it open.