Internal Medicine Acute Coronary Syndromes Questions and Answers — Questions and Answers
Question 1: A 68-year-old male with a history of hypertension and hyperlipidemia presents with 2 hours of substernal chest pain. An ECG shows ST-segment elevation in leads II, III, and aVF. His blood pressure is 85/50 mmHg, heart rate is 50 bpm, and lungs are clear to auscultation. Jugular venous pressure is elevated. Which of the following is the most appropriate initial management step?
- Administer intravenous nitroglycerin
- Administer a 500 mL bolus of normal saline (Correct answer)
- Administer intravenous metoprolol
- Place an intra-aortic balloon pump
Correct answer: Administer a 500 mL bolus of normal saline
This patient's presentation with an inferior STEMI (ST elevation in II, III, aVF), hypotension, bradycardia, and elevated JVP with clear lungs is highly suggestive of acute right ventricular (RV) infarction. In RV infarction, the right ventricle is stiff and preload-dependent. The primary goal of management is to maintain adequate RV preload to ensure sufficient left ventricular filling and cardiac output. Therefore, the most appropriate initial step is intravenous fluid administration with normal saline. Nitroglycerin and other preload-reducing agents are contraindicated as they can cause profound hypotension. Beta-blockers should be used with caution due to the risk of worsening bradycardia and hypotension. An IABP is not a first-line therapy and is considered for refractory cardiogenic shock.
Question 2: A 55-year-old female is evaluated for an acute coronary syndrome. According to the TIMI risk score for UA/NSTEMI, which of the following patient characteristics is NOT considered a risk factor?
- Age ≥ 65 years
- Known coronary artery disease with >50% stenosis
- Systolic blood pressure < 100 mmHg (Correct answer)
- Aspirin use in the past 7 days
Correct answer: Systolic blood pressure < 100 mmHg
The TIMI risk score for unstable angina/non-ST elevation MI (UA/NSTEMI) includes seven variables: age ≥65 years, ≥3 risk factors for CAD (e.g., hypertension, diabetes, smoking), known CAD with ≥50% stenosis, aspirin use in the past 7 days, severe angina (≥2 episodes in 24 hours), ST deviation ≥0.5 mm, and positive cardiac markers. Systolic blood pressure is not a component of this specific risk score.
Question 3: A 76-year-old male with a history of a transient ischemic attack (TIA) 2 years ago is admitted with an NSTEMI and undergoes percutaneous coronary intervention with placement of a drug-eluting stent. Which of the following P2Y12 inhibitors is contraindicated in this patient?
- Clopidogrel
- Ticagrelor
- Cangrelor
- Prasugrel (Correct answer)
Correct answer: Prasugrel
Prasugrel is contraindicated in patients with a prior history of transient ischemic attack (TIA) or stroke. This is due to an increased risk of significant, sometimes fatal, bleeding, including intracranial hemorrhage, observed in this patient population during clinical trials. The other listed P2Y12 inhibitors do not have this absolute contraindication.
Question 4: A 62-year-old man is brought to the emergency department with severe chest pain. His ECG is consistent with an acute ST-elevation myocardial infarction (STEMI). He admits to using cocaine approximately one hour prior to the onset of his symptoms. He is hypertensive and tachycardic. In addition to aspirin and emergent reperfusion therapy, which of the following is the most appropriate initial medication?
- Intravenous lorazepam (Correct answer)
- Intravenous labetalol
- Intravenous diltiazem
- Intravenous esmolol
Correct answer: Intravenous lorazepam
In patients with cocaine-associated chest pain and ACS, the initial management should focus on benzodiazepines (e.g., lorazepam) to reduce central sympathetic outflow, alleviate anxiety, and decrease myocardial oxygen demand. While the historical concern about using beta-blockers due to 'unopposed alpha-stimulation' has been challenged by recent meta-analyses showing no increased harm, they are not the first-line therapy. Benzodiazepines are the primary treatment to control hypertension and tachycardia in this specific clinical context. Calcium channel blockers like diltiazem can also be used.
Question 5: Five days after an extensive anterior wall myocardial infarction, a 70-year-old female becomes acutely hypotensive and develops respiratory distress. On examination, a new, loud, harsh holosystolic murmur is heard best at the left lower sternal border, accompanied by a palpable thrill. Which of the following is the most likely diagnosis?
- Papillary muscle rupture
- Ventricular free wall rupture
- Ventricular septal rupture (Correct answer)
- Dressler syndrome
Correct answer: Ventricular septal rupture
The clinical presentation of acute hemodynamic deterioration 3-5 days post-MI, coupled with a new, loud, harsh holosystolic murmur at the left lower sternal border and a palpable thrill, is classic for a post-infarction ventricular septal rupture (VSR). Papillary muscle rupture typically presents with a murmur of acute mitral regurgitation best heard at the apex. Ventricular free wall rupture leads to hemopericardium and rapid progression to pulseless electrical activity. Dressler syndrome is a post-MI pericarditis that occurs weeks to months later.
Question 6: A 58-year-old male with NSTEMI undergoes successful PCI with the placement of a new-generation drug-eluting stent in the left anterior descending artery. He has no history of bleeding disorders and is considered at low bleeding risk. According to current ACC/AHA guidelines, what is the minimum recommended duration of dual antiplatelet therapy (DAPT) for this patient?
- 3 months
- 6 months
- 12 months (Correct answer)
- 24 months
Correct answer: 12 months
For patients presenting with an acute coronary syndrome (ACS), including NSTEMI, who are treated with a drug-eluting stent, the standard recommended duration of dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 inhibitor is at least 12 months. While shorter durations may be considered in patients with stable ischemic heart disease or those at high bleeding risk, the standard for ACS is 12 months to reduce the risk of subsequent ischemic events.
