A 56-year-old man is brought to the emergency department due to chest pain. An hour ago, he woke up with burning retrosternal severe chest pain accompanied by sweating and left arm numbness. The patient's symptoms improved with aspirin and sublingual nitroglycerin administered by the paramedics; he currently rates his chest pain as 4 on a scale of 10. He has had no nausea, vomiting, or abdominal discomfort. The patient has a history of gastroesophageal reflux disease, diet-controlled diabetes mellitus, and 30-pack-years of smoking. Temperature is 37.3 (99 F), blood pressure is 150/90 mm Hg on the right arm and 145/88 mm Hg on the left arm, and pulse is 95/min and regular. The lungs are clear on auscultation and heart sounds are normal with no murmur or gallop. ECG shows normal sinus rhythm with T-wave inversion in leads V1-V4. The troponin level is normal. Which of the following is the most appropriate next step in management of this patient?

Question

A 56-year-old man is brought to the emergency department due to chest pain.  An hour ago, he woke up with burning retrosternal severe chest pain accompanied by sweating and left arm numbness.  The patient's symptoms improved with aspirin and sublingual nitroglycerin administered by the paramedics; he currently rates his chest pain as 4 on a scale of 10.  He has had no nausea, vomiting, or abdominal discomfort.  The patient has a history of gastroesophageal reflux disease, diet-controlled diabetes mellitus, and 30-pack-years of smoking.  Temperature is 37.3 (99 F), blood pressure is 150/90 mm Hg on the right arm and 145/88 mm Hg on the left arm, and pulse is 95/min and regular.  The lungs are clear on auscultation and heart sounds are normal with no murmur or gallop.  ECG shows normal sinus rhythm with T-wave inversion in leads V1-V4.  The troponin level is normal.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d184_0618_bc81_0928c8937c93_MD0003_00 This patient's clinical presentation - sudden onset of chest discomfort with left arm numbness, diaphoresis, and T-wave inversions in the anterior precordial leads - is consistent with acute coronary syndrome (ACS) due to unstable angina (UA) or non-ST elevation myocardial infarction (NSTEMI). A significant troponin elevation within 6-12 hours differentiates NSTEMI from UA, but acute management of the conditions is the same. The goals include relief of ischemic pain, assessment and maintenance of hemodynamic stability, and prevention of recurrent ischemia and thrombosis. The following pharmacologic agents are used: Antiplatelet agents (eg, aspirin and clopidogrel, aspirin and ticagrelor) and anticoagulant therapy (eg, unfractionated heparin, enoxaparin, bivalirudin) to prevent additional plaque thrombosis or recurrent coronary thrombosis Beta blockers (eg, metoprolol, atenolol) to reduce myocardial oxygen demand and the risk of ventricular arrhythmias Nitrates to reduce myocardial oxygen demand and relieve ischemic pain High-intensity statins (eg, atorvastatin, rosuvastatin) to stabilize atherosclerotic plaques and lower the risk of recurrent ACS (Choice A) Prophylactic antiarrhythmic therapy (other than beta blockers) is not recommended in acute coronary syndrome. However, serum potassium and magnesium should be maintained at normal levels to help prevent arrhythmias. (Choice B) Exercise stress testing is used to evaluate for coronary artery disease in patients with symptoms consistent with stable angina (eg, reproducible chest pain with exertion that resolves with rest). However, a stress test in a patient with probable acute coronary syndrome could cause an extension of myocardial infarction or provoke a life-threatening arrhythmia. This patient's clinical presentation is highly consistent with ACS, so stress testing is not appropriate. (Choice C) Intravenous alteplase (tissue plasminogen activator) is a fibrinolytic agent indicated for the treatment of ACS due to STEMI when timely primary percutaneous revascularization is unavailable. Fibrinolytic therapy is not indicated in ACS due to UA or NSTEMI. (Choice E) Oral proton pump inhibitors are used to treat gastroesophageal reflux disease. The chest pain of myocardial infarction can be similar to that of gastroesophageal reflux disease; however, this patient's ECG findings suggestive of ischemia (eg, anterior precordial T-wave inversion) make ACS more likely. Educational objective: Acute coronary syndrome due to unstable angina or non-ST elevation myocardial infarction is managed with antiplatelet and antithrombotic agents, beta blockers, nitrates, and high-intensity statins. Fibrinolytic therapy is not used in patients with non-ST elevation acute coronary syndrome. References: 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/25249586)

A 56-Year-Old Man Is Brought to the Emergency Department Due