A 55-year-old man comes to the emergency department due to sudden onset of retrosternal chest pain. The pain began 10 hours ago and has been mostly constant, although he describes it as "being bad and then getting a little better." The patient has had no lightheadedness, syncope, or shortness of breath. ECG shows normal sinus rhythm with 2-mm ST-segment elevation in leads V2 to V5. He is taken emergently for cardiac catheterization and undergoes percutaneous coronary intervention with stent placement to the left anterior descending artery. After the procedure, the ST-segment changes improve and he has complete resolution of the chest pain. On the third night, just prior to discharge, he calls for the nurse due to the sudden onset of sharp, retrosternal chest pain. The patient first noticed the pain while turning around in bed; it worsens with deep breathing. Temperature is 37.8 C (100 F), blood pressure is 134/80 mm Hg, heart rate is 108/min, and respirations are 22/min. Physical examination reveals regular heart sounds and clear lung fields. There is a scratchy sound heard during ventricular systole along the left sternal border. Abdominal palpation reveals no localized tenderness. ECG shows sinus tachycardia with Q waves and T-wave inversion in leads V2 to V5.
Which of the following is the most likely cause of this patient's recurrent symptoms?

Question

A 55-year-old man comes to the emergency department due to sudden onset of retrosternal chest pain.  The pain began 10 hours ago and has been mostly constant, although he describes it as "being bad and then getting a little better."  The patient has had no lightheadedness, syncope, or shortness of breath.  ECG shows normal sinus rhythm with 2-mm ST-segment elevation in leads V2 to V5.  He is taken emergently for cardiac catheterization and undergoes percutaneous coronary intervention with stent placement to the left anterior descending artery.  After the procedure, the ST-segment changes improve and he has complete resolution of the chest pain.  On the third night, just prior to discharge, he calls for the nurse due to the sudden onset of sharp, retrosternal chest pain.  The patient first noticed the pain while turning around in bed; it worsens with deep breathing.  Temperature is 37.8 C (100 F), blood pressure is 134/80 mm Hg, heart rate is 108/min, and respirations are 22/min.  Physical examination reveals regular heart sounds and clear lung fields.  There is a scratchy sound heard during ventricular systole along the left sternal border.  Abdominal palpation reveals no localized tenderness.  ECG shows sinus tachycardia with Q waves and T-wave inversion in leads V2 to V5. 
Which of the following is the most likely cause of this patient's recurrent symptoms?

Quizplus · Accepted Answer

Explanation: 11ec2b69_be01_c511_8f63_2997b1d3a77e_MD0005_00 This patient's chest pain is most likely due to peri-infarction pericarditis (PIP), which can occur due to localized inflammation typically <4 days following acute myocardial infarction (MI). Delayed coronary reperfusion following ST-elevation MI (eg, >3 hours from symptom onset) increases the risk of developing PIP. Patients with PIP typically have pleuritic chest pain that worsens with deep inspiration and improves with sitting up. The pain is usually located retrosternally and often radiates posteriorly to the bilateral trapezius ridges (lower portion of the scapulae). Low-grade fever may be present. Cardiac auscultation should reveal a pericardial friction rub that is classically triphasic (heard in atrial systole, ventricular systole, and early ventricular diastole). ECG characteristically shows diffuse PR depression and ST elevation, but these findings are not always present and may be masked by ECG changes from recent MI. diffuse PR depression and ST elevation (Choices A and E) Recurrent myocardial ischemia or infarction is often difficult to distinguish from PIP. However, pleuritic chest pain (worse with position and breathing) and pericardial friction rub, along with the absence of any new ECG changes, are consistent with acute pericarditis. (Choice C) Dressler syndrome (post cardiac injury syndrome) is an immune-mediated pericarditis that can occur several weeks following MI. The symptomatic presentation is similar to PIP, but it would be highly unusual for Dressler syndrome to occur within 2-3 days following MI. (Choice D) Ventricular aneurysm occurs as a late complication, typically weeks to months, after acute MI. It is characterized by ECG findings of persistent ST-segment elevation, along with deep Q waves in the same leads. The usual presentation is progressive left ventricular enlargement causing heart failure, refractory angina, ventricular arrhythmias, or systemic arterial embolization due to mural thrombus. Educational objective: Patients with peri-infarction pericarditis typically have pleuritic chest pain and a pericardial friction rub <4 days following an acute myocardial infarction. The characteristic ECG changes of diffuse PR depression and ST elevation may also be present, but can be masked by ECG changes of recent myocardial infarction. References: 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/23256914)

A 55-Year-Old Man Comes to the Emergency Department Due to Sudden