A 65-year-old man is brought to the emergency department due to chest discomfort and diaphoresis that began suddenly an hour ago while he was resting in a chair and watching television. He describes the discomfort as "squeezing"; it is associated with left arm numbness and nausea. En route to the hospital, he was given oral aspirin and sublingual nitroglycerin. The patient has never had similar symptoms and has no medical history. He has smoked a pack of cigarettes daily for the past 40 years. Temperature is 36.9 C (98.4 F), blood pressure is 165/95 mm Hg, pulse is 50/min, and respirations are 18/min. The first and second heart sounds are normal, and a fourth heart sound is heard. The lungs are clear to auscultation. There is no jugular venous distension or pedal edema. A tracing from his initial ECG is shown in the exhibit. Immediate interventions aimed at achieving which of the following goals would most improve this patient's long-term prognosis?

Question

A 65-year-old man is brought to the emergency department due to chest discomfort and diaphoresis that began suddenly an hour ago while he was resting in a chair and watching television.  He describes the discomfort as "squeezing"; it is associated with left arm numbness and nausea.  En route to the hospital, he was given oral aspirin and sublingual nitroglycerin.  The patient has never had similar symptoms and has no medical history.  He has smoked a pack of cigarettes daily for the past 40 years.  Temperature is 36.9 C (98.4 F), blood pressure is 165/95 mm Hg, pulse is 50/min, and respirations are 18/min.  The first and second heart sounds are normal, and a fourth heart sound is heard.  The lungs are clear to auscultation.  There is no jugular venous distension or pedal edema.  A tracing from his initial ECG is shown in the exhibit.  Immediate interventions aimed at achieving which of the following goals would most improve this patient's long-term prognosis?

Quizplus · Accepted Answer

The clinical presentation (chest pain, diaphoresis, arm numbness, nausea) and ECG findings with ST-segment elevation in leads II, III, and aVF are consistent with acute inferior ST-segment elevation myocardial infarction (STEMI) likely due to abrupt right coronary artery occlusion. Prompt restoration of coronary blood flow with primary percutaneous intervention (PCI) or fibrinolysis limits myocardial damage and improves cardiovascular and overall long-term mortality. ST-segment elevation in leads II, III, and aVF Current guidelines recommend the use of primary PCI for any patient with acute STEMI within 90 minutes of the first medical contact in a PCI-capable hospital or within 120 minutes for patients who require transport to a PCI-capable hospital from another hospital. Multiple randomized trials of primary PCI compared to fibrinolysis have shown lower rates of recurrent MI and intracranial hemorrhage and improved survival with primary PCI. (Choice A) There is no evidence of improved long-term outcomes with interventions aimed at decreasing cardiac afterload (eg, nitrates, intra-aortic balloon pump) in patients with acute MI (AMI). Nitrates are administered to relieve chest pain in AMI but should be used cautiously in patients who have right ventricular MI as they can cause hypotension. (Choice B) Early use of beta blockers (within 24 hours) decreases myocardial contractility and can reduce myocardial oxygen demand in AMI. However, immediate use of intravenous beta blockers (before primary PCI) has not been shown to improve clinical outcomes and can exacerbate hemodynamic instability or heart failure. This patient also has a pulse of 50/min and risks bradycardia with beta blocker therapy. (Choice C) Routine prophylactic use of antiarrhythmic therapy to prevent atrial or ventricular arrhythmias in patients with AMI does not improve long-term outcomes and is not recommended. (Choice D) Reperfusion injury refers to myocardial cell damage that occurs due to restoration of blood flow after a sudden ischemic event. No specific therapy has been shown to prevent reperfusion injury following AMI. Educational objective: Prompt recognition and restoration of coronary blood flow with primary percutaneous intervention or fibrinolysis improves cardiovascular and overall long-term mortality in patients with ST-elevation 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/23247304)

A 65-Year-Old Man Is Brought to the Emergency Department Due