A 64-year-old man comes to the emergency department due to intermittent, burning midline chest pain over the last 2 hours. He has never had similar pain. The patient's medical history includes hypertension and hyperlipidemia. An immediate ECG reveals sinus rhythm with ST-segment elevations in leads II, III, and aVF. Temperature is 37.8 C (99.7 F), blood pressure is 115/70 mm Hg, pulse is 65/min, and respirations are 15/min. He is given sublingual nitroglycerin, and the on-call cardiologist is notified. Several minutes later, the patient reports lightheadedness and extreme weakness. His repeat blood pressure is 75/50 mm Hg and pulse is 85/min. The patient is diaphoretic and his extremities are cold. Jugular venous pulse is elevated in the semirecumbent position. On auscultation, the lungs are clear and no murmurs are heard. Which of the following is the best next step in management of this patient?

Question

A 64-year-old man comes to the emergency department due to intermittent, burning midline chest pain over the last 2 hours.  He has never had similar pain.  The patient's medical history includes hypertension and hyperlipidemia.  An immediate ECG reveals sinus rhythm with ST-segment elevations in leads II, III, and aVF.  Temperature is 37.8 C (99.7 F), blood pressure is 115/70 mm Hg, pulse is 65/min, and respirations are 15/min.  He is given sublingual nitroglycerin, and the on-call cardiologist is notified.  Several minutes later, the patient reports lightheadedness and extreme weakness.  His repeat blood pressure is 75/50 mm Hg and pulse is 85/min.  The patient is diaphoretic and his extremities are cold.  Jugular venous pulse is elevated in the semirecumbent position.  On auscultation, the lungs are clear and no murmurs are heard.  Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

11ec25c8_d17d_7663_bc81_f97d7984b342_MD0003_00 This patient with chest pain and ECG demonstrating ST-segment elevation in the inferior leads has an acute inferior wall ST-segment elevation myocardial infarction (STEMI); inferior wall MI (usually due to occlusion of the right coronary artery) commonly involves the right ventricle. ST-segment elevation in the inferior leads Right ventricular myocardial infarction (RVMI) behaves differently than left ventricular myocardial infarction (LVMI). Acute RV contractile dysfunction causes abruptly increased RV preload with RV dilation and jugular venous distension (JVD), and the failing RV is unable to pump adequate blood through the pulmonary circulation to the left side of the heart (decreased LV preload), resulting in reduced cardiac output and hypotension. The failing RV becomes reliant on hydrostatic pressure to force blood through the pulmonary circulation and is highly sensitive to a reduction in preload; nitrates, diuretics, and opioids are best avoided because they reduce RV preload and can profoundly worsen hypotension. Hypotension in the setting of RVMI is best initially treated with intravenous normal saline to further increase RV preload and provide additional hydrostatic pressure to assist blood flow through the pulmonary circulation. In contrast, LV contractile dysfunction resulting from LVMI, which is often recognized by pulmonary edema (absent in this patient), worsens with increased preload, and intravenous fluids should be avoided. Otherwise, patients with RVMI should undergo standard management of an acute STEMI with dual antiplatelet therapy, statins, anticoagulation, and urgent revascularization (eg, percutaneous intervention). management of an acute STEMI (Choice A) CT angiography of the chest is indicated in patients with suspected pulmonary embolism. However, ST-segment elevation in ECG leads II, III, and aVF is diagnostic of STEMI, for which CT angiography does not play a role. (Choice B) Immediate pericardiocentesis treats cardiac tamponade, which can present similarly to RVMI (eg, hypotension, JVD, clear lungs). However, localized ST-segment elevation is not expected with cardiac tamponade. (Choice C) Dopamine provides positive inotropy and is sometimes needed for RVMI patients with persistent hypotension despite adequate fluid resuscitation. (Choice E) Transient sinus bradycardia or atrioventricular block can occur during acute inferior wall MI and is managed with a temporary pacemaker. However, a temporary pacemaker is not indicated in this patient with normal heart rate and no evidence of atrioventricular block. Educational objective: Patients with right ventricular (RV) myocardial infarction can experience profound hypotension due to inadequate RV preload. These patients should be managed initially with intravenous saline bolus to increase RV preload and improve blood delivery to the left side of the heart. References: Right ventricular myocardial infarction: from pathophysiology to prognosis. (http://www.ncbi.nlm.nih.gov/pubmed/24294033)

A 64-Year-Old Man Comes to the Emergency Department Due to Intermittent