A 60-year-old man comes to the hospital with chest pain. He has had intermittent, squeezing substernal pain over the last 3 days that is now sustained. The patient has no associated palpitations, lightheadedness, or shortness of breath. Medical history is notable for moderate chronic obstructive pulmonary disease with a recent admission for an exacerbation. Blood pressure is 145/90 mm Hg and pulse is 93/min. Oxygen saturation by pulse oximetry is 98% on room air. Physical examination shows no heart murmurs, and lungs are clear to auscultation. ECG shows sinus rhythm with 2-mm anterior ST segment elevation. Cardiac troponin I levels are elevated. Which of the following is the most appropriate treatment for this patient?

Question

A 60-year-old man comes to the hospital with chest pain.  He has had intermittent, squeezing substernal pain over the last 3 days that is now sustained.  The patient has no associated palpitations, lightheadedness, or shortness of breath.  Medical history is notable for moderate chronic obstructive pulmonary disease with a recent admission for an exacerbation.  Blood pressure is 145/90 mm Hg and pulse is 93/min.  Oxygen saturation by pulse oximetry is 98% on room air.  Physical examination shows no heart murmurs, and lungs are clear to auscultation.  ECG shows sinus rhythm with 2-mm anterior ST segment elevation.  Cardiac troponin I levels are elevated.  Which of the following is the most appropriate treatment for this patient?

Quizplus · Accepted Answer

11ec160b_3b95_b199_9249_3b7de51c97e9_MD0001_00 This patient's clinical presentation-chest discomfort, ST elevation on ECG, elevated troponin I level-is consistent with acute myocardial infarction (AMI). Beta blockers are used in AMI to reduce myocardial oxygen demand by lowering heart rate, cardiac contractility, and afterload. They have been shown to reduce short-term morbidity (eg, recurrent symptoms or reinfarction), minimize infarct size, and improve long-term survival. Contraindications to beta blockers include bradycardia or heart block, hypotension, and overt heart failure (eg, pulmonary edema). Also, non-cardioselective beta blockers (eg, propranolol, nadolol) can trigger bronchospasm in patients with underlying obstructive lung disease (asthma, chronic obstructive pulmonary disease [COPD]) due to beta-2 receptor blockade and should be avoided (Choices C and D). Cardioselective beta blockers with predominant action on beta-1 receptors (eg, metoprolol, atenolol, bisoprolol, nebivolol) are safe in patients with stable obstructive lung disease and are the beta blocker of choice in these patients. Combined beta and alpha receptor blockers (eg, carvedilol, labetalol) are also well tolerated and have been used safely in patients with COPD. (Choice A) Ibutilide is a class III antiarrhythmic drug (potassium channel blocker) used for acute termination of atrial flutter or atrial fibrillation. Like other class III antiarrhythmics, ibutilide causes prolonged QT interval that can precipitate a deadly arrhythmia (torsade de pointes). (Choice E) Sotalol is a class III antiarrhythmic drug with beta blocker properties and is primarily used for the treatment of atrial and ventricular arrhythmias. It would not be indicated in a patient with a recent myocardial infarction who is in sinus rhythm. Educational objective: Beta blockers are used in acute myocardial infarction to reduce morbidity and mortality by decreasing cardiac output and myocardial oxygen demand. Non-cardioselective beta blockers (eg, propranolol, nadolol) can trigger bronchospasm in patients with underlying asthma or chronic obstructive pulmonary disease. Cardioselective beta blockers (eg, metoprolol) predominantly affect beta-1 receptors and are preferred in such patients. __________ References: Use of cardioselective ß-blockers in patients with chronic obstructive pulmonary disease: a meta-analysis of randomized, placebo-controlled, blinded trials. (http://www.ncbi.nlm.nih.gov/pubmed/23321161)

A 60-Year-Old Man Comes to the Hospital with Chest Pain