A 62-year-old woman comes to the emergency department with a 2-week history of palpitations and mild shortness of breath. The patient has a history of hypertension and type 2 diabetes mellitus. She is a lifetime nonsmoker and has no family history of heart disease. Blood pressure is 144/70 mm Hg and pulse is 145/min and irregular. Oxygen saturation is 95% on room air. Lung examination reveals minimal rales at both bases. There are no heart murmurs.
ECG shows atrial fibrillation with rapid ventricular response. Transthoracic echocardiogram shows mild left atrial dilation and a diffusely hypokinetic left ventricle with an ejection fraction of 40%. Chemistry panel, serial troponin I, and TSH levels are normal.
The patient is treated with metoprolol and anticoagulation. On the third day of hospitalization, despite increasing doses of metoprolol, she still has palpitations. Blood pressure is 128/67 mm Hg, and pulse is 122/min and irregular.
Which of the following is the best next step in management of this patient?

Question

A 62-year-old woman comes to the emergency department with a 2-week history of palpitations and mild shortness of breath.  The patient has a history of hypertension and type 2 diabetes mellitus.  She is a lifetime nonsmoker and has no family history of heart disease.  Blood pressure is 144/70 mm Hg and pulse is 145/min and irregular.  Oxygen saturation is 95% on room air.  Lung examination reveals minimal rales at both bases.  There are no heart murmurs.
ECG shows atrial fibrillation with rapid ventricular response.  Transthoracic echocardiogram shows mild left atrial dilation and a diffusely hypokinetic left ventricle with an ejection fraction of 40%.  Chemistry panel, serial troponin I, and TSH levels are normal.
The patient is treated with metoprolol and anticoagulation.  On the third day of hospitalization, despite increasing doses of metoprolol, she still has palpitations.  Blood pressure is 128/67 mm Hg, and pulse is 122/min and irregular.
Which of the following is the best next step in management of this patient?

Quizplus · Accepted Answer

This patient has atrial fibrillation (AF) with rapid ventricular response and has developed decompensated heart failure likely due to uncontrolled ventricular rates and tachycardia-induced cardiomyopathy. She has failed initial attempts at rate control with atrioventricular nodal-blocking agents. At this point, the most appropriate management is attempted cardioversion to normal sinus rhythm as soon as possible; however, patients with AF for >48 hours can develop left atrial appendage thrombus and should have a transesophageal echocardiogram (TEE) prior to electrical or pharmacologic cardioversion. If atrial thrombus is definitively ruled out, the patient can proceed with electrical cardioversion right away and continue anticoagulation for 4 weeks afterward (to minimize the risk of systemic thromboembolism due to stunning of the atria with cardioversion). If atrial thrombus is not ruled out by TEE, the patient should be optimized on medical therapy and receive ≥3 weeks of anticoagulation prior to cardioversion. (Choices A and C) Myocardial ischemia is an uncommon precipitant of AF. Therefore, both myocardial perfusion imaging and cardiac catheterization, in the absence of more specific symptoms suggesting coronary artery disease, are not indicated in the acute setting. (Choices B and D) For pharmacologic cardioversion of AF, flecainide, a class IC antiarrhythmic drug, is sometimes effective, and sotalol, a class III antiarrhythmic drug, is less often effective. This patient has had AF for at least 2 weeks, and cardioversion without prior anticoagulation or TEE guidance carries an unacceptable risk of systemic thromboembolism. Moreover, flecainide is not recommended in patients with structural heart disease or left ventricular systolic dysfunction. Educational objective: Patients with atrial fibrillation for >48 hours who require nonemergent cardioversion should undergo transesophageal echocardiogram to assess for left atrial appendage thrombus. Patients in whom thrombus is ruled out can immediately proceed with cardioversion accompanied by periprocedural anticoagulation; otherwise, patients should receive ≥3 weeks of anticoagulation prior to cardioversion. __________ References: Role of transesophageal echocardiography-guided cardioversion of patients with atrial fibrillation. (http://www.ncbi.nlm.nih.gov/pubmed/11693739) Management of patients with atrial fibrillation (compilation of 2006 ACCF/AHA/ESC and 2011 ACCF/AHA/HRS recommendations): a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/23545139)

A 62-Year-Old Woman Comes to the Emergency Department with a 2-Week