A 76-year-old man with coronary artery disease comes to the office for follow-up 6 months after an uncomplicated coronary artery bypass surgery. The exertional chest pain that was bothering the patient before the surgery has completely resolved. He reports no palpitations, shortness of breath, light-headedness, or syncope. The patient has a history of hypertension, diet-controlled type 2 diabetes mellitus, and gout. Medications include low-dose aspirin, metoprolol, and rosuvastatin. He has a 30-pack-year smoking history but quit 5 years ago. The patient does not use alcohol or illicit drugs. Physical examination shows an irregular pulse. The chest surgical incision is well healed. There are no heart murmurs, and the lungs are clear on auscultation. There is no peripheral edema. ECG obtained in the office is shown in the exhibit.

Which of the following is the best management for this patient?

Question

A 76-year-old man with coronary artery disease comes to the office for follow-up 6 months after an uncomplicated coronary artery bypass surgery. The exertional chest pain that was bothering the patient before the surgery has completely resolved. He reports no palpitations, shortness of breath, light-headedness, or syncope. The patient has a history of hypertension, diet-controlled type 2 diabetes mellitus, and gout. Medications include low-dose aspirin, metoprolol, and rosuvastatin. He has a 30-pack-year smoking history but quit 5 years ago. The patient does not use alcohol or illicit drugs. Physical examination shows an irregular pulse. The chest surgical incision is well healed. There are no heart murmurs, and the lungs are clear on auscultation. There is no peripheral edema. ECG obtained in the office is shown in the exhibit.

Which of the following is the best management for this patient?

Quizplus · Accepted Answer

This patient's ECG demonstrates saw-toothed flutter waves consistent with atrial flutter. The atrial rate is typically approximately 300/min, and the ventricular response can be constant or variable. This patient has a variable ventricular response rate that creates an irregular rhythm, whereas a constant ventricular response rate (eg, a constant 3:1 ventricular response at a rate of 100/min) can create a regular-appearing rhythm. flutter waves Atrial flutter usually results from a large reentrant circuit involving the cavotricuspid isthmus of the right atrium. Risk factors are similar to those for atrial fibrillation and include coronary artery disease, hypertension, and heart failure. The arrhythmia is also frequently seen following cardiac surgery. Atrial flutter carries a similar risk of arterial thromboembolism to atrial fibrillation; therefore, this patient with multiple CHA₂DS₂-VASc risk factors should be started on chronic anticoagulation (eg, rivaroxaban, apixaban) therapy. reentrant circuit CHA₂DS₂-VASc Although not needed in this patient (whose pulse is ~60-70/min), management also involves rate control, which can sometimes be difficult to accomplish with medications alone (eg, metoprolol, verapamil). Definitive management often requires radiofrequency ablation to disrupt the reentrant circuit, or electric cardioversion is also sometimes an option. These interventions increase the risk of a thromboembolic event and should be preceded by several weeks of anticoagulation therapy. (Choice A) Atrioventricular (AV) nodal slow pathway ablation is used to treat AV nodal reentrant tachycardia, a type of supraventricular tachycardia. ECG would show a regular rhythm with rapid rate and no P waves. ECG (Choice B) Exercise stress testing is used to evaluate for coronary artery disease in patients with suggestive symptoms (eg, chest pain on exertion), but it is not indicated in this patient. (Choice C) Flecainide is a class IC antiarrhythmic that is sometimes used to treat atrial fibrillation. Such rhythm-control agents are generally not used for atrial flutter because of poor efficacy and the risk of precipitating rapid ventricular response. (Choice E) Routine follow-up in 6 months is not appropriate because atrial flutter significantly increases the risk of embolic stroke in this patient with multiple CHA₂DS₂-VASc risk factors. Educational objective: Atrial flutter is recognized by saw-toothed flutter waves on ECG; the rhythm can be regular or irregular depending on the variability of the ventricular response rate. Atrial flutter carries a similar risk of arterial thromboembolization to atrial fibrillation and should be similarly managed with chronic anticoagulation. References: Atrial flutter and the risk of thromboembolism: a systemic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/15694889)

A 76-Year-Old Man with Coronary Artery Disease Comes to the Office