USMLE Step 3 - Question 49

An 82 year old male with a history of hypertension presents to his primary care physician for a routine visit. He has had some generalized fatigue but attributed it to aging. His temperature is 37.0, blood pressures 110/60, heart rate 70, and respirations 20. Physical examination reveals normal lung sounds, an irregularly irregular rhythm, and no lower extremity edema. Laboratory studies including thyroid tests and a complete blood count are normal. Below is his ECG. Which of the following is the most appropriate therapy at this time?

AfibIrregular

A. Calcium channel blocker

B. Beta-blocker

C. Digoxin

D. Coumadin

This patient has atrial fibrillation on his ECG which can present without any symptoms or with severe symptoms such as syncope. The ECG shows an irregularly irregular QRS complex with the absence of P waves. Controlling the heart rate with non-dihydropyridine calcium channel blockers (verapamil or diltiazem) is one goal of therapy, however out patient’s heart rate is already well controlled (as is common in the elderly). The second goal of therapy is to prevent thromboembolism resulting in stroke. This is accomplished using Coumadin. To determine if the stroke risk is high enough to warrant anticoagulation using Coumadin, a scoring system is in widespread use called the “CHADS 2 score” and also the "CHADS 2 Vasc score". C stands for congestive heart failure (1 point), H for hypertension (1 point), A for age > 75 (1 point) and D for diabetes (1 point). The 2 is for prior stroke or transient ischemic attack (2 points). Two or more points warrants anticoagulation which can be done with coumadin (warfarin), dabigatran, apixiban, or rivaroxiban. Aspirin daily can be used if there is 1 point or less. A rhythm control approach to our patient could be argued since he is symptomatic (fatigue), however the success at his age with undetermined chronicity of the  atrial fibrillation makes rate control and anticoagulation adequate. Remember that digoxin is technically only indicated for atrial fibrillation if it coexists with systolic congestive heart failure.