Prescribing Safety Assessment (PSA) Practice Exam

What is the first choice of action in managing atrial fibrillation if the onset is greater than 48 hours?

1. Immediate cardioversion

2. Beta Blocker monotherapy

3. Anticoagulation therapy

4. Electrical cardioversion only

The correct answer is: Beta Blocker monotherapy

In cases of atrial fibrillation where the onset is greater than 48 hours, the priority is to prevent thromboembolic complications, such as stroke, which can occur due to stagnant blood flow in the atria. The correct initial management step is the initiation of anticoagulation therapy. This is crucial as it helps reduce the risk of thrombus formation in the left atrial appendage, a common site for clot development in patients with atrial fibrillation. Anticoagulation is often recommended for at least three weeks prior to any planned cardioversion (if electrical conversion to sinus rhythm is deemed necessary later on). This approach ensures that any existing clots can be addressed before attempting to restore normal rhythm. While immediate cardioversion may be necessary in specific emergency cases, in the absence of urgent clinical need, starting with anticoagulation is the safer approach when the duration of atrial fibrillation exceeds 48 hours. Beta blockers may help with rate control, but they do not address the immediate concern of potential clot formation and are not the first line of action in this scenario. Therefore, initiating anticoagulation therapy aligns with standard guidelines and practice protocols in the management of atrial fibrillation.