What is the appropriate treatment for atrial fibrillation associated with thyrotoxicosis?

In the context of treating atrial fibrillation associated with thyrotoxicosis, the use of esmolol IV infusion is particularly appropriate due to its rapid onset and short duration of action. Thyrotoxicosis often leads to increased sympathetic tone, which can exacerbate atrial fibrillation. Esmolol, a selective beta-1 adrenergic antagonist, is effectively used in this situation because it quickly reduces heart rate and myocardial oxygen demand, which is vital in managing the fast heart rates commonly seen in atrial fibrillation caused by hyperthyroidism.

The intravenous route allows for more precise control over the patient's heart rate and can be titrated rapidly in an acute setting, making it ideal for emergency situations. Additionally, its short half-life means that if the patient's condition changes or if side effects are observed, the drug can be quickly cleared from the system, minimizing potential complications.

In contrast, while other treatments like atenolol or metoprolol could be considered, they typically have longer onset times and durations, which might not be optimal in acute situations. Digoxin, although used in atrial fibrillation for rate control, generally has a slower onset significantly compared to esmolol and is not typically the first-line treatment in cases