ABSTRACT
STUDY OBJECTIVE: The objective of the study is to evaluate the difference in ventricular rate control using an intravenous (IV) metoprolol regimen commonly used in clinical practice in patients receiving chronic ß-blocker therapy compared to patients considered ß-blocker naive admitted to the emergency department (ED) for atrial fibrillation (AF) with rapid ventricular rate. METHODS: A single-center retrospective cohort study of adult ED patients who were admitted with a rapid ventricular rate of 120 beats per minute (bpm) or greater and treated with IV metoprolol was performed. Rate control was defined as either a decrease in ventricular rate to less than 100 bpm or a 20% decrease in heart rate to less than 120 bpm after metoprolol administration. Patient demographics, differences in length of stay, and adverse events were recorded. RESULTS: A total of 398 patients were included in the study, with 79.4% (n=316) receiving chronic ß-blocker therapy. Patients considered to be ß-blocker naive were more likely to achieve successful rate control with IV metoprolol compared to patients on chronic ß-blocker therapy (56.1% vs 42.4%; P=.03). ß-Blocker-naive status was associated with a shorter length of stay in comparison to patients receiving chronic ß-blocker therapy (1.79 vs 2.64 days; P<.01). CONCLUSION: Intravenous metoprolol for the treatment of atrial fibrillation with rapid ventricular rate was associated with a higher treatment response in patients considered ß-blocker naive compared to patients receiving chronic ß-blocker therapy.
