patients with either new onset ( less than 48 hours , n = 31 ) or old onset ( greater than 48 hours , n = 14 ) of atrial fibrillation or flutter with rapid ventricular rate were stratified to receive esmolol ( n = 21 ) or verapamil ( n = 24 ) .
C0004238
atrial fibrillation
C0042523
verapamil