<prompt> A 64-year-old man presents with increased shortness of breath. He has a past history of chronic obstructive pulmonary disease COPD and recently developed increased cough and sputum production but no fever or chills. He appears in mild respiratory distress, respirations are 26min, pulse 120 beatsmin, blood pressure 14584 mm Hg, and oxygen saturation 90. He has bilateral expiratory wheezes. His ECG reveals multifocal atrial tachycardia MAT discrete P waves with at least three different morphologies.For the above patient with an arrhythmia, select the most appropriate treatment.digitalisverapamildiltiazembeta-blockers  <response>: MAT usually occurs in the setting of advanced lung disease. Treatment involves withdrawing theophylline and improving lung function. There may be some role for treatment with verapamil. 