A 62-year-old female with a medical history of COPD and angina presents with acute onset of dizziness, chest pain and shortness of breath. Her HR is 152 and BP is 86/56. Her EKG shows irregular narrow complex rhythm without P waves. Treatment?

A. Metoprolol IV, then consult
B. Digoxin IV, then consult
C. Synchronized cardioversion, then consult
D. Pacemaker, then consult