1
A 74-year-old man with severe COPD presents with worsening dyspnea. ECG shows an irregular narrow-complex tachycardia at 135/min with at least three different P-wave morphologies and variable PR intervals. What is the most likely diagnosis?
B
Multifocal atrial tachycardia
C
Atrial flutter with variable block
D
Sinus tachycardia with frequent PACs