This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: ECG and Arrhythmia 2, Subject name: Medicine
A 70 year old COPD patients presents with palpitations. ECG rhythm strip shows? 
Select and explain. 
A. Inappropriate sinus Tachycardia, B. Junctional Tachycardia, C. Atrial fibrillation, D. Multifocal Atrial Tachycardia
D: Multifocal Atrial Tachycardia
Answer: D: Multifocal Atrial Tachycardia 
Explanation: ECG strip shows a hea rate of approximately 120/min with normal sinus rhythm. However a very peculiar finding is present here with variable P wave morphology. MC arrhythmia in COPD patients is M.A.T (Multifocal atrial tachycardia). It originates due to multiple ectopic foci in atria. Choice A has an exaggerated response to emotional stimuli like fear. Choice B has Retrograde P waves with narrow complex QRS. (Blue arrows) Choice C has absent P waves with irregular RR interval.