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 hypeensive patient with a complaint of palpitations and pre-syncope. On examination, his hea rate is 72 BPM and BP was 150/100. ECG performed shows? 
Select and explain. 
A. Atrial flutter, B. Atrial fibrillation, C. Multifocal atrial tachycardia, D. PSVT
A: Atrial flutter
Answer: A: Atrial flutter 
Explanation: ECG in lead II and other inferior leads shows the presence of flutter waves( Saw tooth pattern). 3-4 flutter waves before every narrow QRS complex. Since the ventricular rate is 75 bpm (RR interval), atrial rate shall be obtained by multiplying the ventricular rate by 4 which is 300 bpm The presence of risk factor of hypeension also give clue to diagnosis of atrial flutter.