<prompt> A 40 year old man was admitted to the hospital emergency with sudden onset of the symptoms and signs of severe left ventricular failure. Calculate the atrial rate of the patient.100min150min200min300min  <response>: Ventricular rate : 150010 150 ECG shows HR of 150min with normal axis. Saw tooth waves are noted with 2:1 AV block. Ventricular rate is 150min therefore the atrial rate would be 300min. 