<prompt> An 8 month old female child presented to emergency with a hea rate of 220minute and features of cogestive hea failure. Her hea rate comes down to normal after administering intravenous adenosine. What is the most likely diagnosis ?Atrial fibrillationAtrial flutterParoxysmal supraventricular tachycardiaVentricular tachycardia  <response>: Most common indication of adenosine is paroxysmal supra ventricular tachycardia Ref : Harrison principals and practice of internal medicine, 19th edition, p.no:1479 