<prompt> A 34-year-old male with history of Palpations came to emergency with a pulse rate 156min and with a BP-7040 mm Hg.Emergency crew has tried vagal maneuver and adenosine to which the rhythm is refractory. What is the next step:Repeat adenosineAmiodaroneDC shockAdrenaline  <response>: Ans. C DC shockRef: Harrisons Principle of Internal Medicine 20th Ed; Page No-1742 ECG Findings: Typical AVNRT SVT. The patient is hemodynamically unstable so Shock is needed.Atrioventricular Nodal Reentrant Tachycardia AVNRTIt is a type of supraventricular tachycardia i.e. it originatesabove the level of the Bundle of His and is the commonestcause of palpitations in patients with hearts exhibiting nostructurally abnormality.Slow-Fast AVNRT Common AVNRT Accounts for 80-90 of AVNRT Associated with Slow AV nodal pathway for anterogradeconduction and Fast AV nodal pathway for retrogradeconduction. The retrograde P wave is obscured in the correspondingQRS or occurs at the end of the QRS complex as pseudo ror S waves ECG: P waves are often hidden - being embedded in the QRScomplexes. Pseudo rwave may be seen in VI Pseudo S waves may be seen in leads II, III or aVF. In most cases this results in a typical5 SVT appearance withabsent P waves and tachycardia Treatment: If unstable, cardiovert. If stable, try vagal maneuvers, IV adenosine, metropolol, or verapamil 