The most common presentation of cardiac patients in the emergency room is myocardial   infarction, followed by arrhythmia. The most common in arrhythmia is atrioventricular   arrhythmia, AVNRT (atrioventricular nodal reentrant tachycardia) being the most common.  The treatment for undifferentiated narrow complex QRS, (not for all narrow complex   tacchycardia) based on the current ACLS guidelines is vagal maneuvers and adenosine. In an   unstable narrow complex, synchronized cardioversion is the preferred method for treatment.  In this case report, we discuss a patient who, along with his attendants, refused for shock therapy for unstable supraventricular tachycardia, its management and further course.