Supraventricular tachycardia (SVT) is a type of tachyarrhythmia with a narrow QRS complex and regular rhythm (heart rate >100 bpm). These patients are often symptomatic and present to the emergency department (ED) in acute attacks called paroxysmal SVT (PSVT). Most SVTs are regular rhythms. It starts suddenly with the reentry mechanism in the majority of patients. 60% of the patients have reentry with Atrioventricular (AV) node, and 20% have reentry via bypass pathways. Coronary artery disease, anginal chest pain and dyspnea occur in patients due to tachycardia. Heart failure and pulmonary edema may occur with left ventricular dysfunction. Vagal maneuvers and adenosine appear to be the treatments of choice for termination of stable SVT.