**Abstract**

Supraventricular tachycardia (SVT) is an irregular heart rhythm in which the focus of impulse lies above the bundle of His, i.e., the sinus node, the atria, and the atrioventricular node (AVN). There are two types of SVT: Narrow QRS complex tachycardia and wide QRS complex tachycardia. Narrow QRS complexe tachycardias can further be divided as regular or irregular based on R–R intervals. There is further classification that can be made in regular rhythms in terms of RP interval. The most common tachycardias that are characterized by a long RP interval include sinus tachycardia, atrial tachycardia, and atrioventricular reentrant tachycardia. Short RP interval tachycardias mainly Atrioventricular nodal reentrant tachycardia (AVNRT), junctional tachycardia (JT) and permanent junctional reciprocating tachycardia (PJRT). On the other hand, irregular SVTs usually include atrial fibrillation, atrial flutter, and multifocal atrial tachycardia.

**Keywords:** Supraventricular tachycardia, Narrow QRS complex tachycardia, Wide QRS complex tachycardia, Atrioventricular reentrant tachycardia, Junctional rhythm, Permanent junctional reciprocating tachycardia, Atrial fibrillation
