Junctional tachycardia (JT), or junctional ectopic tachycardia (JET), is a rapid, narrow complex tachycardia (usually 120-220 bpm) arising from a discrete focus within the atrioventricular (AV) node or His bundle. It may be regular or irregular.

The mechanism of action for JT usually involves increased automaticity in the AV node.

JT is typically seen in children and young adults. It is also seen in infants postoperatively after repair of congenital heart disease. It is usually highly symptomatic. It may result in heart failure in cases where tachycardia is incessant.

In adults, JT is less common, although it is sometimes seen in the setting of digoxin toxicity, myocardial infarction (MI), myocarditis, or cardiac surgery. It is usually benign in adults.