This document discusses atrioventricular nodal reentrant tachycardia (AVNRT), which accounts for about 2/3 of paroxysmal supraventricular tachycardia cases. It involves a dual pathway in the AV node that can lead to a reentrant circuit triggered by a premature atrial complex. Management in the acute setting includes vagal maneuvers, adenosine, calcium channel blockers, or cardioversion. Long term management depends on severity and may involve medications like digoxin, beta blockers, calcium channel blockers, or catheter ablation, which has a 95% success rate but 1% risk of AV block.