Dual Atrioventricular Nodal Non-Reentrant Tachycardia

Dual atrioventricular nodal non-reentrant tachycardia (DAVNNT) is a rare arrhythmia often misdiagnosed as atrial fibrillation, leading to inappropriate management. We present a case of DAVNNT successfully treated with slow pathway ablation.

A 77-year-old woman with palpitations and syncope was initially thought to have sick sinus syndrome, supraventricular ectopic beats, and atrial fibrillation, resulting in pacemaker implantation and anticoagulation. Following device implantation, persistent tachycardia was observed. Electrocardiographic and intracardiac electrogram analysis suggested DAVNNT, which was confirmed by electrophysiology study. Slow pathway ablation resolved the arrhythmia and symptoms, allowing discontinuation of anticoagulation and beta-blocker therapy.

Careful analysis of electrocardiographic and electrogram data was crucial in identifying DAVNNT, a rare but treatable arrhythmia. This case highlights the importance of considering alternative diagnoses in patients presenting with bradycardia, syncope, and supraventricular arrhythmias.