Ablation of AVNRT in a Setting of Slow Pathway-Dominant Conduction.

BACKGROUND

We report a case of paroxysmal supraventricular tachycardia with slow pathway-dominant conduction and prolonged PR interval in sinus rhythm.

CASE SUMMARY: A 33-year-old man presented with persistent palpitations and chest tightness, with narrow QRS tachycardia with a prolonged PR interval on electrocardiogram. After the administration of isoproterenol, the PR interval normalized. During the electrophysiology study, atrioventricular node conduction jumping, echoes, and dual ventricular responses were observed. After ablation, the fast pathway function of the atrioventricular node was restored, and electrocardiography revealed a normal PR interval.

DISCUSSION: This case demonstrates that slow pathway-dominant atrioventricular nodal re-entrant tachycardia can be successfully treated by slow pathway ablation, while ensuring normal fast pathway function is key to avoiding atrioventricular block.

TAKE-HOME MESSAGE: Slow pathway ablation effectively treats this arrhythmia, and the preservation of fast pathway function is crucial to avoid atrioventricular block.