Intermittent fasciculoventricular pathway: ECG and electrophysiologic findings, clinical implications.

Although fasciculoventricular (FV) pathways never participate into tachycardia circuits, they give rise to ventricular pre-excitation of variable magnitude which can be source of ECG misinterpretation when associated to other supraventricular rhythm disorders. We report an intermittent FV pathway coincidentally unmasked during an electrophysiologic study performed for a symptomatic supraventricular tachycardia (atrial tachycardia). The clinical context, ECG and EP findings, and therapeutic options are described.

Long-term safety and efficacy of slow pathway ablation in patients with atrioventricular nodal re-entrant tachycardia and pre-existing prolonged PR interval.

The association of atrioventricular nodal re-entrant tachycardia (AVNRT) and pre-existing prolonged PR interval is unusual. Radiofrequency (RF) ablation in such patients may be associated with an increased risk of immediate and delayed AV block. The aim of our study is to assess the long-term efficacy and safety of slow pathway ablation in this population.