Elimination of the Concealed Conduction via Left Lateral Accessory Pathway due to Insufficient Ablation May Led to Incessant AVRT and Development of Arrhytmogenic Cardiomyopathy

Case-report: 36-y.o. man had 4-years history of atrioventricular re-entry tachycardia (AVRT) with concealed left-lateral accessory pathway (AP), 3-5 episodes per year, 30-40 minutes duration without hemodynamic compromise. Two years ago patient underwent ablation of concealed left lateral AP with followed recurrence of narrow QRS tachycardia in 10 days. After that clinical time course of tachycardia became malignant: 150 beats per minute, incessant (lasting up to 18 h/day), resistant to AAD, and led to development of tachycardia-induced cardiomyopathy (EF was 16%, and 2 episodes of pulmonary oedema). During redo EPS we verified AVRT with conduction via decremental retrograde left lateral AP which corresponded to the criteria of permanent junctional reciprocating tachycardia (PJRT). We used transeptal approach and 3D-reconstruction of left atrium for mapping and ablation of AP. RF-application at the site of AP mapping immediately terminated the AVRT (3 seconds) without followed retrograde VA-conduction. After 18 months of follow up patient had signs of left ventricle reverse remodeling and had not heart failure symptoms and recurrence of arrhythmia.

Conclusion: Worsening of arrhythmia time course may be result of elimination of concealed antegrade slowly conduction via AP. Incessant AVRT was effectively treated by redo ablation of AP with followed abolition of heart failure symptoms.