Micro-reentry right atrial tachycardia originating from fossa ovalis: a case report of high-density mapping by PentaRay catheter

Abstract

Background Micro-reentry tachycardia usually emerges in scar tissues related to post-atrial fibrillation ablation and cardiomyopathy. It is difficult to identify the micro-reentry circuit accurately by conventional mapping method. Case summary A 74-year-old man presented with paroxysmal atrial tachycardia (AT) presenting as palpitations. He was evaluated by an electrophysiological examination using a high-density CARTO mapping system. The mapping results showed the AT with a cycle length of 184 ms was focused on his right atrial fossa ovalis (FO). In this small area, the high-density mapping demonstrated a significant micro-reentrant tachycardia. Radiofrequency ablation at the centre of the micro-reentrant circuit successfully terminated the AT. No recurrences were observed during a 12-month follow-up. Discussion This case demonstrated a micro-reentrant AT originates from the FO without cardiomyopathy or previous ablation with specific loops. This is an unusual location for AT though and can cause difficulty for operators if it terminates or is non-sustained. High-density mapping using a PentaRay catheter can effectively characterize micro-reentrant circuits and determine the real target for ablation therapy.

Maternal focal atrial tachycardia during pregnancy: A systematic review

“…High‐density mapping with multielectrode catheters may decrease procedure time and increase ablation success 56 . Although none of the patients in our review had microreentry, high‐density mapping has recently been reported to be useful in defining circuits and best ablation sites 57,58 …”

Focal atrial tachycardia originating from mirror position of fossa ovalis: A case report

“…[7]. Although there are two reported cases of FAT arising from FOv [8,9], the left septal origin of FAT focusing on FOv has no written literature. The present case firstly reported a FAT arising from the left atrial mirroring position of FOv.…”

“… 6 Some studies demonstrate that the actual interatrial structure of the IAS is the FOV with its rim. 7 Although there are 2 reported cases of FAT arising from the FOv, 8 , 9 the left septal origin of FAT focusing on the FOv has no written literature. The present case firstly reported a FAT arising from the LA mirroring position of the FOv.…”