[Permanent junctional reciprocating tachycardia (Coumel type): an unusual location of a retrograde accessory pathway]

Permanent junctional reentrant tachycardia (PJRT) is an uncommon form of tachycardia that is usually due to an atrioventricular reentry via a right posteroseptal accessory pathway with decremental properties. We describe a case of PJRT that showed evidence of two accessory pathways located both left and right. A 63-year-old woman was referred to our institution for radiofrequency (RF) ablation of a permanent form of regular narrow QRS tachycardia (T) (cycle length 520 ms) with long RP interval (380 ms); P wave was negative in inferior leads, negative in D1 and flat in aVL. During sinus rhythm, AH and HV intervals were 110 ms and 50 ms respectively. The atrioventricular anterograde conduction curve was continuous. A decremental retrograde conduction via a left posterior pathway until ventricular effective refractory period (210 ms) was evident. Tachycardia inducible with both atrial and ventricular programmed stimulation was almost incessant. During tachycardia, a premature ventricular depolarization delivered when His bundle was refractory was able to advance the next atriogram, and tachycardia could be interrupted by a ventricular depolarization without atrial capture. During right atrial mapping, an earliest atrial activation was found in the mid-septal position just above the coronary sinus ostium and RF application caused a transient interruption of T (3 minutes). Tachycardia resumed with basal characteristics, but no evidence of earlier right atrial activation was found during atrial mapping. Successful RF ablation was performed via retrograde aortic catheterization in the left posterior region. This case showed evidence of a left posterior pathway causing PJRT. However, the transient successful ablation in the right mid-septal region and the lack of evidence of right early atrial activation after RF application could account for the presence of an additional right accessory pathway or a strand of the same broad left pathway.