Ablation of typical atrial flutter guided by the paced PR interval on the surface electrocardiogram: a proof of concept study.

We aimed to assess the novel concept of using the paced PR interval (PRI) on the surface electrocardiogram (ECG) to prove trans-isthmus block after cavotricuspid isthmus (CTI) ablation for typical atrial flutter (AFl). Consecutive patients with AFl underwent linear radiofrequency ablation of the inferior CTI (6 o'clock). After AFl termination and/or presumed completion of the CTI line, CTI block was proven by atrial pacing by the ablation catheter medial (5 o'clock) and lateral to the line (7 and 9 o'clock). Corresponding PRIs were measured on the surface ECG. CTI block was assumed, if a sudden increase in the PRI was observed by moving the pacing site from 5 to 7 o'clock, and if the latter was longer than at 9 o'clock. Afterwards, bidirectional CTI block was confirmed by differential pacing. Thirty-one patients (mean age 67 ± 16 years, 81% male) underwent CTI ablation, and 18/31 (58%) were in AFl at the time of ablation (cycle length 249 ± 31 ms). Successful CTI block as defined by the PRI method was achieved in 31/31 (100%), and the mean PRIs during pacing at 5, 7, and 9 o'clock were 203 ± 56 ms, 329 ± 70 ms, and 296 ± 66 ms, respectively. Cavotricuspid isthmus block was confirmed in all patients (100%) by coronary sinus pacing with a reversal of the local activation sequence lateral to the isthmus line. The method of PRI analysis on the surface ECG to guide CTI ablation is easy to apply and highly accurate in confirming CTI block. This simple technique enables the novel concept of CTI ablation and proof of block with a single catheter.

Madaffari A ，Krisai P ，Spies F ，Knecht S ，Schaer B ，Kojic D ，Kühne M ，Sticherling C ，Osswald S ... -  《-》

Right ventricular pacing to assess transisthmus conduction in patients undergoing isthmus-dependent atrial flutter ablation: a new useful technique?

Vijayaraman P ，Kok LC ，Wood MA ，Ellenbogen KA ... -  《-》

A new and simple method for distinguishing complete from incomplete block through the cavotricuspid isthmus.

Laurent G ，Bourcier A ，Bertaux G ，Fromentin S ，Fraison M ，Gonzalez S ，Saint Pierre F ，Wolf JE ... -  《-》

Assessment of clockwise cavotricuspid isthmus block based on conduction times during transient entrainment: a prospective study.

Castellanos E ，Almendral J ，Puchol A ，Arias MA ，Cuena R ，Valverde I ，Pachón M ，Padial LR ... -  《-》

Reentry mechanisms and ablation of ECG-typical atrial flutters involving the cavo-tricuspid isthmus and the proximal coronary sinus.

Reentry circuits of a rare typical atrial flutter (AFL) involving the cavo-tricuspid isthmus (CTI) and proximal coronary sinus (CS) are described based on electrophysiological data and effects of radiofrequency (RF). Twelve patients with ECG-typical AFL in whom entrainment demonstrated that CTI and proximal CS were both part of the circuit were included. Initial RF target was CTI in 8 patients and proximal CS in 4. Success was defined as AFL termination/noninducibility. After CTI ablation, AFL cycle length (CL) increased in all: AFL persisted in 3, while in the other 5 AFL was interrupted but subsequently induced with the same morphology; before induction CTI bi-directional block was validated; success was obtained at the CS, targeting fragmented atrial potentials (APs). In those with first ablation at CS, AFL was interrupted in 3 with no AFL inducibility; in 1 AFL persisted with CL prolongation and was terminated at CTI. Two reentry patterns were identified: in 5 patients the inter-atrial septum as well as the mid-distal CS were outside of the circuit, while the CTI, proximal CS and Bachmann's bundle zone were inside, suggesting a left atrial component; in 1 patient electrophysiological mapping suggested an intra-CS circuit component. RF was successful in all without recurrence. Electrophysiological mapping and RF effects suggest a continuum between the CTI and proximal CS in rare cases with ECG-typical AFL. RF inside the proximal CS, targeting fragmented APs, should be considered in any patient in whom CTI ablation failed to interrupt a typical AFL.

De Sisti A ，Tonet J ，Márquez MF ，Amara W ，Broustet H ，Touil F ，Hidden-Lucet F ... -  《-》