Comparison between the novel diamond temp and the classical 8-mm tip ablation catheters in the setting of typical atrial flutter

PURPOSE

Radiofrequency (RF) catheter ablation is widely accepted as a first-line therapy for cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). The novel DiamondTemp (DT) catheter with temperature feedback during RF ablation has been released recently on the market. The purpose of this study was to evaluate the impact of DiamondTemp (DT) technology on ablation efficiency during AFL.

METHODS

In this single-center study, 30 consecutive patients with typical AFL indicated to ablation of CTI were included. The first 15 patients underwent CTI ablation using 8-mm tip catheter, and the following 15 patients underwent temperature-controlled RF ablation using DT catheter. The endpoints were number and mean total duration of RF applications, mean temperature reached in the setting of CTI, procedural times, and fluoroscopy times.

RESULTS

There were no significant differences between the two groups concerning baseline characteristics. Mean duration of the each application (71.5 s ± 30.6 vs 12.4 s ± 13.2, p value < 0.001), mean total duration of RF applications (517,73 s ± 377,96 vs 112,8 s ± 43,58; p value < 0.001), procedural times (51.6 min ± 24.2 vs 38.6 ± 8.2; p = 0.03), and fluoroscopy times (16.2 min ± 10.2 vs 8 min ± 4.24; p = 0.005) were longer in the 8-mm ablation catheter group. Mean temperature measurements (51.9 °C ± 3.59 vs 56.7 °C ± 3.34, p value < 0.003) were as well lower in the 8-mm ablation catheter group.

CONCLUSIONS

Catheter ablation of CTI-dependent AFL by means of DT resulted in a significant reduction of total and single application RF delivery time, procedure, and fluoroscopy times.

The optimized clinical workflow for pulmonary vein isolation with the radiofrequency balloon

PURPOSE

Pulmonary vein isolation (PVI) with radiofrequency (RF) catheter ablation is an effective treatment option for patients with paroxysmal AF. However, traditional point by point RF ablation can be time consuming and technically challenging. To simplify the ablation procedure, without compromising procedure outcome, several "single shot" ablation systems have been developed. The multi-electrode RF Balloon catheter HELIOSTAR is a 28-mm compliant balloon compatible with the CARTO 3D electroanatomical mapping system; an optimized step-by-step workflow to perform PVI is described.

METHODS

Procedures are performed under general anesthesia with unique transseptal puncture. To evaluate the optimal electrode-tissue contact and best RF Balloon positioning, the following baseline indicators should be fulfilled: inflation index > 0.8, impedance range close to 100 Ohms with a variability of less than 20 Ohms across electrodes, temperature variability on all electrodes < 3 °C with a maximum temperature of 31 °C.

RESULTS

RF delivery along the posterior wall is programmed to 20 s or shorter in case of esophageal temperature rise (> 2 °C compared to baseline) and 60 s for all the other segments. Target parameters for PVI are 1) time to isolation less than 12 s; 2) impedance drop > 12 Ohms; 3) temperature rise > 6 °C.

CONCLUSIONS

Standardized workflow for RF Balloon is mandatory to achieve efficacy and safety with this new promising technology. In the absence of international guidelines, a single high-volume center procedural strategy is described for PVI.

High vagal tone predicts pulmonary vein reconnection after cryoballoon ablation for paroxysmal atrial fibrillation

BACKGROUND

Pulmonary vein (PV) isolation is an established treatment for paroxysmal drug-refractory atrial fibrillation (AF). High parasympathetic tone and reconnection of PVs have demonstrated to be possible culprits of AF recurrence after ablation. Our aim was to investigate the association between parasympathetic tone and reconnected PVs in patients with paroxysmal AF.

METHODS

Consecutive patients who underwent a redo catheter ablation procedure for atrial tachyarrhythmia recurrence by means of 3D electroanatomic mapping with documentation of presence or absence of PVs reconnection following an initial procedure of cryoballoon (CB) ablation for symptomatic drug-refractory paroxysmal AF were screened for the study.

RESULTS

A total of 92 patients were included, of whom 50 (54.35%) were males. Reconnected PVs were found in 64 (69%) patients. PVs reconnection could be predicted by DC (C-statistic = .770), by SDNNI (C-statistic = .714) and by absolute VLF power (C-statistic = .722), while right-sided PVs reconnection could be better predicted by DC (C-statistic = .848) and by SDNNI (C-statistic = .761). In multivariate binary logistic regression analysis, a DC value ≥6.45 ms and an absolute VLF power value ≥160 ms² were associated with three times and five times higher odds of PVs reconnection, respectively. On a vein-per-vein analysis, absolute VLF power ≥160 ms² was associated with three times higher odds, while reaching of -40°C within 60 s was associated with three times lower odds of PVs reconnection.

CONCLUSION

High parasympathetic tonus accurately predicts PVs reconnection. On a vein-per-vein analysis, parasympathetic markers along with biophysical parameters predicted PVs reconnection. On a case-by-case analysis, parasympathetic markers were the only predictors of PVs reconnection, thus being a robust PVs reconnection prediction tool.

Novel noncontact charge density map in the setting of post-atrial fibrillation atrial tachycardias: first experience with the Acutus SuperMap Algorithm

PURPOSE

The purpose of this study was to evaluate the safety and feasibility of the new high-resolution mapping algorithm SuperMap (Acutus Medical, CA, USA) in identifying and guiding ablation in the setting of regular atrial tachycardias following index atrial fibrillation (AF) ablation.

METHODS

Seven consecutive patients who underwent a radiofrequency catheter ablation guided by the novel noncontact charge density (CD) SuperMap for atrial tachycardia were prospectively enrolled in our study.

RESULTS

Arrhythmogenic substrate was identified in all seven patients. Mean number of EGM per map was 5859.7 ± 4348.5 points. Three patients (43%) exhibited focal tachycardia mechanisms in the left atrium, alternating from anteroseptal right superior pulmonary vein (RSPV), posterior in proximity of left inferior pulmonary vein (LIPV), and interarial septum in proximity of fossa ovalis, respectively. Four patients exhibited macroreentrant mechanism. In 3 of these patients, SuperMap detected mitral isthmus-dependent flutters with tachycardia cycle lengths of 240, 270 and 420 ms, respectively. In one patient, the mechanism was a macroreentrant tachycardia with the critical isthmus located between the crista terminalis and atriotomy. The mean ablation time (min) was 18.2 ± 12.5 and the mean procedural duration time was 56.4 ± 12.1 min. No minor or major complications occurred.

CONCLUSION

The novel high-resolution mapping algorithm SuperMap proved to be safe, fast, and feasible in identifying and guiding ablation in the setting of regular atrial tachycardias following index AF ablation.

P1401Electrophysiological findings during repeat procedures in patients exhibiting electrical isolation in all veins after an index cryoballoon procedure for paroxysmal atrial fibrillation

Introduction

The purpose of this study was to analyze and compare the electrophysiological findings in redo radiofrequency (RF)-ablation of AF in a series of patients with durable PV isolation (PVI) and with PV reconnection after index procedure with the second-generation cryoballon (CB).

Methods and results

A total of 132 patients (81 males, 60.7 ± 12.4 years) who underwent CB-A for paroxysmal AF (PAF) were enrolled. Indication for the redo procedure was symptomatic (PAF) in 83 (63%) and persistent AF (PeAF) or persistent regular atrial tachycardia (RAT) in 49 (37%). Seventy-five (57%) patients presented a PV reconnection (PV group), whereas 57 (43%) no PV reconnection (non-PV group). The non-PV group exhibited significantly more atrial flutters and non-PV foci than the PV group after induction protocol (67% vs. 36%, p = 0.003 and 51% vs. 24% p = 0.002, respectively) (Table 1). Twenty-two (29.3%) patients of the PV group and 20 (35%) patients of the non-PV group had AF/RAT recurrence after a mean follow-up of 12.5 ± 8 months. The survival analysis demonstrated no statistical significance in recurrence between the two groups (log rank p = 0.358). In the cox regression analysis only the AF/RAT recurrence in the blanking period could predict independently an AF/RAT relapse.

Conclusions

AF/RAT recurrence in patients after CB-A with durable PVI is significantly associated to atrial flutters and non-PV foci. No statistically different success rate regarding AF/RAT freedom was detected between PV and non-PV Group after redo RF-CA.

Table 1. Electrophysiological findings PV Groupn = 75 non-PV Groupn = 57 p-value PV trigger (n of patients) 75(100) 0(0) &lt;0.001 LSPV 29 (39) 0 (0) &lt;0.001 LIPV 15 (20) 0 (0) &lt;0.001 RSPV 27 (36) 0 (0) &lt;0.001 RIPV 33 (44) 0 (0) &lt;0.001 Atrial flutters (n of patients) 27 (36) 38 (67) 0.003 Roof-flutter 13 (17) 34 (60) 0.0001 Peri-mitral-flutter 9 (12) 20 (35) 0.003 Right flutter 13 (17) 5 (9) 0.2 Non-PV foci (n of patients) 18 (24) 29 (51) 0.002 Categorical variables are expressed as absolute and percentage (in brackets). LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; PV, pulmonary vein; RSPV, right superior pulmonary vein; RIPV, right inferior pulmonary vein.