Tip Cryoablation Research Articles

Efficacy and safety between radiofrequency ablation and types of cryoablation catheters for atrioventricular nodal reentrant tachycardia: A Network Meta-analysis and Systematic Review.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common supraventricular tachycardia referred for ablation. Periprocedural conduction system damage was a primary concern during AVNRT ablation. This study aimed to assess the incidence of permanent atrioventricular (AV) block and the success rate associated with different types of catheters in slow pathway ablation. A literature search was performed to identify studies that compared various techniques, including types of radiofrequency ablation (irrigated and nonirrigated) and different sizes of catheter tip cryoablation (4, 6, and 8-mm), in terms of their outcomes related to permanent atrioventricular block and success rate. To assess and rank the treatments for the different outcomes, a random-effects model of network meta-analysis, along with p-scores, was employed. A total of 27 studies with 5110 patients were included in the analysis. Overall success rates ranged from 89.78% to 100%. Point estimation showed 4-mm cryoablation exhibited an odds ratio of 0.649 (95%CI: 0.202-2.087) when compared to nonirrigated RFA. Similarly, 6-mm cryoablation had an odds ratio of 0.944 (95%CI: 0.307-2.905), 8-mm cryoablation had an odds ratio of 0.848 (95%CI: 0.089-8.107), and irrigated RFA had an odds ratio of 0.424 (95%CI: 0.058-3.121) compared to nonirrigated RFA. Our study found no significant difference in the incidence of permanent AV block between the types of catheters. The success rates were consistently high across all groups. These findings emphasize the potential of both RF ablation (irrigated and nonirrigated catheter) and cryoablation as viable options for the treatment of AVNRT, with similar safety and efficacy profile.

PC-578-02 JUNCTIONAL TACHYCARDIA

Junctional ectopic tachycardia (JET) is a rare tachyarrhythmia in adults. The precise site of origin within the AV junction is unknown. N/A N/A A 71-year-old male presented with dyspnea on exertion and recently diagnosed tachycardia in March 2021. He had a history of diabetes mellitus, obesity, hypertension, obstructive sleep apnea, and COVID-19 in 2020. A 14-day monitor demonstrated 43% supraventricular ectopy SVE burden and short runs of SVT. He presented for an electrophysiology (EP) study. He presented to the EP lab in sinus rhythm with frequent SVE. Multipolar catheters were placed in the His bundle region, right atrium, coronary sinus, and right ventricle. The SVE beats had the same QRS morphology, and an identical HV interval and His-right bundle activation sequence as in sinus rhythm and no retrograde conduction, consistent with premature junctional complexes (PJCs). Occasional short bursts of junctional tachycardia were noted. Isoproterenol was titrated to a maximum dose of 8 mcg/min. No other SVT was inducible with atrial overdrive pacing or programmed stimulation or with isoproterenol infusion. A 6 mm tip cryoablation catheter was advanced to the right atrium to the anatomical location of the slow pathway in the inferior triangle of Koch using an electroanatomic mapping system (EnSite NavX). Signals immediately prior to ablation (Figure 1) were notable for a pre-potential 26 ms prior to the His with PJCs. Cryoablation was performed at this site (Figure 2) with resolution of the PJCs at the onset of the freeze. After thawing, a second freeze was administered. No further PJCs were noted at baseline or with isoproterenol infusion. JET could originate from anywhere within the AV node or proximal His bundle. The application of cryoablation at a typical AV nodal slow pathway location with a preceding pre- potential and immediate obliteration of PJCs suggests that the origin in this case was from this region rather than a true His bundle extrasystole. Identification of pre-potentials to the junctional ectopy can guide safe ablation of this dysrhythmia.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Is signal resolution of linear cryocatheters appropriate to map superoparaseptal accessory pathways? A comparison with Orion high-resolution mapping.

Larger tip cryoablation catheters can dampen the signal at the distal tip reducing the resolution of mapping of supero paraseptal APs. The aid of high resolution mapping should be considered to improve safety and efficacy.

Parahisian Atrial Tachycardia: Cryoablation from the Aortic Cusp

A 29-year-old female patient with Ebstein anomaly was referred to our division for drug-resistant symptomatic wide-complex tachycardia. Her preprocedural electrocardiograms showed a sinus rhythm without delta wave and a wide-complex short RP tachycardia with a rate of 150 bpm during palpitation. During conventional electrophysiologic study earliest local activation times during the tachycardia were obtained from the right parahisian region (Figure 1). A few second of initial radiofrequency ablation attempts using standard 4-mm tip radiofrequency ablation (RFA) catheter to this region resulted in cessation of the tachycardia and reversible ventriculo-atrial block. Then applying cryothermal energy using 4-mm tip cryoablation (CA) catheter (The Freezor® Cardiac CryoAblation Catheter, Minneapolis, USA) at -30 0C, cryomapping, to the initial site resulted in cessation of the tachycardia and reversible ventriculo-atrial block. The RFA catheter was advanced to the non-coronary cusp of the aortic valve which has close proximity to parahisian region [1, 2]. During application of radiofrequency energy the tachycardia stopped but significant prolongation in ventriculo-atrial conduction was detected. Lastly, cryothermal energy was applied in the non-coronary cusp. Cryomapping stopped the tachycardia without any ventriculo-atrial or atrio-ventricular block (Figure 2). Therefore, CA at -70 0C was performed with 2 freeze-thaw cycles (Figure 3 and 4). No tachycardia was induced with control programmed and burst pacing maneuvers and the patient was asymptomatic at 6-month follow-up.

Feasibility of Mitral Isthmus and Left Atrial Roof Linear Lesions Using an 8 mm Tip Cryoablation Catheter

Left atrial linear lesions are part of the ablation strategy for persistent atrial fibrillation. Radiofrequency (RF) energy is the standard energy modality. Pulmonary vein (PV) balloon cryoablation has similar success rates to RF energy but is unsuitable for linear lesions. This study assessed the feasibility and safety of left atrial linear lesions using an 8 mm tip cryoablation catheter. Consecutive patients undergoing left atrial ablation procedures for paroxysmal or persistent atrial fibrillation were studied. An 8 mm tip focal cryoablation catheter was used to create mitral isthmus and left atrial roof linear lesions and compared to a matched cohort undergoing RF ablation. A total of 21 patients (54 ± 11 years, 14 male), 15 undergoing de novo procedures using a dual console technique (simultaneous focal catheter and cryoballoon PV ablation) and 6 redo procedures (single console and focal catheter) were studied. Mitral isthmus ablation was successful in 19/21 (91%) with a mean total ablation time of 32.5 ± 2.9 minutes. Roof line ablation was successful in 18/19 with a mean ablation time of 15.6 ± 6.0 minutes. Success rates were similar but ablation times were longer than those in the matched RF group. Epicardial ablation in the coronary sinus was required less often with cryoablation (11/21 vs 17/21, P < 0.05). There were no complications. Left atrial linear lesions with an 8 mm tip cryoablation catheter are feasible and safe with a high acute success rate. The need for coronary sinus ablation is reduced. A dual console technique is possible. Long-term durability of linear lesions remains to be determined.

Slow pathway elimination for atrioventricular nodal reentrant tachycardia with the 8-mm tip cryoablation catheter: an 18-month follow-up study

The 9-French 8-mm tip cryoablation catheter confers a high rate of acute slow pathway (SP) elimination and an acceptable short-term outcome in patients with atrioventricular nodal reentrant tachycardia (AVNRT). The aim of this study was to investigate the long-term outcome of patients treated with this electrode in this indication. Eighty-two patients (female = 52) with a mean age of 54.9 ± 17.7years underwent SP elimination for typical AVNRT with the 8-mm tip cryocatheter in our institution between November 2009 to June 2012. Clinical and procedural characteristics were prospectively collected. Acute procedural success defined as AVNRT non-inducibility at the end of the procedure was obtained in 81/82 patients (98.7%). Mean procedure duration and fluoroscopy time were 74.4 ± 28.7min (range, 35-160min) and 8.7 ± 5.3min (range, 2-26min), respectively. Mean number of energy applications was 4.0 ± 2.4 (range, 2-15). No permanent atrioventricular block was observed. Transient atrioventricular block occurred in 12 patients (14.6%). Traumatic fast pathway conduction block occurred in one patient before cryoenergy delivery. Using an intention-to-treat analysis, 78 patients (95.1%) remained free of AVNRT recurrence during a mean follow-up of 17.8 ± 9.3months. This study confirmed that the 8-mm tip cryocatheter is both safe and highly effective for SP conduction elimination in patients with AVNRT and demonstrated a low recurrence rate during a long-term follow-up.

Cryoablation with an 8-mm Tip Catheter for Pediatric Atrioventricular Nodal Reentrant Tachycardia Is Safe and Efficacious with a Low Incidence of Recurrence

Cryoablation with 4- and 6-mm tip ablation catheters has been demonstrated to be safe and effective in the treatment of atrioventricular nodal reentrant tachycardia (AVNRT) in pediatric patients, albeit with a higher rate of clinical recurrence. Limited information is available regarding efficacy, mid-term outcomes, and complications related to the use of the 8-mm Freezor Max Cryoablation catheter (Medtronic, Minneapolis, MN, USA) in pediatric patients. We performed a retrospective review of all pediatric patients with normal cardiac anatomy who underwent an ablation procedure for treatment of AVNRT using the 8-mm tip Cryoablation catheter at three large pediatric academic arrhythmia centers. Cryoablation with an 8-mm tip catheter was performed in 77 patients for treatment of AVNRT (female n = 40 [52%], age 14.8 +/- 2.2 years, weight 62.0 +/- 13.9 kg). Initial procedural success was achieved in 69 patients (69/76, 91%). Transient second- or third-degree atrioventricular (AV) block was noted in five patients (6.5%). There was no permanent AV block. Of the patients successfully ablated with Cryotherapy, there were two recurrences (2/70, 2.8%) over a follow-up of 11.6 +/- 3.3 months. Cryoablation with an 8-mm tip ablation catheter is both safe and effective with a low risk of recurrence for the treatment of AVNRT in pediatric patients.

Cryoablation for Atrioventricular Nodal Reentrant Tachycardia in Young Patients: Predictors of Recurrence

Recurrence rates of atrioventricular nodal reentry tachycardia (AVNRT) after cryoablation continue to remain high despite excellent initial success rates. Our objective was to evaluate the clinical outcomes of cryoablation for AVNRT with the 4-mm and 6-mm tip cryoablation catheters in a young population and to elicit predictors of arrhythmia recurrence. We retrospectively reviewed all patients who underwent cryoablation for AVNRT at the UCSF/Stanford Pediatric Arrhythmia Center from January 2004 to February 2007. One hundred fifty-four patients (age 13.7 years (3.2-24.4)) underwent cryoablation for AVNRT of which 144 patients had inducible AVNRT (123 sustained and 21 nonsustained) and 10 had presumed AVNRT. Initial success was achieved in 95% (146/154), with no difference between the 4-mm (93%) and 6-mm (98%) cryoablation catheter tips (P = 0.15). There was no permanent atrioventricular (AV) block. Transient third-degree AV block occurred in nine patients (6%), with no difference between the 4-mm (4%) and 6-mm (9%) tip (P = 0.13). AVNRT recurrence was documented in 14% in a median time of 2.5 months (0.25-20). Recurrences were lower with the 6-mm (9%) versus the 4-mm (18%) tip, but this did not reach statistical significance (P = 0.16). With univariate analysis, a longer fluoroscopy time was the only significant factor associated with recurrence. Multivariate analysis failed to identify any significant predictor of AVNRT recurrence. Outcomes of cryoablation for AVNRT continue to be good without the complication of AV block. We could not identify any specific parameter associated with AVNRT recurrence. Further improvements in cryoablation technique will be necessary to reduce recurrences.

1090-215 Safety and efficacy of freezor MAX, a new 9FR, 8mm tip cryoablation catheter for the treatment of atrial flutter

1090-215 Safety and efficacy of freezor MAX, a new 9FR, 8mm tip cryoablation catheter for the treatment of atrial flutter

A09-1 A new improved 9FR, 8mm tip cryo ablation catheter for the treatment of atrial flutter

A09-1 A new improved 9FR, 8mm tip cryo ablation catheter for the treatment of atrial flutter

A09-1 A new improved 9fr, 8mm tip cryo ablation catheter for the treatment of atrial flutter

A09-1 A new improved 9fr, 8mm tip cryo ablation catheter for the treatment of atrial flutter

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.8 Safety and efficacy of a 7FR, 6MM tip cryoablation catheter for the treatment of atrial flutter in 98 consecutive patients

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter

2.7 Safety and efficacy of a new 9FR, 8MM tip cryoablation catheter for the treatment of atrial flutter