Intracardiac ablation for atrioventricular nodal reentry tachycardia using a 6 mm distal electrode cryoablation catheter: Prospective, multicenter, North American study (ICY‐AVNRT STUDY)

Abstract

Cryoablation for AVNRT using a focal 6-mm catheter was safe and effective. It resulted in a low risk of recurrence over 6 months of follow-up with no incidence of AV block requiring permanent pacing.

Does cryomapping warrant a safety in the subsequent therapeutic cryoablation?

“…One of the important therapeutic characteristics of cryoablation is an ability of creation of reversible impairment to the myocardial tissue by applying a cryothermal energy at a halfway low temperature (−30°C) (cryomapping). Even with the application of rapid cooling to −75°C or less, the freezing wavefront advances slowly, thus allowing for time to discontinue freezing and avoiding the creation of permanent injury . In the recent ICY‐AVNRT study in which slow pathway cryoablation was attempted in 397 patients, there was no case with complete AV block requiring permanent pacing reported …”

“…Even with the application of rapid cooling to −75°C or less, the freezing wavefront advances slowly, thus allowing for time to discontinue freezing and avoiding the creation of permanent injury . In the recent ICY‐AVNRT study in which slow pathway cryoablation was attempted in 397 patients, there was no case with complete AV block requiring permanent pacing reported …”

“…Even with the application of rapid cooling to −75°C or less, the freezing wavefront advances slowly, thus allowing for time to discontinue freezing and avoiding the creation of permanent injury. 10 In the recent ICY-AVNRT study in which slow pathway cryoablation was attempted in 397 patients, there was no case with complete AV block requiring permanent pacing reported. 10 In this issue of the Journal of Cardiovascular Electrophysiology, This study demonstrated not only the effectiveness and safety of cryoablation targeting the earliest activation site in ATPsensitive atrial tachycardia but the usefulness of cryomapping in determining the target ablation site while avoiding the adverse AV conduction impairment.…”

“…10 In the recent ICY-AVNRT study in which slow pathway cryoablation was attempted in 397 patients, there was no case with complete AV block requiring permanent pacing reported. 10 In this issue of the Journal of Cardiovascular Electrophysiology, This study demonstrated not only the effectiveness and safety of cryoablation targeting the earliest activation site in ATPsensitive atrial tachycardia but the usefulness of cryomapping in determining the target ablation site while avoiding the adverse AV conduction impairment. 11 Ablation targeting at the earliest activation site per se is the same as used in the radiofrequency catheter ablation for the same tachycardia.…”

Look and you shall find: Perils along the road after slow pathway ablation for AV nodal reentry tachycardia

“…Atrial fibrillation, focal atrial tachycardia, atrial flutter, and AV reentry tachycardia were noted in 19%, 8%, 6%, and 4% patients, respectively. The incidence of complete AV block during AVNRT ablation has decreased since the procedure's inception, and is now less than 0.5% . However, late AV block has been documented in the postablation period .…”