Catheter Cryoablation of Supraventricular Arrhythmias:

Abstract

Cryothermy has potential advantages over RF energy for catheter ablation, including reversibility of lesion formation, catheter stability, and less procedural discomfort. Cryoablation procedures were performed in 14 patients with atrioventricular reentrant tachycardias (AVNRTs), 13 patients with accessory pathway (AP)-mediated tachycardias, and 5 patients with atrial fibrillation. The numbers of energy applications, pain scores, procedural times, and outcomes were recorded and compared with age- and sex-matched patients undergoing similar RF procedures. Cryoablation was successful in 26 of 32 patients (11/14 AVNRT, 10/13 AP, 5/5 AF) compared with 30 of 32 undergoing RF procedures, with similar numbers of energy applications and procedural times. Cryothermy was painless in all patients, and the overall procedural discomfort was significantly less than in patients treated with RF (1.3 +/- 2.2 vs 6.1 +/- 3.5). In patients with anteroseptal pathways, cryomapping successfully identified safe sites to target the delivery of energy. Cryothermy is a painless and safe alternative to RF. It may be particularly useful for catheter ablation of patients with pathways close to the atrioventricular node.

Radiofrequency catheter ablation in infants and children

“…(22) Patient discomfort is also less during cryoapplication. (23) The acute success rate for cryoablation for AVNRT is comparable with RFCA (94% vs. 96%), but the recurrence rate is higher (12% vs. 6%). (24) The total success rate for APs is lower than RFCA (75% vs. 92%) but it is comparable for midseptal and anteroseptal APs (i.e.…”

Catheter Cryoablation

“…In contrast to RFCA, cardiac cryoablation is not associated with patient discomfort. [26][27][28] Thus, for select procedures associated with substantial patient discomfort, the use of cryoablation may theoretically result in lower anesthetic and analgesic requirements. [26][27][28] This is especially relevant for electrophysiology laboratories that do not use general anesthesia.…”

Transvenous radiofrequency catheter ablation of atrioventricular nodal reentrant tachycardia and its pitfalls: A rationale for cryoablation?

“…Because the target site is in close proximity of the compact AV node, continuous fluoroscopy during application is necessary to be sure that catheter dislodgement does not occur with the risk of causing inadvertent complete AV block. This limitation of catheter stability is even further compromised by pain during energy delivery [19]. Although non-fluoroscopic equipment and other energy sources are expensive, it can lead to less radiation exposure, and after a learning curve also to shorter procedure times [8 -10].…”

“…Furthermore, an increased risk exists of causing a right bundle branch block or inadvertent complete heart block, especially in the treatment of tachyarrhythmias in Koch's triangle, as these arrhythmias are located in close proximity to the compact AV node, and lesions created by RF energy are immediately irreversible. Finally, RF ablation can be painful, especially during energy delivery close to the os of the coronary sinus or the junction of the right atrium and IVC [19]. Considering the above limitations, alternative energy sources have been developed, of which cryoablation seems to be promising [25 -31].…”