Enlargement of Catheter Ablation Lesions in Infant Hearts With Cryothermal Versus Radiofrequency Energy

Abstract

Background-Radiofrequency catheter ablation in immature hearts has been associated with marked enlargement of lesions over time, with potential for related late adverse events. It remains unknown whether cryothermal ablation lesions display a similar pattern of growth. Methods and Results-Ablation lesions (nϭ384) were performed in 32 infant miniature swine in right and left atria, ventricles, and atrioventricular (AV) grooves preselected by a randomized factorial design devised to compare radiofrequency and cryothermal lesions produced by 7F 4-mm electrode-tip catheters. Animals were euthanized acutely or at 1, 6, or 12 months, according to the randomization scheme. The miniature swine weighed 8.8Ϯ1.2 kg and were 63Ϯ13 days of age at time of ablation. The minimum temperature during cryoablation was Ϫ79.8Ϯ3.4°C and the average temperature during radiofrequency ablation was 54.4Ϯ5.5°C. On morphometric analyses, no differences in the rate of growth of ablation lesions were noted between the 2 energy modalities in atria (Pϭ0.

2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death

“…należy unikać dożylnego podawania werapamilu, ponieważ lek ten może być przyczyną ostrej dekompensacji hemodynamicznej [476]. U małych dzieci powikłania ablacji przezcewnikowej wydają się częstsze, a ponadto istnieją obawy o konsekwencje w fazie dalszego wzrostu po wywołaniu uszkodzeń termoablacyjnych lub krwioablacyjnych w mięśniu sercowym [475,[485][486][487]. Idiopatyczny VT i złożone PVC u dzieci zwykle ustępują samoistnie w ciągu miesięcy do lat [471].…”

Don't Forget to Gather the Evidence

“…3 These include reversibility during testing, smaller lesion size, minimal effects on coronary arteries without reported stenosis, and minimal endocardial disruption with less thrombus formation. 4 -6,12,15 Many of these features were highlighted in the current study by Khairy et al 1 …”

“…4 When the data were in, they actually demonstrated that there were no differences between the late effects of CRYO and RF on developing myocardium, and both techniques led to longterm lesion growth and invasion of scar tissue into surrounding myocardium. 1 …”

Catheter Cryoablation

“…[1][2][3]16,18 However, it is important to note that when applied to immature myocardium, the rate of expansion of cryoablation lesions is similar to RFCA. 19 In addition, cryothermal ablation lesions are associated with minimal endothelial surface disruption and a lesser degree of platelet and the coagulation cascade activation when compared with RFCA. 2,20,21 Preclinical studies have demonstrated a significantly lower incidence of overlying thrombus (30.1% versus 75.8% despite the use of aspirin and heparin), and a lesser thrombus volume with cryothermal ablation compared with RF.…”