Electro-anatomical mapping of the left atrium before and after cryothermal balloon isolation of the pulmonary veins

Abstract

Introduction The 28 mm cryoballoon catheter is a device used for pulmonary vein isolation (PVI). The aim of this study was to evaluate the extent of the ablation in the antral regions of the left atrium. Methods and Results Eighteen patients with drug refractory, symptomatic, paroxysmal AF were enrolled. A 3D electroanatomic reconstruction of the left atrium was made before and after successful PVI with the 28 mm cryoballoon. Markers were placed at the ostium. Sixteen patients were mapped. Fourteen patients had 4 veins each, and 2 patients had a common ostium of the left sided veins. All separate ostia were isolated in the antral region. The two common ostia showed ostial isolation. There was a significant difference in vein size between the common (29 and 31 mm) and the separate ostia (19±4 mm) (p<0.01). The performance of an additional segmental ablation if balloon PVI did not eliminate all electrical activity, did not influence the extent of the ablation. The earliest left atrial activation during sinus rhythm was located in the superior septal region before ablation in all patients. After ablation, two patients showed a substantial downward shift towards the middle and inferior septal region respectively (NS). Four patients demonstrated a slight downward shift of the first activation.Conclusions In cryoballoon PVI, the majority of the veins undergo antral isolation. Veins with a diameter larger than the balloon, are isolated ostially. In individual cases, the left atrial activation sequence appears to be altered after ablation.Keywords Ablation . Arrhythmia . Cryoballoon . Cryoablation . Catheter ablation . Tachyarrhythmias . Atrial fibrillation . Pulmonary veins IntroductionThe cryothermal balloon, or cryoballoon, is a novel technology, developed for pulmonary vein (PV) isolation. It is a catheter based device with the potential of performing a circumferential ablation, thus isolating the PV muscular sleeves in a limited number of applications. Since cryothermia causes no PV stenosis [1][2][3] the ablation can safely be performed at the ostial level of the pulmonary vein, but the question remains to what extent cryoballoon ablation modifies the left atrial substrate. After a large experience in animal testing was achieved by several authors [4][5][6][7] the first human results are promising as a treatment for paroxysmal atrial fibrillation (AF) [8]. The aim of this study was to evaluate the effect of the cryothermal balloon on the antral regions of the left atrium. Methods InclusionPatients with documented symptomatic paroxysmal AF despite antiarrhythmic drugs, at two or more occasions,

Mapping and Isolation of the Pulmonary Veins Using the PVAC Catheter

“…We hypothesize that the use of the PVAC catheter by its design results in general in an ostial ablation. This is also observed with the HDMA catheter and the cryoballoon 9,10 . However, in case of a common ostium or when early branching is present, the guidewire can be positioned in different side branches of the PV resulting in different PVAC positions creating overlapping ablation lines that as a whole result in a more wide circumferential PV isolation.…”

Pulmonary venous isolation by antral ablation with a large cryoballoon for treatment of paroxysmal and persistent atrial fibrillation: medium-term outcomes and non-randomised comparison with pulmonary venous isolation by radiofrequency ablation

“…When the 23 mm balloon was used, the veins were found to be isolated at the level of the ostium, whereas use of the 28 mm larger balloon results in the formation of much wider, circumferential and antrally located lesions 18 19. In cadaveric studies, the right phrenic nerve is not uncommonly less than 2 mm away from the anterior aspect of the proximal segment of the right superior pulmonary vein 20.…”

Pulmonary Vein Antrum Isolation and Terminal Part of the P Wave

“…Lesions of the Bachmann bundle could occur during PVAI, due to its proximity to the antral region of the right superior PV in some cases 27 . In a recent study evaluating the electro‐anatomical mapping of the LA before and after PVAI performed with cryothermal balloon, 28 at least two of the 16 patients included had a modification of LA activation after PVAI, probably linked to lesions of the Bachmann bundle. Such lesions modify the preferential conduction route between the atria and could also be responsible for modifications of the Ptf.…”