The value of measured partial oxygen pressure during pulmonary vein closure and the relationship with the diameter of the closed vein in patients with cryoablation.

Abstract

Aim: The aim of this study was to investigate the value of partial oxygen pressure (PO₂) changes measured in the left atrium (LA) during transient pulmonary vein (PV) closure in patients undergoing cryoablation and its relationship with the diameter of the closed PV.

Methods: The study was carried out on a total of 25 cases. The grouping of PVs was made separately as the left superior, left inferior, left common, right superior, right inferior, right common and total PVs. PV measurement was made from angiographic images obtained after the cryoablation balloon was inflated and opaque. From the LA, the difference between the PO₂ values in the blood gases obtained before and during the temporary closure of each PV was evaluated as the PO₂ change. The difference of the lowest temperature reached during the closing of each PV from -36°C was termed the heat difference. The relationship of PO₂ change with PV diameter and the heat difference were investigated.

Results: There was no significant relationship between any of the PV diameters and PO₂ changes (p > 0.05). There was a significant relationship between heat differences and PO₂ changes in the left superior (p = 0.011), right superior (p = 0.049), right 'common' (p = 0.037) and total PVs (p = 0.001), but there was no significant relationship between heat differences and PO₂ changes in the left inferior, left 'common' and right inferior PVs (p > 0.05).

Conclusion: In the light of these data, PO₂ change could demonstrate the success of cryoablation, and was related with the cooling degree, but not with the PV diameter.