Prevention of serious air embolism during cryoballoon ablation; risk assessment of air intrusion into the sheath by catheter selection and change in intrathoracic pressure: An ex vivo study.

The amount of air intrusion increased when using catheters with complicated tip shapes and thin outer diameters and when the magnitude of negative pressure in the sheath increased. The sheath-in-sheath technique may be an effective countermeasure.