Introduction: Cryoballoon pulmonary vein (PV) isolation requires tissue contact and obstruction of passing blood flow to achieve permanent, contiguous lesions. Although fluoroscopy has enabled real-time visual assessment of circumferential contact for cryoballoons, this approach exposes patients and staff to harmful radiation. Thus, there is a need for safer sensing strategies to locally assess interfacial PV-cryoballoon contact.
Methods: : An array of 10 impedance-based contact sensors was affixed to the surface of a 23 mm Arctic Front® Cryoballoon in a staggered (Fig. 1A, B). Balloon inflation and cryoablation were performed in the superior vena cava and in the PVs (Fig. 1C).
Results: A total of 30 balloon inflations were performed in three swine. There was concordance in the assessment of contact quality between the data from the sensors and contrast injection in all these trials. A rise in impedance by a factor of 30.9±3.7 above baseline was observed during cryotherapy for sensors in optimal contact with tissue.
Conclusions: Impedance-based contact sensors on the cryoballoon surface provide an effective means for evaluating mechanical interactions at the balloon-tissue interface during balloon positioning and cryoablation.