First-in-Human Study of the Circle Safe System for Diaphragm Response Monitoring During Pulmonary Vein Ablation

The objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation. The main questions it aims to answer are: * Can the Circle Safe System consistently stimulate the phrenic nerve and record a stable electrical response from the diaphragm? * Can it reliably display changes in the diaphragm's response during ablation? * What device-related or procedure-related medical problems occur during the study? There is no comparison group. All participants will undergo their planned pulmonary vein ablation while the Circle Safe System is used during treatment of the right pulmonary veins. Participants will: * Complete standard assessments before the procedure * Have the Circle Safe catheter placed in the superior vena cava during the ablation procedure * Have their phrenic nerve stimulated and their diaphragm response monitored using the Circle Safe System * Be evaluated for device-related and procedure-related safety events through hospital discharge