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

During right pulmonary vein ablation, the Circle Safe catheter is advanced through the venous system and positioned in the superior vena cava. Its distal electrodes provide diagnostic stimulation of the right phrenic nerve, while its proximal electrodes record the resulting diaphragmatic compound motor action potential (CMAP).

The recorded signal is transmitted to the Circle Safe System Console, which displays the CMAP waveform and automatically compares its amplitude with a baseline measurement obtained before ablation. This allows changes in diaphragmatic activity to be monitored throughout treatment of the right pulmonary veins.

The Circle Safe System is a diagnostic monitoring aid. It does not deliver ablation energy, modify the ablation procedure, or replace standard phrenic nerve monitoring methods used by the physician. Device function, signal stability, procedural use, and any device deficiencies or adverse events are documented during the study.

Inclusion criteria

• Male or females >18 and ≤ 85 years of age
• Subject willing to sign informed consent
• Subject is a candidate for pulmonary vein ablation for the treatment of atrial fibrillation ablation procedures therapy

Exclusion criteria

• Subjects with pacemaker or defibrillator leads placed through the vena cava
• Subjects with implantable vena cava filter
• Subjects with a contraindication to contrast dye
• Pregnant subjects
• Subjects with inadequate venous access due to prior vein thrombosis or indwelling chronic ports or catheters
• Subjects participating in another clinical trial that has not reached the follow-up time point to primary endpoint assessment
• Subjects with known neuromuscular disease or other medical history (i.e trauma, surgery) that could have impacted diaphragmatic function