Abstract
BACKGROUND: Diaphragmatic compound motor action potential (CMAP) monitoring helps prevent phrenic nerve palsy during cryoballoon ablation (CBA) for atrial fibrillation. METHODS: This retrospective analysis included 95 patients who had undergone CBA. Phrenic nerve pacing was performed via the distal electrode of a BeeAT catheter positioned in the right subclavian vein, with CMAPs recorded from the most proximal electrode in the subdiaphragmatic inferior vena cava. RESULTS: CMAP amplitude was unaffected by patient body habitus (mean: 1.14 ± 0.58 mV; CMAP-to-ventricular wave ratio: 8.76). CONCLUSIONS: This technique provides stable, well-defined signals with minimal artifacts, enhancing the reliability of CMAP monitoring during CBA.