Diaphragmatic electromyography during cryoballoon ablation: a novel concept in the prevention of XXXX .

@entity129 @entity4589 @entity235 @entity955 @entity912
BACKGROUND: @entity912 is the most frequent complication associated with cryoballoon ablation for @entity955 . To date, no preventive strategy has proved effective. OBJECTIVE: We sought to assess the feasibility of diaphragmatic electromyography during cryoballoon ablation, explore the relationship between altered signals and @entity129 , and define characteristic changes that herald @entity912 . METHODS: Cryoballoon ablation was performed in the right superior pulmonary vein or superior vena cava in 16 mongrel @entity235 weighing 37.7    2.4 kg, at sites determined by phrenic nerve capture. During ablation, the phrenic nerve was paced at 60 bpm from the superior vena cava while recording diaphragmatic compound motor action potentials (CMAPs) by esophageal decapolar catheters. Diaphragmatic excursion was monitored by fluoroscopy and abdominal palpation. RESULTS: Before ablation, the CMAP amplitude was 592 (interquartile range 504, 566)  V, initial latency 21.5    4.2 ms, peak latency 64.7    21.1 ms, and duration 101.7    13.3 ms. @entity912 was obtained in all @entity235 62    34 seconds into the cryoapplication. The CMAP amplitude decreased exponentially, with no patterned changes in latencies and duration. Discriminatory analyses by receiver-operating curve characteristics identified a 30% reduction in CMAP amplitude as the most predictive cutoff value for @entity912 (c-statistic 0.965; P<.0001). This criterion presaged @entity4589 , as detected by abdominal palpation, by 31    23 seconds. CONCLUSION: Diaphragmatic electromyographic signals could be reliably recorded during cryoballoon ablation. An exponential decrease in CMAP amplitude precedes @entity4589 , with a 30% reduction yielding the best discriminatory potential. A promising safety margin was detected, which merits prospective validation.
