title: Novel method for earlier detection of phrenic nerve injury during cryoballoon applications for electrical isolation of pulmonary veins in patients with atrial fibrillation.
abstract: Diaphragmatic electrogram recording during cryoballoon ablation (CB-A) of atrial fibrillation is commonly used to predict phrenic nerve palsy (PNP).
  
  
  
  The purpose of this study was to investigate a novel method for predicting PNP at an earlier stage to prevent sustained PNP.
  
  
  
  A total of 197 patients undergoing CB-A were enrolled. We attempted to detect PNP using fluoroscopic images of diaphragmatic contractions and by monitoring diaphragmatic compound motor action potentials (CMAPs) provoked by superior vena cava (SVC) and left subclavian vein (LCV) pacing during CB-A for bilateral pulmonary veins (PVs). Pacing of the SVC and LCV was performed at 2 outputs, 1 exceeding the pacing threshold by 10% (MIN) and the other at maximum output (MAX). The time from freezing to the initiation of PNP, values of the CMAP amplitude, and severity of PNP were compared for the 2 outputs.
  
  
  
  There was a significant difference in the time from freezing to initiation of PNP between MIN and MAX pacing (25.7 ± 5.7 vs 81.3 ± 7.4 seconds, P<.01). CMAP amplitudes also differed significantly (0.71 ± 0.39 vs 1.13 ± 0.42, P<.0001). SVC/LCV pacing with MIN output was able to detect PNP significantly earlier than MAX (27 ± 8 vs 91 ± 12 seconds, P<.01), and the time to PNP recovery was significantly shorter for the MIN output (20.2 ± 8.88 hours vs 4.8 ± 1.6 months, P<.001).
  
  
  
  Pacing the SVC and LCV with lower output detect PNP significantly earlier than maximal output pacing and leads to recovery from PNP on the order of hours postprocedure rather than months.
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan. Electronic address: okishige@yo.rim.or.jp.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Okishige
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Aoyagi
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Naohiko
authors.initials: N
authors.lastname: Kawaguchi
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Katoh
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Mitsumi
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Kurabayashi
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Mitsutoshi
authors.initials: M
authors.lastname: Asano
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Kentarou
authors.initials: K
authors.lastname: Gotoh
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Shimura
authors.affiliation: Heart Center, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Yamauchi
authors.affiliation: Department of Neurology, Yokohama-City Bay Red Cross Hospital, Yokohama City, Japan.
authors.forename: Toshirou
authors.initials: T
authors.lastname: Kanazawa
authors.affiliation: Arrhythmia Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Sasano
authors.affiliation: Arrhythmia Center, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
mesh_terms: D000200:Action Potentials; D000368:Aged; D001281:Atrial Fibrillation / Q000601:surgery*; D002304:Cardiac Pacing, Artificial; D003452:Cryosurgery / Q000009:adverse effects* / Q000295:instrumentation; D003964:Diaphragm / Q000293:injuries; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D059348:Peripheral Nerve Injuries / Q000175:diagnosis* / Q000209:etiology; D010791:Phrenic Nerve / Q000293:injuries*; D011667:Pulmonary Veins / Q000601:surgery*
keywords: Atrial fibrillation; Catheter ablation; Cryoballoon; Phrenic nerve palsy