Miyazaki Shinsuke, Hachiya Hitoshi, Taniguchi Hiroshi, Nakamura Hiroaki, Ichihara Noboru, Usui Eisuke, Kuroi Akio, Takagi Takamitsu, Iwasawa Jin, Hirao Kenzo, Iesaka Yoshito
Cardiovascular Center, Tsuchiura Kyodo Hospital, Tsuchiura, Ibaraki, Japan.
Heart Rhythm Center, Tokyo Medical and Dental University, Tokyo, Japan.
J Cardiovasc Electrophysiol. 2015 Jun;26(6):622-8. doi: 10.1111/jce.12671. Epub 2015 May 1.
Left phrenic nerve injury (PNI) can occur during cryoballoon ablation of the left pulmonary veins (PVs). This study aimed to evaluate the feasibility of monitoring the bilateral phrenic nerve function during cryoballoon ablation of atrial fibrillation (AF).
Fifty consecutive paroxysmal AF patients undergoing cryoballoon ablation using one 28-mm second-generation balloon were prospectively enrolled. Bilateral diaphragmatic compound motor action potentials (CMAPs) were obtained from modified surface electrodes by pacing from the bilateral subclavian veins, and monitored during 3-minute cryoballoon applications at the ipsilateral PVs.
One hundred ninety of 202 PVs were successfully isolated exclusively using 28-mm cryoballoons. CMAPs could be obtained in all except 3 cases with catheter inaccessibility in the left subclavian vein. The left and right CMAP amplitudes were similar at baseline (1.04 ± 0.41 mV vs. 1.01 ± 0.43 mV, P = 0.49). Among 105 left and 132 right PV applications while monitoring CMAPs, 2 (1.9%) and 13 (9.8%) applications were interrupted for a decreased CMAP amplitude (P = 0.01). Among them, CMAPs decreased due to right PNI in 4 applications/patients and to catheter dislodgement in the remaining applications. PNI remained in 1 and recovered in the remaining 3 patients one day after the procedure. Applications without requiring interruptions exhibited no significant CMAP amplitude changes throughout the applications, and the time-course pattern was similar between the bilateral CMAPs (P = 0.292).
A stable bilateral diaphragmatic CMAP could be similarly obtained during cryoballoon applications in the vast majority of patients. Monitoring CMAPs might be useful to anticipate not only right but also left PNI during cryoballoon ablation.
左膈神经损伤（PNI）可能发生在左肺静脉冷冻球囊消融术中。本研究旨在评估在心房颤动（AF）冷冻球囊消融术中监测双侧膈神经功能的可行性。
前瞻性纳入50例连续接受使用一个28毫米第二代球囊进行冷冻球囊消融的阵发性AF患者。通过从双侧锁骨下静脉起搏，从改良的表面电极获取双侧膈肌复合运动动作电位（CMAP），并在同侧肺静脉进行3分钟冷冻球囊应用期间进行监测。
202个肺静脉中的190个仅使用28毫米冷冻球囊成功隔离。除3例左锁骨下静脉导管无法到达的病例外，所有病例均能获得CMAP。基线时左右CMAP振幅相似（1.04±0.41mV对1.01±0.43mV，P = 0.49）。在监测CMAP的105次左肺静脉和132次右肺静脉应用中，2次（1.9%）和13次（9.8%）应用因CMAP振幅降低而中断（P = 0.01）。其中，4次应用/患者因右侧PNI导致CMAP降低，其余应用因导管移位导致CMAP降低。术后1天，1例患者PNI持续存在，其余3例患者恢复。无需中断的应用在整个应用过程中CMAP振幅无显著变化，双侧CMAP的时间进程模式相似（P = 0.292）。
在绝大多数患者的冷冻球囊应用过程中，可类似地获得稳定的双侧膈肌CMAP。监测CMAP不仅可能有助于预测冷冻球囊消融术中的右侧PNI，也有助于预测左侧PNI。
