Open AccessPositioning an ECG electrode to the dorsal side can record higher amplitude of CMAPs during cryoballoon ablation
Author(s) -
Mizukami Kazuya,
Homma Tsuneaki,
Natsui Hiroyuki,
Kato Mizuki,
Otsu Keisuke,
Takenaka Takashi,
Sato Minoru
Publication year - 2020
Publication title -
journal of arrhythmia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.463
H-Index - 21
eISSN - 1883-2148
pISSN - 1880-4276
DOI - 10.1002/joa3.12314
Subject(s) - medicine , phrenic nerve , ablation , dorsum , radiofrequency ablation , diaphragmatic breathing , anesthesia , anatomy , cardiology , respiratory system , alternative medicine , pathology
Purpose Phrenic nerve injury (PNI) is one of the important complications during cryoballoon (CB) ablation. Recording diaphragmatic compound motor action potentials (CMAPs) during CB ablation can predict PNI. CMAP monitoring may be inaccurate when CMAP amplitudes are low. We examined the effect of positioning an electrocardiography (ECG) electrode at the dorsal side. Methods We retrospectively analyzed the cases of 197 consecutive patients who underwent CB ablation for pulmonary vein isolation (PVI) (April 2016 to December 2018) at our institution. CMAP amplitudes were monitored using two recording methods just before cryoapplication. (a) Conventional method: right‐arm ECG electrode positioned 5 cm above the xiphoid on the ventral side; left‐arm ECG electrode positioned along the costal margin. (b) Our original method: right‐arm electrode positioned 5 cm above the xiphoid on the dorsal side; left‐arm electrode positioned along the costal margin. Results The CMAP amplitude during right phrenic nerve pacing was significantly higher at the dorsal side than the ventral side (0.80 ± 0.31 mV vs 0.66 ± 0.29 mV, P < .01). Similarly, the CMAP amplitude during left phrenic nerve pacing was significantly higher at the dorsal side than the ventral side (0.92 ± 0.39 mV, 0.73 ± 0.37 mV, P < .01). PNI occurred in six patients (3.0%); three patients experienced transient PNI, another three patients experienced persistent PNI, and none developed permanent PNI. Conclusions CMAP amplitudes were significantly high at the dorsal side compared to the ventral side. Monitoring phrenic nerve function using an ECG electrode at the dorsal side is a simple and easy procedure.