P-SAECG and atrial remodeling
PWD is an electrophysiological parameter that reflects complete atrial conduction. Studies11-13 have reported that P-SAECG findings are closely related to AF recurrence after CA. Okumura et al.12 performed P-SAECG before and after CA (n=51) in patients with paroxysmal and persistent AF. Patients with successful CA had a more significant shortening of the PWD (from 146 ± 13 to 136 ± 12 ms; P <0.01) than those in whom recurrence occurred (from 167 ± 15 to 157 ± 15 ms; P= 0.18). Ogawa et al.11reported a significant reduction in PWD (from 161 ± 7 to 151 ± 8 ms; ΔPWD 10 ± 7 ms; P <0.0001) after CA in patients with paroxysmal and persistent AF (n=27), although they observed no significant shortening in PWD in patients with AF recurrence. Masuda et al.13 performed P-SAECG before and 1 day after CA (n=88) in patients with paroxysmal AF. Although there were no differences in pre-CA P-SAECG findings, AF recurrence was significantly more common in patients with a long PWD and low RMS20 1 day after CA than those without them (54% vs. 19%, P=0.001). These reports suggest that improvement in atrial conduction parameters could be associated with a reduced recurrence rate after CA because ALP is a marker of abnormal atrial electrical properties such as intra-atrial or inter-atrial conduction disturbance.
In our study, we evaluated a large number of patients with paroxysmal AF and focused on the prediction of AF recurrence based on positive ALP before CA. Consequently, the rate of positive ALP before CA (a long PWD and a low RMS20) was significantly higher in the Recurrence group than in the Non-recurrence group. These results suggest that the parameter of positive ALP on P-SAECG could be used to detect the electrical remodeling.