**5. Conclusions**

was significantly higher in the patients with residual AMF than in those without (2.3±1.2 vs.

The incidence of non-PV AMF was significantly higher in the patients with pacing inducible AF than in those without [69 % vs. 47 %, p=0.032). The residual AMF were significantly higher in the patients with pacing-inducible AF than in those without (67 % vs. 29 %, p<0.001).

The mean follow-up period after the CA was 937 days. The follow-up ratio was 106 out of 117 patients (90.6 %) at one year and 86 of 117 patients (73.5 %) at two years after the CA. In-hospital AF episodes were observed in 17 of 117 (14.5 %) patients, and a long-term AF recurrence was observed in 42 of 117 (35.9 %) patients. AT episodes after the CA were observed in 31 of 117 patients (26.4 %), and those were only observed within 3 months after the CA in 11 of 31 patients (35.4 %). AT episodes coexisted with the AF episodes in 16 of 31 patients (52 %). In the multivariable analysis, the AF duration (1.01 (1.00–1.02), p=0.012), LA volume (1.01 (1.01–1.02), p=0.006), and residual AMF (3.95 (1.32–11.8), p=0.004) were independent risk factors for recurrent AF. Figure 13 demonstrates the AF recurrence ratio in the patients with and without residual AMF. AF episodes after the CA were significantly greater in the patients with residual AMF than in those without (50 % vs. 26 %, p=0.002). The result of the study demonstrated that the residual AMF was a useful predicting parameter for the outcome of CA, and the clinical course was impressively favorable in patients without residual AMF (AF recurrence after initial session at two years was 26%). (58.1 %). At the end of the ablation, residual AF was still

**Figure 13.** The AF recurrence ratio in the patients with and without residual arrhythmogenic foci during the follow-up. Residual foci were observed in 48 of 117 patients (41 %). The AF free ratio between both groups was compared by a log rank analysis, and AF episodes after the CA were significantly higher in the patients with residual foci than in those

After only a PV isolation, AF was no longer inducible in approximately one fifth of the patients with a favorable outcome even though they underwent a less aggressive intervention. This information might allow us to reduce the number of unnecessary additional RF applications during CA. On the other hand, non-PV foci were also highly confirmed even in patients with

without (50 % vs. 26 %, p=0.002). The mean follow-up period was 937 days.

3.0±1.2, p=0.041).

70 Abnormal Heart Rhythms

inducible in 37 of 117 patients (31.6 %).

AMF could be involved in mechanism of the AF development. In addition, atrial anatomical structure such as left atrial roof shape, left lateral ridge, and Marshall vein provided us with an understanding of the arrhythmogenicity of the PVs and non-PVs in patients with AF. Because the presence of residual AMF is associated with increased AF recurrence after ablation, the information of AMF is useful for determining the appropriate strategy of ablation for AF.
