Pranav Bhagirath

96 Chapter 5 Statistical analysis Statistical analysis was performed using PASW Statistics (Version 17.0). Continuous variables were expressed as mean ± standard deviation. Normality testing was performed using the Shapiro-Wilk test. Normally distributed data were compared using the independent Student’s t-test. The χ 2 test was used to compare the proportions between the groups. Pearson’s r was used to perform correlation analysis. A p < 0.05 was considered to be statistically significant. RESULTS Patient population A total of 25 patients were included in the study. The majority of the patients were male (n=20) and had persistent AF (n=15). There were no significant differences in the total AF duration amongst the paroxysmal AF group (2333 ± 1817 days) and the persistent AF group (1853 ± 1333 days) (p=0.48). Average patient follow-up after the repeat procedure was 664 ± 245 days. Additional baseline characteristics are summarized in table 1 . Catheter ablation outcome Electro-anatomic mapping during the repeat procedure demonstrated that none of the patients had complete circumferential isolation of all PV’s. The majority of the repeat ablations (61%) were caused by electrical reconnection of the right inferior PV (RIPV). Fourteen patients (56%) had AF recurrence after the first repeat procedure. From these patients, eight (57%) underwent a third ablation procedure. The other six patients were treatedwith anti-arrhythmic drugs. Therewas no relation between the duration (p=0.51) and nature (paroxysmal or persistent) (p=0.62) of AF on the probability of AF recurrence. Left atrial remodeling There was no correlation between the pre-(index)procedural LA volume index (LAVi) and LASP (Pearson’s r=0.107, p=0.61). Furthermore, post-(index)procedural LAVi and LASP also did not show a correlation (Pearson’s r=0.266, p=0.20). Nine cases showed discordance between volumetric and geometric remodeling ( figure 2 ).