Data extraction
Data from eligible studies were extracted in a predesigned Microsoft
Office Excel 2007 form by two independent reviewers (I.A. and M.K.) and
crosschecked for any disagreements, which were resolved after consensus
with a senior (G.G.). In case of eligible studies that did not clearly
report the primary outcome of interest, we contacted authors
electronically (via email) to obtain the required data. For one study
that provided effect size as median with interquartile range (IQR),
median was used as mean and the standard deviation was obtained from IQR
(standard deviation=IQR/1.35). In 10 out of 17 studies the endpoint was
defined as AF recurrence, whereas in the other 6 studies the endpoint
included atrial tachyarrhythmias (AF, atrial flutter, atrial
tachycardia). Furthermore, in the majority of eligible studies (11/16)
the LA-PLSsys was measured in sinus rhythm, whereas, accordingly to Hang
et al.[9], peak and average systolic strain and
strain rate showed no statistical difference between sinus rhythm and AF
at baseline echocardiographic parameters. It should be noted that all
strain measurements were performed before the catheter ablation
procedure.