Statistics
Descriptive results are displayed as mean±SEM or median (interquartile
range) for continuous variables, according to the normality of the
distributions. Categorical data are described as number (percentage).
Continuous variables were compared using the paired Student t-test.
Receiver operating characteristic (ROC) curves were constructed to
determine the cut-off value, sensitivity (Se), and specificity (Spe) of
the delta PR interval. Two-sided p values <0.05 were
considered statistically significant. Statistical analyses were
performed using SPSS Inc. Released 2007. SPSS for Windows, Version 16.0.
Chicago, SPSS Inc.