Statistical analysis
Data were shown as means ± standard deviations for continuous variables
and percentages for categorical variables. Pearson’s correlation
coefficients were used to assess relationships between peak EL in ED,
LD, and Sys (ED-EL, LD-EL, and Sys-EL, respectively) and age, height,
weight, sex, comorbidities, heart rate (HR), BP, laboratory data, and
echocardiographic parameters. A stepwise multivariate linear regression
was performed to analyze independent variables that correlated with
ED-EL, LD-EL, and Sys-EL. All statistical analyses were performed using
SPSS software version 20 (IBM Inc., Chicago, IL, USA). A P value less
than 0.05 was considered to be significant.