Statistical analysis
We estimated that 32 patients would be needed to find a 10-ms difference
in the QRS duration between MPP and MPP-FOI with an α = 0.05 and a
statistical power (1-β) of 80%, assuming a standard deviation of 20 ms
for pair differences.
Categorical variables, represented as proportions, were compared using
the χ² test. Continuous variables, after confirming their normal
distribution (QQ plot), were expressed as the means and standard
deviations, and between-group comparisons were made using Student’st -test. Linear mixed-effects models with a repeated-measures
structure were used to assess differences in the QRS duration,
echocardiographic measures, and biventricular activation times (using
ECGI) across the three pacing modes. The correlation between the
duration of the QRS complex (ECG) and activation time (ECGI) was
assessed using the Pearson coefficient. A two-tailed P< 0.05 was deemed statistically significant. All statistical
analyses were conducted using SPSS software v22.0 (SPSS Inc., USA) or R
v3.6.1 (R Project for Statistical Computing; Vienna, Austria).