Sample size calculation
Compared with Group C, GLS in Group E improved after 24 h of Esmolol application in the previous preliminary test [(-11.54 ± 4.67) VS (-8.72 ± 4.23)], and hemodynamics did not deteriorate. The sample size was calculated using PASS 14.0 software, and the parameters were set as: β ≤ 0.1; power (1-β) = 90%; and significance level bilateral α = 0.05. The calculated sample size was 46 cases in each group, and 50 were included in each group according to the shedding rate of 20%.