Methods
left ventricular systolic force
This study was a single-center, prospective, and randomized controlled study. A total of 100 SIC patients with a heart rate more than 100/min, admitted to the Intensive Care Department of Tianjin Third Central Hospital from March 1, 2020 to September 30, 2021, were selected as the research subjects. They were randomly divided into the Esmolol group (Group E) and the conventional treatment group (Group C), each with 50 cases. The target heart rate of patients in Group E was controlled between 80/min and 100/min. Speck-tracking echocardiography (STE) and pulse indicating continuous cardiac output monitoring (PICCO) were performed in both groups at 1 h, 24 h, 48 h, 72 h, 96 h and 7 d after admission, with data concerning left ventricular global longitudinal strain (GLS), left ventricular ejection fraction (LVEF) and global ejection fraction (GEF), left ventricular systolic force index (dP/dtmx) were obtained, respectively. Hemodynamics and other safety indicators were monitored throughout the whole process. These subjects were followed up to 90 d, with their mortality recorded at Day 28 and Day 90, respectively. Statistical analyses were performed using SPSS version 21.