Background: The ischemic process in stable Coronary Artery Disease (CAD) causes cardiac remodeling and dysfunction, signaling the progress towards irreversible heart failure. Early identification for the presence of Left ventricular (LV) remodeling and dysfunction is important. Several methods can be used to assess LV dysfunction using echocardiography, including peak Global Longitudinal Strain (GLS) and ejection fraction measurements. Short-term Heart Rate Variability (HRV) and QT interval are considered practical parameters in electrocardiography identifying LV dysfunction. This study aimed to determine the relationship between short-term HRV and QT interval with LV systolic function in stable angina pectoris patients.
Methods: This cross-sectional study was conducted in Prof. Dr. R. D. Kandou Hospital, Manado, from March to September 2021. All study subjects who met the inclusion criteria underwent a clinical history and further examinations, including electrocardiography, laboratory, and echocardiography examinations. The relationship of HRV variables and QT interval with LV systolic function were analyzed using Pearson correlation and linear regression models by SPSS version 21 for Windows.
Results: A total of 33 subjects were included with a mean age of 62.3±8.9 years. Non-parametric correlation analysis between HRV variables and left ventricular systolic function showed no significant correlation. There was a significant correlation between QTc interval by Fridericia and LV peak GLS, but not with ejection fraction (r=0.426; p=0.013). The univariate regression analysis showed a relationship between QTc interval by Bazett and Fridericia with peak GLS (Bazett B=0.036; ?=0.35; R2=0.122; p=0.046; Fridericia B=0.052; ?=0.426; R2=0.181; p=0.013).
Conclusion: There was a weak and moderate positive correlation between the QTc interval by Bazett and Fridericia formula with left ventricular systolic function. There was no statistically significant correlation between the short-term HRV variable and left ventricular systolic function.