Abstract 14632: Effect of Obesity on Myocardial Strain Determined by Speckle Tracking Imaging

Abstract

Introduction: Obesity may affect cardiac function, which is hard to detect by traditional echocardiography in the early stages. Speckle tracking imaging (STI) is sensitive to subtle myocardial dysfunction. The aim of this study was to determine the influence of obesity on left ventricular (LV) myocardial function in diet-induced obesity (DIO) mice using two-dimensional (2D) speckle tracking echocardiography (STE). Hypothesis: 2D STE is useful to detect obesity-caused myocardial dysfunction. Methods: Twenty newborn mice were divided into two groups: a DIO group (high-fat diet) and a control group (regular-fat diet). 2D image loops were acquired at the end of each month for 6 months. Global longitudinal strain (GLS) and global circumferential strain (GCS) were analyzed at feeding periods over 3 months and 6 months, and compared between the two groups. Results: The control group gained 64% of its initial weight, while the DIO group gained 82% of its initial weight at the 3 month feeding period; and the two groups gained 88% (control) and 125% (DIO) respectively at 6 months. STE analysis revealed an insignificant decrease in strain values in the DIO mice after 3 months; however, after 6 months, the DIO group demonstrated a significant decrease in strain values (P<0.05) despite normal ejection fractions in both groups. Conclusions: 2D STE is highly feasible to detect the myocardial dysfunction caused by obesity in earlier stage. These strain values appear to be related to the severity of obesity.