Myocardial deformation in rats following transverse aortic constriction measured by speckle tracking echocardiography. Abstract: Background: Currently, 2D echocardiography (2DE) is the first line diagnostic imaging tool for detection of cardiac hypertrophy and heart failure (HF). However, early detection of cardiac hypertrophy and HF is difficult with 2DE conventional parameters. We aimed to perform a longitudinal study of the strain deformation parameters using speckle tracking echocardiography (STE) following TAC surgery in rats and to determine STE is more sensitive to the early changes of LVH induced HF when compared to conventional 2DE. Methods: Baseline 2DE was performed on 8-9 weeks old male Fisher-344 rats with the average weight of 234.10 ± 9.12g. Subsequently, randomised transverse aortic constriction (TAC) surgery (n= 5) or sham surgery (n=5) surgery was performed. and 2DE was repeated monthly for up to 8 months. Conventional parameters and STE based strain parameters were analysed, and repeated analysis of all strain measurements was performed on 3 randomly selected rats at 1 month apart to assess reproducibility. Results: LV mass, anterior and posterior wall thickness (Anted and PWTed) of TACoperated rats were found significantly increased monthly, over the time course of 8 months. Significant changes to left ventricular internal diameter, ejection fraction and fractional shortening were also observed to occur no earlier than 6 months. In contrast, a significant reduction in epicardial global circumferential strain (GCS) was already observed in the TAC-operated rats 2 months after TAC surgery. This was followed by a reduction in endocardial global radial strain (GRS) at 4 month, while epicardial global longitudinal strain (GLS) and endocardial GCS were significantly reduced from 5 months in the TAC-operated rats. Conclusion: STE based strain measurement is a promising surrogate alternative that detects LV systolic dysfunction during the disease progression of pressure overloadinduced heart failure earlier than 2DE. Project type: Analysis of existing data Imaging keywords: Ultrasound, 2D Echocardiography (2DE) Ultrasound, Speckle Tracking Echocardiography (STE) Application / disease keywords: Cardiac hypertrophy Heart failure Preclinical imaging Supervisor(s): Dr Maurits Jansen Prof Carmel Moran Programme: Imaging MSc Year: 17-18 This article was published on 2024-08-22
