A preliminary study on the standard value of left ventricular mechanic dyssynchrony by speckle tracking

Abstract

Abstract Background Speckle tracking imaging automatic functional imaging (AFI) is a new method to measure left ventricular mechanical dyssynchrony. Parameter peak strain dispersion (PSD) is the standard deviation when the long axial strain of 17 segments of the left ventricle (LV) reach there’s peak. There is no unified standard value at present. Li C[1] included 59 healthy women aged 43.08 ± 8.22 years old, whose PSD was 31.44±3.83ms. Ji X[2] included 57 healthy volunteers aged 43.30 ±6.03 years old whose PSD value was 23.8±2.2ms. Some studies referred to the standard range of Yu index and used PSD>32.6ms as an indicator of left ventricular mechanic dyssynchrony. Purpose To investigate the standard value range of PSD and PSD/R-R interval. Methods Healthy volunteers who came to our hospital for physical examination from March 2020 to September 2021 were included, excluding hypertension, diabetes, hyperlipidemia, coronary heart disease and other diseases. According to the 20∼29 years old, 30∼39 years old, 40∼49 years old, 50∼59 years old, 60∼69 years old and 70∼79 years old, 10 males and 10 females were included, respectively. GE Vivid E95 was used to collect echocardiographic images, and the following parameters were measured: ①The general parameters of the heart, such as the diameter of the atrium(LA) and the left ventricle (LV) and the thickness of the left ventricular wall .; ②the values of PSD and PSD/ R-R interval. The normal distribution parameters were represented by mean plus or minus the standard deviation. Analysis of variance and post hoc test (LSDt-test) were used to analyse measured values statistically. Results Values of general echocardiographic data such as BSA, atrial and ventricular diameter, interventricular septal thickness, left ventricular posterior wall thickness, and LV ejection fraction were consistent with the guideline of Recommendations for Cardiac Chamber Quantification by Echocardiography in Adults: An Update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging published in 2015. The range of PSD values for subjects in this study was 43±9ms, and the maximum was 65ms. The range of PSD/R-R was 5±1%, and the maximum was 7%. The values of PSD and PSD/R-R were 36±5ms(27∼45ms) and 4.4±0.76%(3∼6.4%) for 20∼39 years old, 42±5ms(34.9-54ms), 5.0±0.8%(3.5-6.7%) in 40∼59 years; 51±8ms(34∼65ms), 5.8±0.9%(3.9∼7%) in age 60∼79. Conclusions The preliminary study has shown that left ventricular mechanical dyssynchrony is associated with age. The standard value range of PSD is inconsistent in different age groups, and PSD and PSD/R-R values increase with age.PSD values at different agesBar chart of PSD values at different age