4 Dimensional X-Strain Speckle Tracking Echocardiography: Assessment of Normal Values of Left Ventricular Rotation and Twist, in Healthy Indian Adults during Covid-19 Pandemic

Cardiac MRI and 2Dimensional speckle Tracking Echocardiography (2D STE) are the most sought-after methods to evaluate LV twist mechanics. LV rotational deformation resembles the wringing of a towel, and this deformation is referred as LV twist (LVT), and the subsequent recoil in diastole is known as LV untwist (LVUT). 2D/3D/4D twist mechanics assessment by STE is inherently associated with limitations. Recently introduced 4D XStrain STE has been used for evaluation of strain parameters because of better appraisal of contractile properties of LV, to analyse complex multi-dimensional LV rotational mechanics. This novel technology is a reliable, affordable, and simple tool for quantification of regional myocardial functions, particularly LV strain and rotation parameters. To evaluate and establish the normal values of LV rotation and twist by 4D XStrain STE in healthy Indian adults during the Covid-19 pandemic was the aim of the current study. 46 subjects were enrolled (34 males & 12 females). LA size, LV mass, CO, LVEDV and mitral E/A ratio were significantly greater in males (p<0.01) even though EF was higher in females (p<0.01). GLS, GCS, and GRS were increased in males (p<0.01). Peak basal rotation, peak twist, peak twist rate, and peak untwist rate were also greater in males (p<0.01), nonetheless, peak apical rotation and papillary muscle rotational velocity were greater in females (p<0.01). However, MV rotational velocity was increased in males (p<0.01). This is the first research publication of normal values of LV rotation and twists in healthy Indian adults by 4D XStrain STE.