Effect of Thoracic Epidural Anesthesia on Left Ventricular Functions: a Strain Echocardiography Study

HR, MAP, SBP, and DBP will be recorded at baseline and 15 minutes after ESP block. Cardiac output (CO) will be calculated using echocardiographic data on stroke volume (SV) (measured from the LV outflow tract) and multiplied by HR. Two transthoracic 2D echocardiographic examinations will be performed immediately before and 15 minutes after TEA. The examinations include apical four-, two-, and three-chamber projections, mitral and aortic Doppler flow velocities. Standard measurements of left ventricular systolic function include left ventricular volumes (indexed to body surface area, BSA), left ventricular ejection fraction (LVEF) according to the modified Simpson rule, time and velocity integral in the left ventricular outflow tract (TVI-LVOT), and stroke volume (SV) (= π x LVOT radius2 x TVI-LVOT). Stroke volume index (SVI) will be calculated as SV/BSA. Mitral and aortic Doppler flow profiles, left ventricular isovolumetric relaxation time, maximum flow velocity will be recorded for m