Effect of Left Erector Spinae Plane Block on Left Ventricular Functions

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. Changes in LV systolic function will be assessed with three parameters: fractional shortening (FS), ejection fraction (EF) using the Simpson method and S' wave of tissue Doppler imaging (TDI) of the mitral annulus (average of values at the medial and lateral annulus). LV diastolic function will be assessed with three parameters and interpreted according to the European Association of Cardiovascular Imaging guidelines. Pulsed wave (PW) Doppler of trans-mitral flow will be used to obtain the ratio between early (e) and late (atrial, a) waves. A PW Doppler between the LV outflow tract and the mitral valve will be performed to estimate the iso-volumetric relaxation time IVRT. TDI will be used to investigate myocardial relaxation at the mitral annular level (ear