2.2 Conventional Echocardiography
Blood pressure, heart rate, and BSA measurements of all the individuals
were recorded before the examination. Echocardiography was performed by
an experienced cardiologist during the recovery period post-HD. Subjects
were in the left lateral decubitus position, aspirated calmly, and
connected with synchronous electrocardiogram. The measurements were
carried out using the echocardiography machine (Vivid E95; GE
Healthcare, Horten, Norway) and a 5S (3.5-5Mhz) probe.
Images included 2D, M-mode, pulsed-, and continuous-wave Doppler in
addition to Tissue Doppler Imaging (TDI) were obtained from the standard
parasternal and apical positions according to the guidelines of the
American Society of Echocardiography (ASE). Zoomed LA were obtained in
4-and 2-chamber views at high frame rates (60-80 frames/sec), and three
consecutive cardiac cycles were stored. LAV (maximum[max],
maximum[min]), 2D LAEF were measured by biplane Simpson’s method. LA
diameter, including antero-posterior diameter (LAD1), medial-later
diameter (LAD2), and superior-inferior diameter (LAD3) were measured
from left ventricular long axis and apical 4 chamber. Left ventricle end
diastolic dimensions (LVEDd), interventricular septum diastolic
thickness (IVST), posterior wall diastolic thickness (PWT) and LVEF were
measured by M-mode method.
Left ventricle diastolic function was assessed: Peak E and A velocity
were measured by pulsed-wave doppler at the mitral leaflet tips in the
apical 4-chamber view, and the E/A ratio was calculated. TDI velocities
early diastole (e’) were recorded with the sample volume placed on the
septal and lateral mitral annulus, and E/e’ was calculated. Pulmonary
capillary wedge pressure (ePCWP) was calculated according to the
following formula: ePCWP = 1.25(E/E’) + 1.9[5]. Pulmonary artery
systolic pressure(PASP) was estimated with the Bernoulli equation
formula: 4xTRv2 + RAP, where v is the peak tricuspid regurgitation
velocity, measured by continuous-wave Doppler, added to the estimated
right atrium pressure, which was calculated based on inferior vena cava
(IVC) diameter and the extent of its collapse during inspiration.
[6]