Cardiac diameters and left ventricular function
By two-dimensional echocardiography, left ventricular end-diastolic dimension (LVEDD) was measured from the parasternal long-axis view, while the right atrial diameter (RAD) and right ventricular diameter (RVD) were measured from the apical four-chamber view. The sampling volume was placed above the aortic valve orifice to obtain the aortic valve blood flow spectrum and measure the aortic valve velocity (AV) from the apical five-chamber view. A modified Simpson’s method was used to measure left ventricular end-diastolic volume (EDV) and end-systolic volume (ESV). Left ventricular ejection fraction(LVEF) was calculated as followed: LVEF=(EDV-ESV)/EDV.