Echocardiography
Echocardiographic data obtained using the ultrasound device Profound F
75 Premier (Hitachi Ltd, Tokyo, Japan) with a 1-5 MHz sector probe
(UST-52105) were analyzed. Echocardiography was performed by experienced
sonographers (T.M., M.K., and C.S.) Standard 2D resting echocardiography
was conducted in the lateral decubitus position. Conventional
echocardiographic data were collected in accordance using the method
recommended by the American Society of Echocardiography (9) (15) (16).
The modified Simpson’s biplane method was used to calculate LVEF and the
left atrial volume index (LAVI). Transmitral E and A wave peak
velocities were obtained in the apical three-chamber view. Diastolic
mitral annular velocities (e’ and a’) were obtained using Doppler tissue
imaging at the septal side of the mitral annulus from the apical
four-chamber view. Peak velocities in the LV outflow tract (LVOT),
aortic valve, and tricuspid valve were assessed using continuous Doppler
imaging.
Cine loop color images from the apical three-chamber view were acquired
for use in the VFM analysis. The colored area of this movies is set to
include the entire LV area, LV inflow tract, and LVOT during all cardiac
cycles. The Doppler area were optimized in order to achieve the highest
frame rate. The Nyquist limit set for 2D color Doppler imaging was 69.3
cm/s.