Echocardiography

Heart function assessment by Vivid E9 Color Doppler ultrasound system equipped with a 10.0-MHz 9L-D transducer (GE Inc., Vivid E9 system, Wingmed, Milwaukee, USA) was performed prior to and 4, 8 weeks after the surgery, as previously reported (11). Left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic diameter (LVEDD), and left ventricular ejection fraction (LVEF) were directly measured via the long axial section of the left ventricular and averaged from 3 consecutive cardiac cycles, while fractional shortening (FS) was calculated by the equation as follows: FS = [(LVEDD – LVESD)/LVEDD] × 100%. The evaluation was conducted by an independent experimenter in an observer-blinded way.