Evaluation of right ventricular function in idiopathic scoliosis patients by two-dimensional speckle tracking imaging

English Keywords:Two-dimensional speckle tracking imaging  Idiopathic scoliosis  Right ventricular function

English Abstract:

  【Abstract】 Objectives: To evaluate the right ventricular function in patients with idiopathic scoliosis using two-dimensional speckle tracking imaging(STI). Methods: 41 idiopathic scoliosis patients admitted in our hospital from July 2009 to December 2010 and 30 healthy subjects with age matched and normal heart(control group) were enrolled in this series. According to the Cobb′s angle(range, 30°-125°), 41 patients were divided into 3 groups: mild(<45°, n=5), moderate(45°-80°, n=31) and severe(>80°, n=5) group. All of the patients and healthy subjects were checked echocardiography using GE Vivid 7 echo machine.Firstly, the ejection fraction of right ventricle(RVEF) was obtained by modified Simpson′s method. Then, the two-dimensional strain of right ventricle multi-section systolic phase was measured by the STI. All of the parameters were compared among the 3 patient groups and the control group. Cases with tricuspid valve regurgitation(TVR) were chosen in patient group and control group, then through TVR the pulmonary artery systolic pressure(PASP) was calculated, which was compared between the other two patient groups. The lung function parameters such as forced vital capacity(FVC) and forced expiratory volume in first second(FEV1) were also checked, and FVC% and FEV1% were calculated either.And the correlation between the whole right ventricular strain and Cobb′s angle, strain and FVC% were analyzed by linear correlation. Results: There was no statistical difference in RVEF between the patient group and control group(P>0.05). The two-dimensional strain of right ventricular anterior wall apex, anterior septal apex, septal apex, mid posterior septum and base post-septum were lower in severe scoliosis group than control group significantly(P<0.05), while there was no significant difference between mild or mid patient group and control group(P>0.05). And the strain of base posterior septum in severe group were lower than in mild group(P<0.05), while no significant difference in moderate group(P>0.05). TVR was positive in 25 patients and 18 healthy subjects, and there was no statistical difference in PASP between the 2 groups(P>0.05). FVC% and FEV1% in severe group was lower than in mild group(P<0.05), while no difference was noted between moderate and mild group, moderate and severe group(P>0.05). There was negative correlation between whole right ventricular strain and Cobb′s angle(r=-0.93, P<0.05), while the weak correlation between stain and FVC% was noted(r=0.47, P<0.05). Conclusions: Two-dimensional STI can detect the anomalies of right ventricular function in idiopathic scoliosis patients susceptibly, which is a valuable method for evaluating the right ventricular function. Severe idiopathic scoliosis may disturb the motion of right ventricular myocardium then weaken the right ventricular function.