Assessment of longitudinal systolic ventricular function in children with single ventricle using velocity vector imaging

Objective To investigate the longitudinal systolic ventricular function of children with single ventricle, and to appraise the feasibility and clinical value of velocity vector imaging (VVI) on assessing it. Methods The study group consisted of 30 patients with functional single ventricle. The control group consisted of 30 age- and gender-matched normal children. Using Sequoia C512 echocardiography machine,the peak velocity(V),peak displacement(D) ,strain(S) ,and strain rate(SR) were measured. Results Basel and median velocities,as well as basel and median displacements of rudimentary chamber side(RCS), were lower than those of septum[Basel velocity (1. 93 ± 0. 71)cm/s vs (3. 53 ± 1. 07)cm/s;Median velocity (1.19±0. 57)cm/s vs (2. 03 ± 0. 90) cm/s; Basel displacement (2. 53 ± 1.65) mm vs (6.21 ± 2. 12)mm;Median displacement(1. 26 ± 1. 06)mm vs (3. 21 ± 1.37)mm]. The values of strain of all the six segments of single ventricle were significantly lower than Corresponding segments of the control group [ basel nonrudimentary chamber side(NRCS) ( - 16. 17 ± 4. 37) % vs ( - 19. 66 ± 3. 47) % ; Median NRCS ( - 15. 23 +4.36)% vs (-19.64± 4. 75)%; Apical NRCS (-13.84 ± 5.79)% vs ( - 16. 7 ± 4. 15)%; Basel RCS(-10. 54±5.35)% vs (-19.49±3. 74)%;Median RCS ( - 10. 16 ± 5. 26)% vs ( -20. 83 ± 3. 82)% ;Apical RCS ( - 10. 97 ± 5. 22) % vs C - 18. 11 ± 4.43) %]. Aside from basel strain rates of NRCS, strain rates of all the other five segments of single ventricle were significantly lower than Corresponding segments of the control group [Median NRCS ( - 1. 21 ± 0. 42)s-1 vs (- 1.49 ± 0. 24)s-1 ;Apical NRCS ( - 1.10 ±0.41)s-1 vs (-1.47 ± 0.24)s-1;Basel RCS ( - 1.07 ± 0. 35) s-1 vs (- 1. 49 ± 0. 22) s-1; Median RCS (-0.97± 0.34)s-1 vs ( -1.48 ± 0. 20)s-1 (Apical RCS ( - 0. 93 ± 0. 39)s-1 vs ( - 1. 48 ± 0. 22)s-1]. Conclusions Longitudinal systolic ventricular function is impaired in children with functionally single ventricle. VVI can be used to asses ventricular systolic performance in children with functionally single ventricular. Key words: Echocardiography; Single ventricle; Ventricular function; Velocity vector imaging