부산대학교 도서관

Background: Left ventricular (LV) dysfunction is a major determinant of late adverse clinical outcome in patients after surgical repair of Tetralogy of Fallot (ToF). Ventricular interaction has been proposed as a cause of LV dysfunction in patients after surgical repair of ToF. However, the influence of right ventricular (RV) dilatation on LV twist and its clinical implications in patients with ToF have not been explored. The aim of this study was to evaluate LV twist in patients after surgical repair of ToF and is relation with RV dilatation by 2D echocardiographic speckle-tracking imaging.Methods and results: Thirty-two asymptomatic patients with ToF (age 28 ± 9 yrs) and 32 healthy controls with normal RV dimensions matched for age and sex were recruited in this study. Using speckle tracking, we analysed the rotation curves at apex and base and calculated the net twist and torsion of the LV. LV twist patterns were determined and defined as follows: pattern 1, completely normal twist; pattern 2, reduced normal twist and pattern 3, no twist. RV volumes of patients with ToF were assessed by cardiac magnetic resonance imaging (n=24). The majority of normal subjects had LV twist pattern 1 (98%), whereas 21 patients with ToF had pattern 2 (66%) and 11 patients with ToF had pattern 3 (34%). This resulted in a significantly decreased LV twist in patients with ToF compared to controls (5,0 ± 1,9° vs 10,8 ± 3,4°, p < 0,001). Figure 1 demonstrated the relation between RV volume and reduced LV twist and no twist in patients with ToF. In patients with no twist, RV volume were significantly increased compared to the patients with reduced LV twist (p < 0,01).In conclusion, the negative impact of RV dilatation on LV function suggests that it relates to influence LV twist in patients after ToF repair.