Left ventricular systolic function in children with repaired tetralogy of Fallot by pressure-strain loops / 中华超声影像学杂志

ABSTRACT

Objective:To quantify the left ventricular myocardial work in patients with repaired tetralogy of Fallot (TOF), and to evaluate the changes in left ventricular systolic function after TOF repair by pressure-strain loops (PSL).Methods:Seventy-six cases of children after TOF complete surgery in Shenzhen Children′s Hospital from September 2015 to September 2021 were analyzed retrospectively. There were 41 cases in the ≤4-year group and 35 cases in the >4-year group. Seventy-six healthy children with matched body surface area in the same period were selected as the control group. All subjects underwent complete echocardiography and quantitative analysis of left ventricular myocardial work, including global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). Compared with the normal control group, the changes of left ventricular myocardial work after TOF repair were analyzed. For patients with complete echocardiographic data before and after surgery, the correlation between postoperative left ventricular myocardial work and preoperative degree of right ventricular outflow tract (RVOT) obstruction was analyzed.Results:①In the ≤4-year group, compared with control subjects, GLS, GWI, GCW, GWE decreased, and GWW increased in patients with repaired TOF. All the differences were statistically significant [(-20.00±1.52)% vs (-21.59±1.73)%, (1 349.37±133.63)mmHg% vs (1 553.51±246.09)mmHg%, (1 589.39±167.85)mmHg% vs (1 749.12±249.45)mmHg%, 94.0%(94.0%, 95.0%) vs 96.0%(95.0%, 97.0%), (78.80±20.53)mmHg% vs (62.27±21.44)mmHg%; all P<0.05]. ②In >4-year group, compared with the control group, GLS, GWI, GWE decreased, and GWW increased in patients with repaired TOF. All the differences were statistically significant [(-19.89±1.66)% vs (-21.31±1.60)%, (1 486.09±172.42)mmHg% vs (1 713.14±227.05)mmHg%, 96.0%(94.0%, 96.0%) vs 97.0%(96.0%, 97.0%), 75.00(65.00, 95.00)mmHg% vs 55.00(42.00, 71.00)mmHg%; all P<0.05]. ③GWW was negatively correlated with preoperative RVOT diameter and RVOT-Z score( r=-0.422, -0.433; both P<0.05). GWE was positively associated with preoperative RVOT diameter and RVOT-Z score( r=0.441, 0.540; both P<0.05). ④GLS, GWI, GCW, GWW, GWE had good repeatability within and between observers.All the differences were not statistically significant (all P>0.05). Conclusions:Left ventricular systolic function in patients with repaired TOF is lower than that in healthy children of the same age by echocardiography PSL, although traditional indicators are still within the normal range. Patients with more severe RVOT obstruction before surgery have worse left ventricular systolic function after operation. Quantification of left ventricular myocardial work by echocardiography PSL is helpful for long-term follow-up of children after TOF repair.