Value of right ventricular morphology and function on predicting early tachyarrhythmia after surgical rectification of tetralogy of Fallot in infants

Zhang Yaping; Zhu Yaobin; Yang Yao; He Yan; Fan Xiangming; Su Junwu; Liu Yinglong

doi:10.3760/cma.j.issn.1673-4777.2016.02.006

Abstract：Objective To explore the value of right ventricular morphology and function on predicting early tachyarrhythmia (ET) after surgical rectification of tetralogy of Fallot (TOF) in infants.Methods Totally 363 TOF children ＜ 3 years old who underwent surgical rectification of TOF from January 2009 to July 2015 were enrolled.Echocardiography was used to detect the right ventricular ejection fraction (RVEF) and right ventricular outflow tract inner diameter (RVOTID) within 24 h after surgery;electrocardiogram (ECG) and ECG monitoring were performed after surgery.The cases were divided into ET group and non-ET group.Risk stratification was performed for RVEF and RVOTID,Logistic regression analysis was used to evaluate the effects of RVEF and RVOTID on early cardiac tachycardia,taking RVEF≥40％ and RVOTID ≤2 cm/m2 as reference value.The predictive value of RVEF and RVOTID on early postoperative tachycardia after rectification of TOF was evaluated by using receiver operating characteristic (ROC) curve.Results There were 22 cases in ET group (19 cases of early stage ventricular tachycardia,3 cases of early ventricular tachycardia) and 341 cases in non-ET group.The baseline data were not significautly different between groups (P ＞ 0.05).The RVEF in ET group was significantly lower than that in non-ET group [(29 ± 12)％ vs (40 ± 10)％],the RVOTID in ET group was significantly higher than that in non-ET group [(73 ± 19) cm/m2 vs (46 ± 11) cm/m2] (P ＜ 0.05).Pearson linear analysis showed that RVEF was negatively correlated with RVOTID (r =-0.7,P ＜ 0.05).Logistic analysis showed that risk of ET increased as RVEF decreased [＞20％-＜40％:odds ratio (OR) =1.23,95％ confidence interval (CI):0.89-1.48,P=0.61;≤20％:OR=1.81,95％ CI:1.24-2.45,P=0.01] and RVOTID increased [＞2 cm/m2-＜5 cm/m2:OR=1.68,95％CI:1.26-2.08,P=0.03;≥5 cm/m2:OR=2.74,95％CI:1.75-4.05,P＜0.01].ROC showed that the area under curve (AUC) for RVOTID was 0.82 (95％ CI:0.76-0.89,P ＜0.05),the sensitivity and specificity of predicting ET was respectively 0.83 and 0.67,taking 3.8 cm/m2 as cut-off point;the AUC for RVEF was 0.58 (95％ CI:0.47-0.72,P =0.21).Conclusions Decreased RVEF and increased RVOTID are associated with ET after rectification of TOF in infants;RVOTID has higher sensitivity and specificity on predicting ET compared with RVEF.