摘要：Background Pulmonary hypertension (PH) in congenital heart disease (CHD) affects the patient prognosis. QRS and QTC intervals prolongation in ECG may exaggerate life-threatening dysrhythmia in these patients. We aimed to investigate the correlation between QRS, QTC and JTC intervals prolongation in ECG with PH in CHD children. Materials and Methods In a cross-sectional study that was performed in pediatric cardiology clinic of Besat hospital (Hamadan, Iran), during 2016-2018, patients with CHD and PH as case group (n=40) were compared to simple CHD patients without any evidence of PH as control group (n=40). Based on Pulmonary Artery (PA) to systemic pressure ratio, lower than 1/2 was considered as mild PH and equal and more than 1/2 was considered severe PH; then QRS, QTC, JTC intervals in ECG and RVMPI, TAPSE in echocardiography were compared between case (PH group), and control groups. We also compared these ECG and echocardiographic findings between mild and severe PH group. Results There was significant difference in QRS (p=0.005), and QTC (p=0.036) intervals between two groups, but there was not any significant difference between JTC interval between two groups (p=0.714). Of 40 patients with PH, 19 subjects were in the mild PH group and 21 subjects were in severe PH group, in which nine patients had irreversible PH or Eisenmenger syndrome. QTC (p
