Evaluation of QRS, QTc, and JTc intervals in Congenital Heart Disease with Pulmonary Hypertension

Background Pulmonary hypertension (PH) in congenital heart disease affects the patient's prognosis. Prolonged QRS and QTc intervals in ECG may intensify life-threatening dysrhythmia in patients. We aimed to investigate the correlation between QRS, QTc, and JTc intervals prolongation in ECG with PH in Congenital Heart Disease (CHD) patients. Materials and Methods: This cross-sectional study was performed in the pediatric cardiology clinic of Be'sat Hospital in Hamadan, Iran, in 2016-2018. Patients with CHD and PH were compared with CHD patients without any evidence of PH as the control group. Afterward, QRS, QTc, and JTc intervals in ECG, RV MPI, and TAPSE echocardiography were compared between the case group (PH group) and the control group. We also compared the ECG and echocardiographic results between mild and severe PH patients in the case group. Results: In this study, 40 patients in the case group (with CHD and PH) were compared to 40 patients in the control group (only CHD without PH). There was a significant difference in QRS (p=0.005) and QTc (p=0.036) intervals between the two groups, but no significant difference in the JTc interval was observed. Of 40 patients with PH, 19 were in the mild PH subgroup, and 21 were in severe PH subgroup, in which 9 patients had irreversible PH or Eisenmenger syndrome (ES). QTc (p<0.001) and QRS (p=0.018) intervals in the severe PH subgroup with ES were significantly different from the mild PH subgroup, but the JTc interval was not significantly different. Conclusion Despite longer QRS and QTc intervals in the PH group of CHD, JTc interval did not show a significant prolongation.