Correlation of QRS/T angle with clinical, echocardiographic, and hemodynamic variables in chronic thromboembolic pulmonary hypertension patients

Objectives: In this study, we aimed to examine the relationships between frontal QRS-T (fQRS-T) angle prognostic risk factors outlined in the current pulmonary hypertension (PH) guidelines and to demonstrate whether the fQRS-T could detect patients with unfavorable echocardiographic and hemodynamic data. Patients and methods: Between July 2009 and February 2023, a total of 33 patients (8 males, 25 females; median age: 61 years; range, 55 to 70 years) with chronic thromboembolic pulmonary hypertension (CTEPH) who underwent electrocardiographic (ECG) examination were retrospectively analyzed. The fQRS-T angle was calculated from surface ECGs. Functional class, 6-min walk distance, and brain natriuretic peptide values were recorded. Two-dimensional echocardiographic data including comprehensive right ventricular (RV) functions, right atrial area (RAA), tricuspid annular systolic plane excursion (TAPSE), systolic pulmonary artery pressure (sPAP), and TAPSE/sPAP ratio were noted. Among invasive hemodynamic variables, sPAP, mean PAP (mPAP), pulmonary vascular resistance (PVR), and cardiac index (CI) were obtained. The correlations between clinical, echocardiographic, and hemodynamic variables were analyzed. Results: There was no significant correlation between clinical variables and fQRS-T angle. The TAPSE and TAPSE/sPAP ratio were negatively correlated with fQRS/T angle (r=-0.37, p=0.02, r=-0.35, and p=0.03, respectively), whereas RV Tei index and RAA were positively correlated with the fQRS-T angle (r=0.53, p=0.014, r=0.47, and p=0.007, respectively). The hemodynamic data including sPAP, mPAP, and PVR were positively correlated with the fQRS-T angle (r=0.32, p=0.048, r=0.34, p=0.034, r=0.35, and p=0.02, respectively) and CI was negatively correlated with the fQRS-T angle (r=-0.30, p=0.048). Conclusion: Our study results suggest that the fQRS/T angle is correlated with poor prognostic echocardiographic and hemodynamic variables in CTEPH patients.