ECG patterns to predict pulmonary arterial hypertension in patients with severe tricuspid regurgitation

Introduction: Echocardiographic evaluation of tricuspid regurgitation (TR) velocity is a key measure in screening for pulmonary hypertension. Based on its value and additional features of right ventricle overload patients are classified into low, intermediate or high probability of pulmonary hypertension which transfers into decisions of further invasive evaluation. However, in the presence of severe TR echocardiography underestimates pulmonary artery pressure and therefore pulmonary hypertension may be overlooked in some patients. Accordingly, in the present study we aimed to assess the role of electrocardiography in predicting the presence of pulmonary arterial hypertension (PAH) in patients with severe TR. Results: We analysed 83 consecutive patients with severe TR who were diagnosed in our centre between February 2008 and 2021 and who underwent right heart catheterization. Of them 58 had PAH while 25 had isolated TR (iTR). We found that the following ECG criteria supported the diagnosis of PAH as opposed to the diagnosis of iTR: R: SV1 > 1.0, max RV1 or 2 + max S I or aVL -SV1 > 6 mm, SI/RI > 1 in I. For these parameters using ROC analysis we found that the optimal thresholds suggesting the presence of pulmonary hypertension were: R:SV1 > 1.5 (AUC = 0.74, p = 0.0004, sensitivity 57.1%,specificity of 85%), max RV1 or 2 + max S I or aVL - SV1 > 3 mm (AUC = 0.76, p < 0.0001, sensitivity 91.4%, specificity of 60%) and for SI:RI > 0.71 (AUC = 0.79, p < 0.0001, sensitivity 82.5%,specificity of 70.8%). Presence of atrial fibrillation predicted iTR with 76% sensitivity and 81% specificity. Conclusions: ECG analysis can improve the diagnostic process for patients with severe TR. The presence of atrial fibrillation facilitates the diagnosis of isolated tricuspid regurgitation (iTR), while increased values of R:SV1, R:SI, and increased max RV1 or 2 + max SI or aVL - SV1 favor the diagnosis of TR secondary to PAH.