ECG Markers of Hemodynamic Improvement in Patients with Pulmonary Hypertension

Several diagnostic tests have been recommended for risk assessment in pulmonary hypertension (PH), but the role of electrocardiography (ECG) in monitoring of PH patients has not been yet established. Therefore the aim of the study was to evaluate which ECG patterns characteristic for pulmonary hypertension can predict hemodynamic improvement in patients treated with targeted therapies.

Consecutive patients with pulmonary arterial hypertension (PAH) or chronic thromboembolic pulmonary hypertension (CTEPH) were eligible to be included if they had had performed two consecutive right heart catheterization (RHC) procedures before and after starting of targeted therapies. Patients were followed up from June 2009 to July 2017. ECG patterns of right ventricular hypertrophy according to American College of Cardiology Foundation were assessed.

We enrolled 80 patients with PAH and 11 patients with inoperable CTEPH. The follow-up RHC was performed within 12.6 ± 10.0 months after starting therapy. Based on median change of pulmonary vascular resistance, we divided our patients into two subgroups: with and without significant hemodynamic improvement. R, max⁡R + max⁡S_I,aVL - S, and P_II improved along with the improvement of hemodynamic parameters including PVR. They predicted hemodynamic improvement with similarly good accuracy as shown in ROC analysis: R (AUC: 0.75; 95% CI: 0.63-0.84), P_II (AUC: 0.67, 95% CI: 0.56-0.77), and max⁡R + max⁡S_I,aVL - S (0.73; 95% CI: 0.63-0.82). In Cox regression only change in R remained significant mortality predictor (HR: 1.12, 95% CI: 1.01-1.24).

Electrocardiogram may be useful in predicting hemodynamic effects of targeted therapy in precapillary pulmonary hypertension. Decrease of R, max⁡R + max⁡S_I,aVL - S, and P_II corresponds with hemodynamic improvement after treatment. Of these changes a decrease of R wave amplitude in V₁ is associated with better survival.