The Relationship between Electrocardiographic Changes and Prognostic Factors in Severely Symptomatic Pulmonary Hypertension

Background: The prognostic role of the electrocardiogram (ECG) in PH is not fully known. We aimed to evaluate ECG abnormalities in severe PH, the association of ECG patterns with known prognostic factors and to determine whether ECG abnormalities were associated with decreased survival in patients with severe PH. Materials and Methods: Fifty-two patients with severe PH were included. Clinical assessment included basic demographics, complete physical examination, determination of WHO FC, measurement of N-terminal pro-BNP, 12-lead electrocardiography, transthoracic echocardiography, right heart catheterization (RHC) and six minute walk test (6MWT). Results: Heart rate was correlated with NT-proBNP (r=0.54; p-value: 0.0001) and was higher in patients with severe RV dysfunction (93±12 vs. 83±4 bpm in moderate RV dysfunction). P-pulmonale was present in 51.9% of the patients and was significantly associated with severe RV dysfunction. qR in V1 (48.1%) was significantly associated with 6MWT and severe RV dysfunction. Overall, 10 patients died. Based on Kaplan-Meier results, median survival time was 38 months and estimated survival at 1 year, 3 years, and 5 years was 88%, 80% and 71 % respectively. In Cox regression analysis WHO FC, 6MWT, pericardial effusion, NT-pro BNP, heart rate, ST depression in V1 to V3, and presence of qR in V1 were predictors of mortality. After controlling for covariates, only NTproBNP was independently associated with decreased survival. Conclusion: ECG changes including P-pulmonale, qR pattern in V1, and heart rate indicative of right ventricular dysfunction are associated with prognostic factors in severe PH and may be a useful tool in the follow-up.