NPPB and pericardial effusion: In the present study, P-pulmonale, heart rate, and qR in V1 were associated with severe RV dysfunction; heart rate and qR in V1 were significantly associated with 6MWD; heart rate was correlated with NT-proBNP levels; WHO FC, 6MWD, presence of pericardial effusion on echocardiography, NT-proBNP level, heart rate, ST segment depression in V1–V3, and qR pattern in V1 were significantly associated with mortality; while only NT-proBNP was independent predictor of mortality.