What are the clinical manifestations of pediatric pericardial effusion? The symptoms of pericardial effusion in children are commonly shortness of breath and chest pain. Some patients show symptoms of pericardial blockage early in the course of the disease, which in turn will gradually decrease or even disappear as the disease progresses. There is little or no history of acute pericarditis, so it is impossible to determine the exact time of onset of the disease. When the pericardial effusion suddenly and sharply increases, the adaptive expansion of the pericardium, the increase of the effusion underneath, and the manifestation of restrictive pericardial effusion, there is a possibility of pericardial blockage, which should be taken seriously enough.