Pericardial effusion can result in reduced pulse pressure differences between systolic and diastolic pressures. This occurs because pericardial effusion can compromise the heart's pumping function, leading to decreased myocardial contractility, which in turn may lead to excessive vascular pressure and a decrease in pulse pressure. This is a pathological change caused by pericardial effusion. Currently, in treatment, medication can be chosen to improve patient's cardiac function and thereby increase cardiac output. It is also important to actively treat the pericardial effusion, which may involve pericardiocentesis to drain the fluid and check pressures, as this can also alleviate reduced pulse pressure issues.