[Pathological processes with accumulation of fluid in the pericardial sac].

Fluid in the pericardial sac may accumulate due to transudate, inflammatory process in the pericardium, shunting of blood from the ventricles or large vessels into the pericardial cavity. The presence and amount of fluid is best evaluated by using echocardiography. Pathological fluid in the pericardial sac does not cause major hemodynamic disorders until the intrapericardial pressure is normal. This condition is treated mainly pharmacologically. An increase in the intrapericardial pressure and its equalization with the right and left ventricular diastolic pressure lead to cardiac tamponade which is characterized by decreased cardiac output and increased central venous pressure. Severe tamponade may result in cardiac arrest due to electromechanical dissociation. In lighter cases one can observe tachycardia, tachypnoe, fall in arterial blood pressure, rise in central venous pressure, paradoxical pulse. The patients complain of dyspnea and chest pain. Cardiac tamponade may be due to all causes of fluid accumulation in the pericardial sac, but most frequently it results from perforation or rupture of the left ventricle or aorta, and severe idiopathic, viral, uremic or neoplastic pericarditis. Therapy in cardiac tamponade consists of removal of the pericardial fluid by means of pericardiocentesis, pericardiotomy or pericardiectomy.