Chest pain, a pericardial friction rub (audible in about 85% of patients), electrocardiographic changes, and pericardial effusion with cardiac tamponade and paradoxical pulse are cardinal manifestations of many forms of acute pericarditis.
Cardiac tamponade: The accumulation of fluid in the pericardial space in a quantity sufficient to cause serious obstruction to the inflow of blood to the ventricles=> limitation of ventricular filling and reduction of CO.
The three most common causes of tamponade are neoplastic disease, idiopathic pericarditis, and pericardial effusion secondary to renal failure.
The three principal features of tamponade (Beck’s triad) are hypotension, soft or absent heart sounds, and jugular venous distention.
Laboratory Examinations
o Chest radiogram: "water bottle" heart.
o ECG: Low ECG voltage, electrical alternans.
o Echocardiography: The quantity of fluid necessary to produce this critical state may be as small as 200 mL when the fluid develops rapidly or >2000 mL in slowly developing effusions when the pericardium has had the opportunity to stretch and adapt to an increasing volume. But the volume of fluid varies the thickness of the ventricular myocardium and inversely with the thickness of the parietal pericardium.
o CT, MRI.
o Right heart catheterization is also helpful in determining the hemodynamic significance of a pericardial effusion, especially in patients with a subacute or chronic presentation.
Treatment:
 Drainage of the pericardial space via pericardiocentesis or surgical pericardiotomy.
 If pericardial drainage cannot be performed, stabilization with parenteral inotropic support and aggressive administration of IV saline to maintain adequate ventricular filling are indicated.
 Diuretics, nitrates, and any other preload-reducing agents are contraindicated.
 Bed rest and anti-inflammatory, analgesics. Anticoagulants should be avoided.