Acute Pericarditis and Cardiac Tamponade

Regarding Acute Pericarditis and Cardiac Tamponade answer the following questions.

1. What are the most common causes of acute pericarditis?
2. What is cardiac tamponade?
3. Does acute pericarditis often result in cardiac tamponade?
4. What are the signs and symptoms of pericarditis and tamponade?
5. How is the echocardiogram helpful in the diagnosis of pericarditis or tamponade?
6. What is the treatment for cardiac tamponade?

Answers:

1. What are the most common causes of acute pericarditis?
The most common causes of acute pericarditis are

• idiopathic, 
• viral infection, 
• uremia, 
• myocardial infarction MI),
• trauma, 
• cardiac surgery, and 
• neoplasm.

2. What is cardiac tamponade?
Cardiac tamponade results from accumulation of fluid within the pericardium. As fluid accumulates, intrapericardial pressure increases, limiting filling of the heart and reducing stroke volume. As intrapericardial pressure rises, cardiac filling is increasingly limited. Ultimately, pressures equalize in the left atrium, pulmonary vasculature, right atrium, and superior vena cava (SVC); ventricular filling is progressively impaired and circulatory collapse ensues.

3. Does acute pericarditis often result in cardiac tamponade?
Acute pericarditis results in tamponade only rarely. Tamponade is more common in end-stage renal disease and neoplastic disease despite the frequent absence of an identifiable episode of acute pericarditis in these conditions.

4. What are the signs and symptoms of pericarditis and tamponade?
The most common symptom of acute pericarditis is chest pain. The pain is generally sharp and is worse with cough, deep inspiration, and recumbency.
A pericardial friction rub is the most common finding in acute pericarditis. It often has three components that occur in systole, and early and late diastole when the heart is moving and the pericardial surfaces rub against one another.
Symptoms of tamponade depend on the degree of hemodynamic compromise. The common symptoms of pericardial effusion with tamponade include dyspnea (80%), cough (30%), orthopnea (25%), and chest pain (20%).
The common signs of pericardial effusion with tamponade are jugular venous distension and tachycardia (both nearly 100%), pulsus paradoxus (89%), systolic blood pressure ≤90 mm Hg (52%), and pericardial rub (22%).

5. How is the echocardiogram helpful in the diagnosis of pericarditis or tamponade?
The echocardiogram is the most accurate and easily available tool to detect and quantify pericardial fluid. How ever, it is often not of diagnostic value in acute pericarditis because the absence of pericardial fluid does not exclude the diagnosis of acute pericarditis, especially in idiopathic or viral
pericarditis. In patients with pericarditis due to neoplasm, bacterial infection, trauma, or cardiac surgery, the echocardiogram may provide helpful information about the etiology of the effusion. For example, metastases may be visible on the pericardial surfaces.
The echocardiogram is the most commonly used technique for the diagnosis of cardiac tamponade. Typical findings in addition to the presence of pericardial fluid include right atrial and right ventricular diastolic collapse, exaggerated respiratory changes in tricuspid and mitral valve flow, and
plethora of the inferior vena cava. Because the limitation of cardiac filling is progressive as the effusion increases, findings of tamponade may be detected by echocardiogram before the classically described clinical triad of hypotension, paradoxical pulse, and increased systemic venous pressure.

6. What is the treatment for cardiac tamponade?
Cardiac tamponade requires immediate treatment to relieve the increased end-diastolic pressure and inadequate ventricular filling. The treatment of cardiac tamponade consists of w ithdraw al of fluid from the pericardial space, generally through a needle inserted percutaneously—a procedure called
pericardiocentesis. Pericardiocentesis may be performed using P.echocardiographic guidance to place a needle or a catheter in the intrapericardial space or in the cardiac catheterization laboratory using
fluoroscopic guidance. Intravenous (IV) fluids such as blood or saline may be used, but only as a temporizing measure. Volume administration is useful only in hypovolemic patients. In normovolemic patients, the administration of fluid may exacerbate the intrapericardial pressure.