Acute Pericarditis – Overview, Causes, and Signs

Overview:

• The pericardium is a double-walled sac composed of the visceral and parietal pericardium layers surrounding the heart.
• Normally, the pericardial space contains a small amount of serous fluid (a few millimeters), which allows the heart to move freely without friction.

Definition:

• Acute pericarditis is the inflammation of the pericardial sac surrounding the heart.
• It is usually a secondary condition, caused by an underlying problem or injury, not just spontaneous.

Pathophysiology:

• Inflammation causes the visceral and parietal layers of the pericardium to rub against each other.
• This friction can produce a sound called a friction rub, heard with a stethoscope.
• The inflammation is associated with exudate—fluid, fibrin, or blood—building up in the pericardial cavity.

Causes:

• Irritation or injury:
  • Surgery near the heart.
  • Myocardial infarction (heart attack) especially if it affects the visceral pericardium (epicardium).
  • Infections: Viral (most common), bacterial, or fungal infections.
    • Can be caused by infections (e.g., tuberculosis)
  • Trauma to the chest or heart.
  • Cancer, radiation therapy
  • Autoimmune diseases (like systemic lupus erythematosus).
  • Other causes: Radiation therapy, malignancies, or metabolic conditions.

• • • Inflammation: Irritation or injury will cause inflammation
    • Chronic pericarditis: Leads to fibrous scar tissue formation and adhesions between the visceral and parietal pericardial membranes.

Possible Complications of Pericarditis:

1. Pericardial Effusion:

• Accumulation of fluid in the pericardial cavity due to inflammation, infection, or trauma.
• Types of fluid:
  • Serous fluid: Watery, non-infectious.
  • Pus: Bacterial or viral infection.
  • Blood: Due to hemorrhage or trauma.

2.  Cardiac Tamponade:

• Excess fluid compresses the heart.
• • The heart cannot expand fully or pump effectively.
• Pathophysiology:
  • Impaired ventricular filling → decreased stroke volume and cardiac output.
  • Blood backs up into pulmonary circulation (right-sided failure) and systemic circulation (left-sided failure).
• Signs:
  • Distended jugular veins in neck.
  • Friction rub on auscultation due to membranes rubbing.
  • Hypotension and pulsus paradoxus (drop in systolic BP >10 mm Hg during inspiration).

Signs and Symptoms:

• Chest pain: Sharp, retinal, worsened by lying down or deep breathing.
• Friction rub: Heard during auscultation, indicates inflamed pericardial layers rubbing together.
• Related symptoms: Fever, fatigue, malaise.

 Diagnostic & Therapeutic Procedures:

• Pericardiocentesis:
  • Emergency drainage of excess fluid.
  • Fluid analyzed to determine the cause (infection, cancer, hemorrhage).

• • • A long needle (8 inches, 16 or 18 gauge) inserted into the xiphoid region at a 45° angle toward the left shoulder.
    • Needle advanced carefully into the pericardial space.
    • Fluid (blood, pus, or serous fluid) is withdrawn.
  • Purpose:
    • Rapidly relieves pressure on the heart.
    • Restores normal heart filling and pumping.

• • Importance of rapid intervention of Cardiac Tamponade:
    • Necessary to prevent cardiac arrest and organ failure due to severely reduced cardiac output.

• Address primary cause:
  • Treat infections (antibiotics).
  • Manage cancer or remove fibrous tissue if possible.

• Monitor for signs of cardiac tamponade.
• Early intervention: Percutaneous drainage to prevent hemodynamic collapse.

Long-term & Chronic Effects:

• Fibrous adhesions can develop, restricting heart movement.
• Chronic pericarditis can lead to constrictive pericarditis, impairing stroke volume and cardiac output.
• Symptoms include pain, dyspnea, fatigue, weakness, edema, and ascites.

Summary:

Acute pericarditis is an inflammatory condition with characteristic chest pain and a rubbing sound. It’s usually caused by secondary factors such as heart attack, infection, or trauma.

Pericarditis can progress to pericardial effusion and potentially cardiac tamponade, a life-threatening condition requiring immediate drainage. Causes include infections, cancer, trauma, or inflammation. Proper diagnosis, prompt drainage, and addressing the primary causes are essential for good outcomes and preventing shock or organ failure.

Cardiac tamponade occurs when fluid or blood builds up in the pericardial sac, compressing the heart and impairing its function. It is an emergency that requires immediate pericardiocentesis—a needle aspiration procedure—to remove the excess fluid and restore normal heart function.