pericarditis notes

Pericardial Disease / Pericarditis

Etiology

  • Idiopathic: Unknown cause.
  • Infectious:
    • Viral infections: include echovirus, coxsackievirus, adenovirus, cytomegalovirus, hepatitis B, infectious mononucleosis, HIV/AIDS.
    • Bacterial infections: Include pneumococcus, staphylococcus, streptococcus, mycoplasma, Lyme disease, hemophilus influenzae.
    • Mycobacterial infections: Primarily caused by Mycobacterium tuberculosis.
    • Fungal infections: Include histoplasmosis and coccidiomycosis.
    • Protozoal infections.
  • Immune-inflammatory causes:
    • Connective tissue diseases such as systemic lupus erythematosus, rheumatoid arthritis, scleroderma, and mixed connective tissue disease.
    • Arteritis: Conditions like polyarteritis nodosa and temporal arteritis.
    • Early post-myocardial infarction: Can lead to pericarditis early in recovery.
    • Late post-myocardial infarction (Dressler syndrome), late post-cardiotomy/thoracotomy, and late post-trauma.
    • Drug-induced: Medications like procainamide, hydralazine, and cyclosporine are known to cause pericarditis.
  • Neoplastic diseases:
    • Primary tumors: Such as mesothelioma, fibrosarcoma, and lipoma.
    • Secondary tumors: From breast and lung carcinoma, lymphomas, and leukemias.
  • Radiation-induced pericarditis: With 2 to 31% developing constriction post-radiation.
  • Early post-cardiac surgery: Can result in pericardial disease.
  • Device and procedure-related: Associated with coronary angioplasty, implantable defibrillators, and pacemakers.
  • Trauma: Both blunt and penetrating trauma, including post-cardiopulmonary resuscitation effects.
  • Congenital: Issues like congenital cysts or absence of the pericardium.
  • Miscellaneous: Conditions like chronic renal failure, hypothyroidism, amyloidosis, aortic dissection, heart failure, pregnancy, severe pulmonary hypertension, and Trisomy 21 (Down syndrome).

History

  • History and symptoms depend on the underlying etiology:
    • Positional chest pain: The primary symptom characterized as:
    • Precordial (located in the front of the chest)
    • Sharp and severe
    • Increases with inspiration, coughing, or lying down
    • Decreases or improves with sitting upright or leaning forward.
    • Dyspnea: May indicate cardiac tamponade or constrictive pericarditis.
    • Cough: May be present.
    • Fever, sweats, chills: Systemic symptoms that may accompany infection.
    • Tachypnea: Rapid breathing indicative of respiratory distress.
    • Palpitations: Due to atrial arrhythmias.

Physical Examination

  • Clinical signs:
    • A quiet, hypodynamic heart with cardiomegaly suggests the presence of pericardial effusion.

Complications

  • Cardiac tamponade: A severe complication where fluid accumulation compresses the heart.
  • Chronic pericarditis may lead to constrictive pericarditis.

Cardiac Auscultation

  • Pericardial friction rub: A cardinal physical sign of pericarditis; may require exercise or repeated auscultation with postural changes to elicit.
  • Distant heart sounds: Suggests pericardial effusion.
  • Ewart's sign: Indicates large effusion.

Laboratory Findings

  • Elevated white blood count: Indicates possible infection or inflammation.
  • Elevated cardiac enzymes: e.g., troponin, suggest possible myocardial injury.
  • Elevated C-reactive protein: Indicates inflammation (confirmatory finding).
  • Elevated erythrocyte sedimentation rate: Non-specific indicator of inflammation.

Electrocardiogram (ECG) Findings

  • Elevated ST segments: Throughout the ECG with upright T waves within the first hours to days (a classic finding).
  • PR segment depression: Common finding accompanying pericarditis.
  • Sinus tachycardia: Increased heart rate may be seen.
  • Reduction in QRS voltage: Notable throughout the ECG.
  • Supraventricular arrhythmias: Occasional finding.
  • Electrical alternans: Suggests the presence of a large effusion.

Imaging Studies

  • Chest X-ray/CMR/CT Findings:
    • Cardiomegaly with clear lungs is suggestive of pericardial effusion.
    • Noncalcified pericardial thickening.
    • Enhancement of the thickened visceral and parietal surfaces of the pericardial sac with contrast.
    • CT attenuation values of pericardial effusion can help distinguish between exudative and transudative fluids.
  • Cardiac MRI:
    • Enhancement of thickened pericardium on T1-weighted SE or LGE images confirms active inflammation (94 to 100% sensitive).
    • Significant signal in pericardial tissue on T2W images correlates with edema, neovascularization, and/or granulation tissue.
    • High T1W signal intensity on SE images may suggest exudative effusions.
    • Thickened pericardium without enhancement indicates chronic fibrotic pericarditis.
    • Dynamic tagging loss indicates adhesions between the visceral and parietal pericardium.

Cardiac Catheterization

  • Limited role in diagnosis.
  • Increased and equalized diastolic intracardiac pressures with reduced stroke volume suggests cardiac tamponade.
  • Square root sign: May indicate constrictive pericarditis.

Medical Treatment

  • Management focuses on treating the underlying etiology, such as:
    • Exercise restriction: To minimize cardiac workload.
    • Analgesia: Medications such as aspirin, indomethacin, and ibuprofen.
    • Steroid therapy: Prednisone may be employed.
    • Immunosuppression therapy: For recurrent pericarditis, incorporates agents like colchicine and azathioprine.

Surgical Treatment

  • Pericardiocentesis: Indicated to identify the etiology or relieve cardiac tamponade.
  • Pericardial window: Allows for drainage of fluid and may include pericardial biopsy.
  • Pericardiectomy: Surgical removal of the pericardium.

M-Mode/2D Echocardiography Findings

  • Echo-free space between the epicardium and pericardium: Requires <15 to 35 mL for detection.
  • Swinging heart: May suggest large effusion.
  • Loculated effusion: Particularly relevant post-cardiac surgery or trauma.
  • Fibrin strands: Suggest long-standing effusion either inflammatory, hemorrhagic, or malignant.
  • Inferior vena cava plethora: May indicate increased right atrial pressure.

PW/CW Doppler Findings

  • Respiratory variation of mitral valve and tricuspid valve peak velocities and velocity time integrals suggest cardiac tamponade.

Transesophageal Echocardiography

  • Enhanced detection of loculated effusions or hematoma, particularly post-cardiac surgery or trauma.

Differential Diagnosis

  • Epicardial fat has a speckled or granular echo reflectance, contrasting with pericardial fluid.
  • Pleural effusion may present as a posterior clear space.
  • Location differences: A pericardial effusion is anterior to the descending thoracic aorta, while a pleural effusion is posterior.
  • Respiratory changes: A pericardial effusion does not change position with respiration, in contrast to pleural effusion which may.

Important Notes

  • A patient with pericarditis may have no evidence of pericardial effusion on echocardiography (dry pericarditis).
  • When a large effusion is present, differential diagnoses such as mitral valve prolapse or other valvular prolapses may not be valid until the effusion resolves.
  • The pericardial friction rub can have three components tied to:
    • Early ventricular diastolic filling.
    • Atrial systole.
    • Ventricular systole.
  • A positive serum antinuclear antibody test (ANA) may indicate lupus as an initial presentation, especially in young women with acute pericarditis and associated effusion (a non-specific finding).
  • The classic ECG finding includes ST elevation with reciprocal changes in AVR (reciprocal ST-segment depression and PR segment depression).