Pericardial Effusion

Pericardial Effusion

Definition:
Pericardial effusion is the abnormal accumulation of fluid in the pericardial sac (the space between the visceral and parietal pericardium).

🔹 Causes of Pericardial Effusion

• Inflammatory / Infectious
  • Viral pericarditis (most common)
  • Bacterial (including TB)
  • Fungal, parasitic infections
• Non-infectious
  • Autoimmune diseases (SLE, RA, scleroderma)
  • Post-MI (Dressler syndrome)
  • Malignancy (lung, breast, lymphoma, leukemia)
  • Uremia (CKD/ESRD)
  • Hypothyroidism (myxedema)
  • Trauma / Post-surgery
  • Radiation therapy
  • Medications (hydralazine, isoniazid, procainamide, etc.)

🔹 Pathophysiology

• The pericardial sac normally contains 15–50 mL of serous fluid.
• A slow accumulation (chronic) can be large (up to >1000 mL) without symptoms.
• Rapid accumulation (acute) of even 150–200 mL may cause tamponade due to lack of time for pericardial stretching.

🔹 Clinical Features

• Symptoms:
  • Dyspnea, orthopnea
  • Chest discomfort / fullness
  • Dysphagia, hoarseness (due to compression)
• Signs:
  • Muffled heart sounds
  • Reduced intensity of apex beat
  • Dullness over left lung base
  • Pericardial friction rub (if associated pericarditis)
  • Large effusion → “Ewart’s sign” (dullness to percussion + bronchial breathing at left scapular angle due to compression of lung)

🔹Pericardial Effusion- Investigations

• ECG:
  • Low voltage QRS
  • Electrical alternans (swinging heart)
• Chest X-ray:
  • “Water bottle–shaped” enlarged cardiac silhouette
• Echocardiography:
  • Gold standard → detects even small effusions
  • Assesses hemodynamic impact (tamponade signs)
• CT / MRI:
  • Useful for loculated effusions or tumor-related causes

🔹 Pericardial Effusion- Complications

• Cardiac tamponade → life-threatening, with Beck’s triad:
  1. Hypotension
  2. Muffled heart sounds
  3. Raised JVP
• Shock, arrhythmias, sudden death if untreated

🔹 Pericardial Effusion- Management

• Treat underlying cause
  • Antibiotics for infection
  • Dialysis in uremia
  • NSAIDs/Colchicine for pericarditis
  • Steroids for autoimmune cause
• Pericardiocentesis (echo-guided, subxiphoid approach)
  • Indicated for tamponade or diagnostic analysis
• Surgical options:
  • Pericardial window
  • Pericardiectomy (for recurrent / malignant effusions)

✅ Key Exam Pearls:

• ECG finding pathognomonic → Electrical alternans.
• Echo = most sensitive investigation.
• Tamponade is the most feared complication.

Echocardiographic Findings in Pericardial Effusion

1. Detection of Fluid

• Anechoic (dark) space between visceral and parietal pericardium.
• Fluid usually starts behind the posterior LV wall.
• Circumferential effusion = fluid around entire heart.
• Loculated effusion = localized pockets (common post-surgery or TB).

2. Quantification (Size of Effusion)

• Mild (small): <10 mm separation in diastole (≈ <200 mL)
• Moderate: 10–20 mm (≈ 200–500 mL)
• Large: >20 mm (≈ >500 mL)

3. Hemodynamic Impact (Signs of Tamponade)

• Right atrial collapse
  • Occurs in late diastole / early systole
  • Sensitive but not specific
• Right ventricular diastolic collapse
  • Occurs in early diastole
  • Highly specific for tamponade
• Interventricular septal shift
  • With respiration → ventricular interdependence
• Dilated IVC with absent inspiratory collapse
  • Suggests raised right atrial pressure

4. Doppler Findings

• Mitral inflow variation (>25%) with respiration
• Tricuspid inflow variation (>40%) with respiration
• Exaggerated ventricular interdependence (reflects tamponade physiology)

5. Other Echo Clues

• “Swinging heart” in very large effusion (correlates with electrical alternans on ECG)
• Effusion may appear fibrinous (with strands) in TB, malignancy, or chronic cases
• Epicardial fat pad can mimic effusion, but it is echogenic (not anechoic)

✅ Most specific sign of tamponade:
👉 Right ventricular diastolic collapse

✅ Best non-invasive tool for diagnosis + monitoring:
👉 Echocardiography

Imaging in Pericardial Effusion

1. Chest X-ray (CXR)

• Often the first investigation, though insensitive for small effusions.
• Findings:
  • “Water-bottle shaped” / flask-shaped heart (large effusion)
  • Smooth, globular cardiomegaly with sharp margins
  • May see epicardial fat-pad sign (lucent stripe between heart & diaphragm)
  • Pulmonary venous congestion usually absent

2. Echocardiography (Gold Standard)

• Most sensitive & specific modality.
• Detects as little as 20 mL of fluid.
• Findings:
  • Anechoic (dark) space around heart
  • Size estimation (mild, moderate, large)
  • Hemodynamic assessment → tamponade physiology (RA/RV collapse, IVC plethora, Doppler inflow variation)
• TTE (Transthoracic echo) → first choice
• TEE (Transesophageal echo) → useful for small, posterior, or loculated effusions

3. CT Scan

• Superior for detecting loculated effusions and associated pathology (tumor, pericardial thickening, calcification).
• Differentiates between pericardial fluid vs. masses or fat.
• Useful in post-surgical or post-radiation patients.
• Can quantify pericardial thickness (helps in constrictive pericarditis vs. effusion).

4. Cardiac MRI

• Excellent for tissue characterization.
• Differentiates:
  • Simple serous effusion vs. hemorrhagic/malignant effusion (high T1 signal)
  • Effusion vs. pericardial cyst or mass
• Shows pericardial inflammation (pericarditis)
• Most accurate for assessing concomitant constrictive pericarditis

5. Nuclear Medicine (Rarely used)

• Radionuclide imaging can show pericardial inflammation or tumor infiltration but not routine.

✅ Summary Table

Pericardial effusion imaging,,Echocardiography in pericardial effusion,,CT scan pericardial effusion,,MRI pericardial effusion,,Chest X-ray pericardial effusion,,Cardiac tamponade echocardiography,,Right ventricular collapse echo,,Swinging heart pericardial effusion,,Water bottle heart chest X-ray,,Loculated pericardial effusion imaging,,,Echo findings in pericardial effusion,,Doppler signs of tamponade,,Pericardial effusion diagnostic modalities,,MRI pericardial inflammation,,CT pericardial calcification,,Pericardial cyst vs effusion imaging,,Dilated IVC pericardial effusion,,Beck’s triad imaging correlation,,Hemorrhagic pericardial effusion MRI,,Imaging of pericardial diseases,,,Best imaging modality for pericardial effusion,,Echocardiography signs of cardiac tamponade,,Role of CT and MRI in pericardial effusion,,Chest X-ray features of pericardial effusion,,Minimum volume of fluid detected by echocardiography,,Differentiating pericardial effusion from pericardial cyst,,MRI tissue characterization in pericardial disease,,CT detection of loculated pericardial effusion,,Imaging approach in pericardial effusion and tamponade,,Echo-guided pericardiocentesis

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