Pericardial Diseases

Pericardial Anatomy & Physiology - Heart's Protective Sac

• Layers: Two main parts.
  • Outer: Fibrous pericardium (tough, inelastic).
  • Inner: Serous pericardium.
    • Parietal layer (lines fibrous).
    • Visceral layer (epicardium; covers heart).
• Pericardial Cavity: Potential space between serous layers.
  • Contains 15-50 mL of serous fluid (plasma ultrafiltrate) for lubrication.
• Functions:
  • Fixes heart, limits motion.
  • Prevents overfilling.
  • Reduces friction.
  • Barrier to infection/inflammation.

⭐ The pericardium has a limited elastic reserve; rapid fluid accumulation (e.g., >200 mL) can cause tamponade, while slow accumulation (e.g., >1-2 L) may be tolerated initially due to stretching over time.

Acute Pericarditis - Fiery Heart Ache

• Definition: Inflammation of the pericardium, typically < 2 weeks duration.
• Etiology:
  • Idiopathic (most common)
  • Infectious: Viral (Coxsackie B, Echovirus), Bacterial (TB), Fungal
  • Post-MI: Early (peri-infarction pericarditis), Late (Dressler's syndrome, weeks-months post-MI)
  • Uremia, Neoplasm, Autoimmune (SLE, RA), Trauma, Drugs (Hydralazine, Procainamide)
• Clinical Features:
  • Chest Pain: Pleuritic (sharp, worse with inspiration/cough), postural (worse supine, relieved by sitting up/leaning forward), radiates to trapezius ridge (pathognomonic).
  • Pericardial Friction Rub: Scratchy, triphasic sound (atrial systole, ventricular systole, early ventricular diastole); best heard at left sternal border with diaphragm, patient leaning forward.
  • Fever, dyspnea, malaise.
• ECG Findings (sequential stages):
  • Stage 1: Diffuse ST elevation (concave up), PR depression (most specific early sign).
  • Stage 2: ST segments normalize, T waves flatten.
  • Stage 3: T wave inversion.
  • Stage 4: ECG normalizes.
• Diagnosis: ≥2 of 4 criteria: typical chest pain, pericardial rub, characteristic ECG changes, new/worsening pericardial effusion.
• Treatment:
  • NSAIDs (Ibuprofen 600-800 mg TID, Aspirin 2-4 g/day) + Colchicine (0.5-0.6 mg BID for 3 months) to ↓ recurrence.
  • Corticosteroids: Refractory cases or if NSAIDs contraindicated (avoid in viral pericarditis if possible).

⭐ Widespread concave ST elevation and PR depression (except aVR, V1) are hallmark ECG findings in Stage 1 acute pericarditis.

📌 PERICARDITIS Mnemonic for causes: Post-MI (Dressler's) End-stage renal disease (Uremia) Rheumatic fever/RA Infection (Viral, Bacterial, TB) Cancer (Neoplasm) Autoimmune (SLE) Radiation Drugs (Hydralazine, Procainamide) Idiopathic Trauma Inflammatory bowel disease Surgery (Post-pericardiotomy syndrome)

Pericardial Effusion & Tamponade - Fluid Fiasco, Pressure Cooker

• Pericardial Effusion: Abnormal fluid (>50 mL; normal 15-50 mL) in pericardial sac.
  • Etiology: Infection (TB, viral), malignancy, uremia, autoimmune, post-MI (Dressler's).
  • Sx: Often asymptomatic. Dyspnea, cough. Muffled heart sounds. Ewart's sign (dullness L scapula).
  • Dx:
    • CXR: Globular "water bottle" heart (>250 mL).
    • ECG: Low voltage QRS, electrical alternans (pathognomonic).
    • Echo: Gold standard; quantifies, may show swinging heart.
• Cardiac Tamponade: Life-threatening cardiac compression due to ↑intrapericardial pressure.
  • Patho: ↓Venous return → ↓Diastolic filling (RA/RV collapse) → ↓CO.
  • Clinical:
    • Beck's Triad: Hypotension, ↑JVP (Distended Neck Veins), Muffled heart sounds. 📌 3 D's: Distant heart sounds, Distended neck veins, Decreased arterial pressure.
    • Pulsus paradoxus: ↓SBP >10 mmHg on inspiration.
    • Kussmaul's sign (occasional; more in constriction).
  • Dx (Echo): RA & RV diastolic collapse (earliest, most sensitive), IVC plethora, swinging heart.
  • Rx: Urgent pericardiocentesis. IV fluids. Avoid diuretics.

⭐ Electrical alternans on ECG, caused by the heart swinging in a large effusion, is highly specific for pericardial effusion and impending tamponade.

Constrictive Pericarditis - The Unyielding Armor

Chronic inflammation → rigid, fibrotic pericardium → impaired diastolic filling of all chambers.

• Etiology: TB (India), idiopathic, post-surgery, post-radiation.
• Clinical: Dyspnea, edema, ascites.
  • Kussmaul's sign (JVP↑ inspiration).
  • Pericardial knock (early diastolic).
  • Friedreich's sign (prominent 'y' descent).
• Investigations:
  • ECG: Low voltage, AF.
  • CXR: Pericardial calcification (~50%).
  • Echo: Thickened pericardium (>2mm), septal bounce.
  • CT/MRI: Best for thickness (>4mm).
  • Cath: Equalized diastolic pressures (within 5 mmHg), dip-and-plateau (√ sign).
• Management: Pericardiectomy (definitive). Diuretics for symptoms.

⭐ Kussmaul's sign: Paradoxical JVP rise on inspiration; classic, differentiates from tamponade (usually absent).

High‑Yield Points - ⚡ Biggest Takeaways

• Acute pericarditis: Pleuritic chest pain, friction rub, diffuse ST elevation.
• Cardiac Tamponade: Beck's triad (hypotension, JVD, muffled heart sounds), pulsus paradoxus (>10 mmHg drop).
• Constrictive Pericarditis: Kussmaul's sign, pericardial knock, pericardial calcification.
• Dressler's Syndrome: Late post-MI pericarditis (weeks after).
• Large effusion ECG: Low QRS voltage, electrical alternans.
• Viral infections (Coxsackie B) are most common cause of acute pericarditis.