Pericardial effusion and tamponade

Background

File:Pericardial anatomy diagram.png

(d) Pericardial cavity, part of the inferior mediastinum, in relation to (a) superior mediastinum; (c) pleural cavities; and (e) diaphragm.

File:Pericardium anatomy.png

Anatomy of the pericardium.

File:Pericardial pressure volume curve.png

Pericardial pressure-volume relationships. Rapid accumulation (left curve) causes tamponade with small volumes; slow accumulation (right curve) allows pericardial stretching.

• Pericardial effusion: abnormal accumulation of fluid in the pericardial space
• Cardiac tamponade: hemodynamic compromise from pericardial fluid compressing the heart
  • Rate of accumulation matters more than volume
  • Acute: as little as 100-150 mL can cause tamponade (e.g., trauma)
  • Chronic: up to 1-2 L may accumulate before tamponade (e.g., malignancy, uremia)
• Pathophysiology: increased pericardial pressure → decreased RV filling → decreased cardiac output
• Always consider in PEA
• Always consider in penetrating thoracic trauma within the cardiac box (80% result in tamponade)
  • Gunshot wounds less likely to cause tamponade (larger pericardial defect allows decompression)
  • RV is most commonly injured chamber due to anterior position

Etiology

• Hemopericardium:
  • Trauma (penetrating or blunt), iatrogenic (central line, pacemaker, post-cardiac surgery)
  • Ventricular free wall rupture (post-MI, typically day 3-5)
  • Aortic dissection (type A with rupture into pericardium)
  • Bleeding diathesis / anticoagulation
• Non-hemorrhagic:
  • Malignancy (most common cause of large effusions): lung, breast, lymphoma, melanoma
    • Melanoma has particular predilection for cardiac metastasis
  • Pericarditis (viral, bacterial, tuberculous)
  • Uremia (renal failure)
  • HIV (infection, Kaposi sarcoma, lymphoma)
  • Autoimmune (SLE, rheumatoid arthritis, scleroderma)
  • Post-radiation, hypothyroidism/myxedema
  • Idiopathic (up to 50% of large effusions)

Clinical Features

• Chest pain, dyspnea, cough, fatigue
• Tachycardia (most reliable sign; bradycardia is ominous/preterminal)
• Narrow pulse pressure
• Friction rub (may be absent with large effusion)
• Pulsus paradoxus: >10 mmHg drop in systolic BP during inspiration
• Beck's triad (present in only ~33% of cases):
  • Hypotension
  • Muffled heart sounds
  • JVD (elevated CVP)
• Kussmaul sign: paradoxical rise in JVP with inspiration
• Hepatomegaly, peripheral edema (if chronic)
• May present as PEA arrest or cardiogenic shock

Differential Diagnosis

• Tension pneumothorax (absent breath sounds, tracheal deviation)
• Massive pulmonary embolism
• Acute MI / cardiogenic shock
• Constrictive pericarditis
• Acute heart failure
• Aortic dissection

Evaluation

ECG

• Sinus tachycardia (most common finding)
• Electrical alternans (pathognomonic but insensitive — alternating QRS amplitude)
• Low voltage:
  • Limb leads: all QRS <5 mm or I+II+III <15 mm
  • Precordial leads: all QRS <10 mm or V1+V2+V3 <30 mm
• PR depression (if associated pericarditis)

CXR

File:Massive pericardial effusion CXR.jpg

Massive pericardial effusion on chest x-ray

• Enlarged cardiac silhouette (water bottle sign)
• May be normal with small or acute effusions
• Not sensitive for early detection

Pulsus Paradoxus

• >10 mmHg decrease in systolic BP during inspiration
• Measure with manual sphygmomanometer (inflate above systolic, slowly deflate noting first Korotkoff sounds in expiration vs inspiration)
• False negatives: aortic regurgitation, ASD, severe hypotension, positive-pressure ventilation

Bedside Ultrasound (Test of Choice in ED)

File:Pericardial effusion echo.jpg

Transthoracic echo of pericardial effusion showing "swinging heart"

File:Pericardial effusion US.jpg

Pericardial effusion on ultrasound

• POCUS is the fastest and most reliable bedside diagnostic tool
• Key views: subxiphoid (most sensitive), parasternal long axis (PLAX), apical 4-chamber
• Distinguish from pleural effusion on PLAX: pericardial effusion tracks anterior to descending aorta; pleural effusion tracks posterior

Classic Findings of Tamponade

• Diastolic collapse of RA (earliest sign; >1/3 of cardiac cycle = significant)
• Diastolic collapse of RV (more specific)
• Plethoric (non-collapsing) IVC (>2 cm, <50% collapse — sensitive but nonspecific)
• Swinging heart within large effusion

Advanced Echo Assessment

• M-mode: position through RV free wall on PLAX to identify diastolic collapse timing
• Doppler — valvular pulsus paradoxus:
  • Mitral inflow variation >25% → likely tamponade
  • Tricuspid inflow variation >40% → likely tamponade
  • Helpful when RV is thickened (chronic pulmonary hypertension)

Management

Immediate Stabilization

• IV fluid bolus 500-1000 mL NS (patient is preload-dependent)
• Avoid preload-reducing medications: nitroglycerin, diuretics, morphine
• Avoid positive-pressure ventilation if possible (reduces preload further)
• Vasopressors as temporizing bridge (norepinephrine preferred)
• Position patient upright or leaning forward if tolerated

Pericardiocentesis (Definitive for Non-hemorrhagic Tamponade)

• Indications: hemodynamic compromise, suspected purulent pericarditis
• Ultrasound-guided approach preferred (reduces complications)
• Subxiphoid approach:
  • Insert needle 1-2 cm inferior to left xiphosternal junction, aimed toward left shoulder
  • Advance at 30-45° angle under US guidance
  • As little as 30-50 mL removal can dramatically improve hemodynamics
• Send fluid for: cell count, protein, LDH, glucose, cytology, gram stain/culture, AFB
• Complication rate <2% with US guidance (vs ~20% blind)

Traumatic Tamponade

• Pericardiocentesis is a temporizing measure only — definitive treatment is thoracotomy
• Hemorrhagic tamponade will reaccumulate
• IV fluid resuscitation and emergent surgical consultation
• Can occur if ECG read as STEMI and heparin started inadvertently

Specific Etiologies

• Uremic tamponade: emergent dialysis
• Malignant effusion: pericardiocentesis + consider pericardial window for recurrent effusions
• Post-MI free wall rupture: emergent cardiac surgery

Disposition

• Unstable traumatic tamponade: emergent OR for thoracotomy
• All patients with tamponade physiology: ICU admission
• Large effusion without tamponade: admit with cardiology consultation
• Small effusion, stable, known etiology: may be managed as outpatient with close follow-up
• Consult: cardiology and/or CT surgery

See Also

• Pericardiocentesis
• Thoracic trauma
• Pericarditis
• Cardiac ultrasound
• PEA

External Links

• Medscape - Cardiac Tamponade

References

• Adler Y, et al. 2015 ESC Guidelines for the diagnosis and management of pericardial diseases. Eur Heart J. 2015;36(42):2921-2964. PMID 26320112
• Spodick DH. Acute cardiac tamponade. N Engl J Med. 2003;349(7):684-690. PMID 12917306
• Ristic AD, et al. Triage strategy for urgent management of cardiac tamponade: a position statement of the ESC. Eur Heart J. 2014;35(34):2279-2284. PMID 25002085