MioAtlas
G6: Pericardium

Cardiac tamponade

Medical emergency and acute or subacute cardiac compression syndrome caused by accumulation of pericardial fluid under tension that elevates intrapericardial pressure above normal intracavitary diastolic pressures, impeding ventricular filling.

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Definition

Medical emergency and acute or subacute cardiac compression syndrome caused by accumulation of pericardial fluid under tension that elevates intrapericardial pressure above normal intracavitary diastolic pressures, impeding ventricular filling diastole after diastole, causing equalization of diastolic pressures, critical drop in stroke volume, and obstructive shock [C2] [G6-02] [M5].

Severity criteria

  • Single grade: Decompensated cardiac tamponade characterized by the pathophysiological and hemodynamic triad:
    • Systemic arterial hypotension: Systolic blood pressure < 90 mmHg with narrowed pulse pressure (< 25–30 mmHg) [C2] [G6-02].
    • Quantitative pulsus paradoxus: As defined in reference literature, «Pulsus paradoxus is defined as a fall of systolic blood pressure of >10 mmHg during the inspiratory phase. Pulsus paradoxus can be observed in cardiac tamponade» [B5], and in this clinical entity «During cardiac tamponade and acute asthma, biventricular interdependence (series and parallel) plays an important role in the inspiratory decrease in left ventricular stroke volume.» [B5]. Therefore, «Early recognition of Pulsus paradoxus in the emergency room can help to diagnose rapidly cardiac tamponade.» [B5].
    • Severely elevated jugular venous pressure: Mean venous pressure > 15 cmH₂O with marked jugular engorgement [B3] [C2].
    • Equalization of diastolic pressures: Mean right atrial pressure, RV end-diastolic pressure, and pulmonary capillary wedge pressure elevated and equalized within a margin of ≤ 5 mmHg (typically 15–22 mmHg) [G6-02] [M5].
    • Diagnostic echocardiographic criteria:
    • Right atrial diastolic collapse lasting more than 1/3 of the cardiac cycle [C2] [G6-01].
    • Early diastolic collapse of the right ventricular free wall [C2] [G6-01].
    • Inferior vena cava plethora (diameter > 21 mm with inspiratory collapse < 50%) [C2] [G6-01].
    • Exaggerated respiratory variation of transvalvular Doppler flow (inspiratory transmitral drop > 25–30% and tricuspid increase > 40–50%) [C2] [G6-01].

Findings by layer

Hemodynamics

  • Obstructive shock with hemodynamic collapse [C2] [G6-02] [M5]:
    • Mean right atrial pressure: Elevated (15–22 mmHg) [C2] [M5].
    • Mean pulmonary capillary wedge pressure: Elevated and equalized with right-sided pressure (16–22 mmHg) [M5].
    • Systemic blood pressure: Severe arterial hypotension (systolic blood pressure 75–88 mmHg, diastolic blood pressure 55–65 mmHg) with thready pulse [C2] [G6-02].
    • Cardiac output: Severely reduced (1.8–3.2 L/min) [C2].
    • LV end-diastolic volume: Severely diminished due to extrinsic compression (< 60–75 mL) [G6-01] [M5].
    • LV ejection fraction (left ventricular ejection fraction): Compensatory hyperdynamic (≥ 60–70%) in compressed chambers [C2].

Rhythm

  • Marked sinus tachycardia (sinus tachycardia, heart rate typically 110–135 bpm) reactive to adrenergic stimulation to compensate for low stroke volume [C2] [G6-02].

ECG

  • Low voltage QRS complex (low voltage): QRS voltage < 0.5 mV in limb leads [E1] [G6-02].
  • Electrical alternans: Beat-to-beat variation in QRS amplitude caused by pendular swinging motion of the heart within the pericardial fluid mantle [C2] [G6-02].
  • Constant sinus tachycardia [C2].

Heart sounds and murmurs

  • Muffled, distant heart sounds (classic Beck triad: hypotension, jugular venous distention, and distant heart sounds) [G6-02].
  • Absent cardiac murmurs [C2].
  • Absence of third heart sound (S3) or pericardial knock [G6-02] [M5].

Arterial pulse

  • Severe pulsus paradoxus: Inspiratory systolic blood pressure drop > 10 mmHg (frequently > 15–25 mmHg) [B5] [C2] [G6-02].
  • Small-volume thready pulse (parvus) and tachycardic [B4].

Jugular venous pulse

  • Extreme jugular venous distention with very high venous pressure (mean venous pressure in cmH₂O > 15–20 cmH₂O) [B3] [C2].
  • Pathognomonic venous morphology: Deep and prominent x descent with absent or practically flat y descent (absent y descent) due to continuous impediment to ventricular filling throughout diastole [B3] [G6-02] [M5].
  • Absence of Kussmaul sign in pure tamponade [G6-02] [M5].

Maneuvers

  • Inspiration: Accentuates the drop in systolic blood pressure (> 10 mmHg) mediated by ventricular interdependence [B5] [M5].

Simulator severity grades

Simulator severity grades: Single grade
Baseline rhythm: Sinus Tachycardia

Also known as: Cardiac tamponade · Pericardial tamponade · Pericardial compressive syndrome · Acute cardiac tamponade · Tamponade

Other pathologies in this group

Related clinical comparisons

Sources

  1. [B3] The jugular venous pressure revisited . Cleve Clin J Med (2013) . DOI: 10.3949/ccjm.80a.13039 PubMed: 24085809
  2. [B4] The Carotid Pulse . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250154
  3. [B5] Pulsus paradoxus . Eur Respir J (2013) . DOI: 10.1183/09031936.00138912 PubMed: 23222878
  4. [C2] 2025 ESC Guidelines for the management of myocarditis and pericarditis . Eur Heart J (2025) . DOI: 10.1093/eurheartj/ehaf192 PubMed: 40878297
  5. [E1] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191097 PubMed: 19228820
  6. [G6-01] American Society of Echocardiography clinical recommendations for multimodality cardiovascular imaging of patients with pericardial disease: endorsed by the Society for Cardiovascular Magnetic Resonance and Society of Cardiovascular Computed Tomography . J Am Soc Echocardiogr (2013) . DOI: 10.1016/j.echo.2013.06.023 PubMed: 23998693
  7. [G6-02] Acute cardiac tamponade . N Engl J Med (2003) . DOI: 10.1056/NEJMra022643 PubMed: 12917306
  8. [M5] Pericardial disease . Circulation (2006) . DOI: 10.1161/CIRCULATIONAHA.105.561514 PubMed: 16567581