Table 2

Diagnosis of cardiac tamponade3

*Jugular venous distension is less notable in hypovolaemic patients or in “surgical tamponade”. An inspiratory increase or lack of fall of the pressure in the neck veins (Kussmaul sign), when verified with tamponade, or after pericardial drainage, indicates effusive–constrictive disease.
†Heart rate is usually >100 beats/min, but may be lower in hypothyroidism and in uraemic patients.
‡Pulsus paradoxus is defined as a drop in systolic blood pressure >10 mm Hg during inspiration whereas diastolic blood pressure remains unchanged. It is easily detected by simply feeling the pulse, which diminishes significantly during inspiration. Clinically significant pulsus paradoxus is apparent when the patient is breathing normally. When this sign is present only in deep inspiration it should be interpreted with caution. The magnitude of pulsus paradoxus is evaluated by sphygmomanometry. If the pulsus paradoxus is present, the first Korotkoff sound is not heard equally well throughout the respiratory cycle, but only during expiration at a given blood pressure. The blood pressure cuff is therefore inflated above the patient’s systolic pressure. Then it is slowly deflated while the clinician observes the phase of respiration. During deflation, the first Korotkoff sound is intermittent. Correlation with the patient’s respiratory cycle identifies a point at which the sound is audible during expiration, but disappears when the patient breathes in. As the cuff pressure drops further, another point is reached when the first blood pressure sound is audible throughout the respiratory cycle. The difference in systolic pressure between these two points is the clinical measure of pulsus paradoxus. Pulsus paradoxus is absent in tamponade complicating atrial septal defect and in patients with significant aortic regurgitation.
§Occasional patients are hypertensive, especially if they have pre-existing hypertension.
¶Febrile tamponade may be misdiagnosed as septic shock.
**Right ventricular collapse can be absent in raised right ventricular pressure and right ventricular hypertrophy or in right ventricular infarction.
††If after drainage of pericardial effusion intrapericardial pressure does not fall below atrial pressure, then effusive–constrictive disease should be considered.
LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle; VCI, inferior vena cava.
  • Clinical presentation

Raised systemic venous pressure*, hypotension†, pulsus paradoxus‡, tachycardia§, dyspnoea or tachypnoea with clear lungs
  • Precipitating factors

Drugs (cyclosporin, anticoagulants, thrombolytics, etc), recent cardiac surgery, indwelling instrumentation, blunt chest trauma, malignancies, connective tissue disease, renal failure, septicaemia¶
  • ECG

Can be normal or non-specifically changed (ST-T wave), electrical alternans (QRS, rarely T), bradycardia (end stage), electromechanical dissociation (agonal phase)
  • Chest x ray

Enlarged cardiac silhouette with clear lungs
  • M mode/2D echocardiogram

Diastolic collapse of the (1) anterior RV free wall**, RA collapse, LA and rarely LV collapse, increased LV diastolic wall thickness “pseudohypertrophy”, VCI dilatation (no collapse in inspirium), “swinging heart”
  • Doppler

Tricuspid flow increases and mitral flow decreases during inspiration (reverse in expiration)
Systolic and diastolic flows are reduced in systemic veins in expirium and reverse flow with atrial contraction is increased
  • M mode colour Doppler

Large respiratory fluctuations in mitral/tricuspid flows
  • Cardiac catheterisation

  1. Confirmation of the diagnosis and quantification of the haemodynamic compromise:

    • –RA pressure is raised (preserved systolic x descent and absent or diminished diastolic y descent)

    • –Intrapericardial pressure is also raised and virtually identical to RA pressure (both pressures fall in inspiration)

    • –RV mid-diastolic pressure raised and equal to the RA and pericardial pressures (no dip-and-plateau configuration)

    • –Pulmonary artery diastolic pressure is slightly raised and may correspond to the RV pressure

    • –Pulmonary capillary wedge pressure is also raised and nearly equal to intrapericardial and right atrial pressure

    • –LV systolic and aortic pressures may be normal or reduced

  2. Documenting that pericardial aspiration is followed by haemodynamic improvement††

  3. Detection of the coexisting haemodynamic abnormalities (LV failure, constriction, pulmonary hypertension)

  4. Detection of associated cardiovascular diseases (cardiomyopathy, coronary artery disease)

  • RV/LV angiography

Atrial collapse and small hyperactive ventricular chambers
  • Coronary angiography

Coronary compression in diastole