CAUSES :
β’ Physiology of tamponade depends on size and rapidity of development
β’ Uremia
β’ Neoplasm - breast, lung, lymphoma, leukemia
β’ Postmyocardial infarction (Dresslerβs)
β’ Postoperative - as high as 30% post pericardiotomy
β’ HIV - particularly symptomatic
β’ Other viruses - Coxsackie group B, influenza, echo, herpes
β’ Bacterial infection - S. aureus, M.tuberculosis, S. pneumoniae (rare)
β’ Fungal infection - M. capsulatum
β’ Lupus and rheumatologic disease
β’ Trauma
β’ Placement of central venous catheter, pacer wires
β’ Hypothyroidism
β’ Drug induced
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DIFFERENTIAL DIAGNOSIS
β’ Tension pneumothorax
β’ Acute RV failure
β’ Chronic obstructive pulmonary disease
β’ Constrictive pericarditis
β’ Acute acceleration of chronic bronchitis
β’ Acute pulmonary emboli
β’ Fat emboli
β’ Excessive or rapid administration of fl uids
β’ Abdominal distention from ascites or ileus
β’ Increased intrathoracic pressure from pneumothorax, hemothorax, airway obstruction, or mechanical ventilation
β’ Administration of vasopressors
β’ CBC
β’ ESR
β’ Cardiac enzymes to rule out acute myocardial infarction
β’ Antinuclear antibodies (ANA)
β’ Rheumatoid factor
β’ BUN/creatinine
β’ Pericardial fluid for - culture of bacteria, fungus, mycobacteria, Gram stain, hematocrit, cell count, cytology, glucose, protein, rheumatoid factors, complement levels
. ECG : May show sinus tachycardia, low voltage QRS complexes, diffuse ST segment elevation and PR segment depression of pericarditis
. Electrical alternans (R wave variation from beat to beat)
. Electrical alternans is seen in 10-20% of cases of tamponade and 50-60% of these are neoplastic in origin
. Right heart catheterization
. Equalization (within 2-3 mm) of right atrial, pulmonary artery diastolic pressure, pulmonary capillary wedge pressure, left atrial and left ventricular diastolic pressure
. The intracardiac diastolic pressure will approximate the intrapericardial pressure
. The dip and plateau pattern of constriction or restriction pericardial disease is absent
. Loss of Y descent on atrial wave form
IMAGING :
. Chest x-ray: May or may not show enlargement of cardiac shadow (if > 250 cc fluid present)
. Echocardiography:
. Diagnostic cardiac compression
. Doppler - right sided transvalvular flow greatly exaggerated; left sided flows greatly reduced with inspiration