Pericardial effusion – accomulation of fluid within the pericardium

Causes of effusion
infection: viral, bacterial, TB, fungal – viral, purulent, TB
drugs and toxins
autoimmune disease
metabolic disorders – uremia, dialysis, hypothyroid
collagen vascular diseases
neoplasitc – lung and breast cancer, Hodgkin lymphoma, mesothelioma
degenerative
trauma
radiation
iatrogenic – post surgery
Post MI
aortic dissection
idiopathic

The normal pericardium can stretch to accommodate increases in pericardial volume.  The rate of fluid accumulations and the amount of fluid can lead to increases in intrapericardial pressure eventual resulting in impaired cardiac filing and cardiac function.  Rapid development of effusions is more likely to cause this.  Effusions can also be subacute and chronic.

Diagnosis: by echo
EKG: electric alternans (beat to beat shift in the QRS axis, amplitude, and/or morphology, also can see alternans of P waves)

Treatment is aimed to correct the underlying cause of the effusion, if tamponade is present then pericardiocentesis is needed