- Normal fluid 15 – 35 ml
- > 50 ml is abnormal
- Cardiac failure, renal or hepatic insufficiency, bacterial, viral or fungal infection, neoplasia (lung, breast or lymphoma)
Imaging
- Chest Xray
- Seen only when 200 ml of fluid present
- Symmetric enlargement of cardiac silhouette resulting in flask like configuration
- Cardiophrenic angles become acute
- Curvilinear lucency along left hear border
- Lateral view: loss of retrosternal clear space. Fluid separates substernal fat from epidural fat
- ECHO
- Primary investigation
- Small amount fluid seen as thin anechoic area in systole behind left ventricle free wall
- Limited in obesity
- False positive due to atelectasis, pleural effusion, anterior epicardial fat
- Common sites of fluid accumulation (gravity dependent): posterolateral wall of left ventricle, inferolateral to right ventricle, superior pericardial recess
- CT/MR
- Best demonstrates loculated effusion, hemorrhage, inflammation, thickening
- Distance between pericardial leaflets > 4 mm is abnormal
- Moderate effusion if 5 mm or more anterior to right ventricle
- T1 hypointense, T2 hyperintense
- T1 hyperintense if protein rich
- GRE shows blood products
- Pericardial thickening, leaflet enhancement points to inflammation/neoplasia. Nodularity favors neoplasia
Cardiac tamponade
- Severe acute effusion compressing cardiac chambers
- Limits ventricular filling
- Decreases cardiac output
- ECHO: right atrial compression, diastolic collapse of right ventricle free wall, increased variation of mitral and tricuspid diastolic blood flow velocities, abnormal right-sided venous flow, decreased IVC collapsibility in inspiration
Read more
Restrepo, Carlos S., et al. “Primary pericardial tumors.” Radiographics 33.6 (2013): 1613-1630.