pericardial disease: pericardial effusion, pericarditis 

for pericardial tamponade = cardiac tamponade, please refer to “tamponade”

EKG

https://emergencymedicinecases.com/tag/pericarditis/

POCUS:
vanPOCUS: Pericardial Effusion and Tamponade
Pleural Effusions, Part 1
Pleural Effusions, Part 2
http://5minsono.com/quantifying-pleural-effusions/