What could cause IGG to be over 3, 000 with normal IGE, IGA. 2 weeks later was diagnosis with pericardial effusion (1 liter blood) Any connection?

Agree need diagnosi. We need a diagnosis and you need further evaluation. Was the pericardial effusion due to blood? Your evaluation needs ot clarify this. The elevated IgG is not specific but can be present for a variety of reasons. You may need to see a rheumatologist to help clarify this.