Does the presence of trace pericardial effusion on echocardiogram mean than one once has pericarditis at one point? are those with trace effusions at higher risk of pericarditis? thanks:-?

If you have no rheumatological or autoimmune disorders, and the rest of the echocardiogram is normal, I consider a trace amount of pericardial effusion as physiologic and not due to pericardial pathology & doesn't predispose one to pericarditis. However autoimmune disorders may have trace amounts of pericardial fluid as part of their inflammatory process.

A small amount of fluid in the pericardial sac is normal and needed for lubrication.