Atrial Enlargement I Just Had An EKG Which Said I Had A Right Atrial Enlargement. Does This Indicate Anything Serious?

I just had an EKG which said I had a right atrial enlargement. Does this indicate anything serious? - atrial enlargement

I also incomplete right bundle branch block. I went to a cardiologist and ordered a Holter monitor and an echo. Is this a serious condition. I had rheumatic fever as a child and I know regurg, mitral. Thank you!