I Am Sore At The Bottom Of My Left Rib

I am sore at the bottom of my left rib cage. I have had bronchitis but am better now. This started after my bout with bronchitis. Went to Doctor last week for bronchitis & he did chest X-ray. Said I have enlarged heart which I already knew. Heart has been in afib but am ok now. Just wondering if I should be concerned or just wait it out and see if it improves. Any ideas as to what this might be?