Hi Thank you for asking HCM I have gone through your query.As you have taken ECG and sonography problems with heart is most unlikely.You can take a chest x ray to rule out any problems of lungs also.If those are clear your problem is most likely costochondritis.While palpating on rib area pain will be there for that.For such condition in my patients i treat with anti inflammatory gels of diclofenac or nimusulide for local application.I also give them oral tablets of same if pain is more.If there is no improvement then i recommend local injection of corticosteroids or anesthetics.Hope this may help you. Let me know if you have any further query.