Hi Thank you for asking HCM I have gone through your query.Your problem is most likely Costochondritis. Pain while palpation on rib area is characteristic.As you have done ECG and tread mill test cardiac cause is most unlikely.If you don t have any gastric discomfort or heartburn then pain due to gastric reflux also unlikely.For my patients with Costochondritis i treat with anti inflammatory gels of diclofenac or nimusulide for local application.I give oral tablets of same if there is more pain.If not relieving by this then i recommend local injection of corticosteroids or anesthetics.Hope this may help you. Let me know if you have any further query.