Chest pain and extend towards back.

My mother 50years old having chest pain in middle and that pain also goes towards back from last 1years . Also pain in chest starts when she walks . We did ecg and echo last year , both two report found okay . So she was under treatment of gastroenterologist . But no such improvement. After one year now when we did ecg and echo report showing grade 1 left ventricular dystolic dysfunction . Now she is under treatment of cardiologist But why we found ecg and echo normal in last year ? Then suddenly this year report is different . She also has diabetes and high pressure also little triglycerides high as per this year report . Kindly let us know is this actually hear related issue then last year why ecg and echo report doesn't show any thing ?