Why biofeedback would help this problem: People's hearts do not beat at a steady rate. Rather, they change with exercise, emotions, and breathing. There is a well known relationship between chest pain caused by anxiety or incorrect breathing patterns and heart rate variability. If variability is too low in relation to breathing, non-cardiac chest pain may be observed. Training people to increase the variability of their heart rates in relation to their breathing results in decreased symptoms of non-cardiac related chest pain.