This article describes the use of heart rate variability biofeedback (HRV) in the practice of psychotherapy, including the emergence of psychological trauma. A model for understanding this phenomenon based on attentional state will be proposed. In addition techniques for transforming this “side effect” into a therapeutic opportunity will be described. The clinical case of DG, a successful business executive who was able to significantly improve his level of function, will be used to illustrate critical points.