Sudden cardiac death and post-traumatic stress disorder: More research is needed.

Sudden cardiac death is an event which is traumatic for the individuals, who survive and their relatives. Very few research is concentrated on these survivals and the symptoms arising from post-traumatic stress disorders. In this journal, Birk et al. report on twelve eligible cardiac arrest survivors contacted, of which ten were enrolled. The authors report on heart rate variability biofeedback, which is, according to the authors, a promising non-pharmacologic approach for reducing anxiety. The intervention was comprised of daily sessions of diaphragmatic paced breathing and real-time monitoring of cardiac activity guided by a smartphone app and heart rate monitor. Ninety percent of the patients had good scores for intervention acceptability and feasibility, and 80 % reported good scores for its appropriateness and usability for reducing fear. Trait anxiety decreased significantly pre-to-post intervention. We comment on this finding highlighting other studies targeting sudden cardiac death and supporting that more research with very large randomized clinical trials is needed.