QT variability versus sympathetic cardiac activity in patients with major depression and patients with panic disorder

Beat-to-beat variability of the QT interval is a risk predictor of sudden cardiac death. Increased QT variability was also reported in patients with major depression and patients with panic disorder and it has been suggested that QT variability is a marker of sympathetic cardiac activity. In this paper, I review these findings and discuss them in relation to directly assessed sympathetic cardiac activity by means of noradrenaline spillover.M. Baumer