Effects of anxiety on QT dispersion in healthy young men

QT dispersion (QTd) is the maximal interlead difference in QT interval on the surface 12-lead electrocardiogram (ECG). An increase in QTd is found in various cardiac diseases and reflects cardiac autonomic imbalance. It has recently been associated with increased anxiety levels, thereby predisposing affected individuals to fatal heart disease. This is the biggest study to assess QTd in anxiety, as a marker of anxiety-induced cardiac dysregulation.

QTd and rate-corrected QTd (QTcd) were measured in 726 physically and mentally healthy male volunteers, aged 21.23 +/- 1.25 years (range 20-26). The Spielberger State-Trait Anxiety Inventory (STAI) was scored concomitantly. The intra- and inter-observer reproducibilities of QTd were highly correlated (r = 0.92, p < 0.001; r = 0.93, p < 0.001, respectively). QTd and QTcd significantly correlated with the STAI-I subscale (State Anxiety Scale) (r = 0.529, p < 0.001; r = 0.518, p < 0.001, respectively) and STAI-2 subscale (Trait Anxiety Scale) (r = 0.601, p < 0.001; r = 0.563, p < 0.001, respectively).

The State Anxiety Scale and the Trait Anxiety Scale are associated with an increase in QTd. This association may result from sudden and prolonged anxiety and, in turn, a decrease in vagal modulation and/or increase in sympathetic modulation. This is the first study that shows that increased QTd can serve as a state/trait marker. But further large-scale epidemiological studies are needed to determine if increased QTd is a risk factor for sudden cardiac death in patients with anxiety.