META-ANALYSIS: QT DISPERSION IN PATIENTS WITH ANXIETY DISORDERS
Authors: Igor Kelmanson
Background: Exaggerated dispersion of repolarization is likely to play a role in both the initiation and the maintenance of malignant ventricular arrhythmias. It was proposed that the inter-lead QT interval differences within a 12-lead ECG termed “QT dispersion” might reflect regional differences in myocardial refractoriness, and that this might predict cardiac dysrhythmias. Little is known on possible associations between anxiety in the otherwise healthy patients and QT dispersion, although autonomous disturbance, which may predispose to abnormal repolarization, is characteristic of anxiety disorders.
Aim: The study aimed at performing a meta-analysis of the relevant available publications.
Methods: A MEDLINE search from 1990 through 2012 at PubMed (NLM) was performed. All fields search for index terms ”QT dispersion” and ”anxiety” was done. Case-control studies and the surveys were included into analysis, provided they encompassed apparently healthy patients who have been evaluated for the level of anxiety symptoms with validated inventories. Outcome measures were either crude or heart rate-corrected QT dispersions.
Results: Five studies entered the analysis that encompassed 580 patients with calculated mean age of 36.8 years (SE = 5.5). The values of crude and rate-corrected QT dispersions across the studies were statistically significantly higher in the patients with anxiety. Crude values of QT dispersion were available in 164 patients with anxiety and in 273 controls. Summarised standardised difference in the means (random effect model) was equal to 1.472 (95% CI: 1.034-1.911). Rate-corrected QT dispersion values were available in 193 patients with anxiety and in 282 controls, and the summarised standardised difference in the means was equal to 3.299 (95% CI: 1.215–5.384).
Conclusion: High anxiety is associated with increased QT dispersion, which may predispose to cardiac arrhythmias.
Fig. 32. 1. Meta-analysis: QT dispersion in patients with anxiety disorders