QT dispersion in the surface electrocardiogram in elderly patients with major depression

Background: QT dispersion (QTd) is a measure of interlead variations of QT interval of the surface 12-lead electrocardiogram (ECG). Increased QTd, fou nd in various cardiac diseases, reflects cardiac instability and is associa ted with increased cardiac death. Major depressive disorder (MDD) was found to be associated with high cardiovascular mortality rates. This study comp ares QTd in elderly patients with MDD to normal controls. Methods: QTd and rate-corrected QTd of 18 physically healthy elderly patients (69.9+/-7.6 ye ars) with MDD was compared to nine physically and mentally healthy age- and gender-matched controls (64.1+/-12.2 years). Results: QTd and rate-correct ed QTd were significantly higher in MDD compared to controls (68+/-30 vs. 4 0+/-13 ms, P = 0.002 and 81+/-39 vs. 43+/-13 ms, P = 0.001, respectively). Intra-and inter- observer reproducibilities were highly correlated (r = 0.9 6, P < 0.0001; r = 0.88, P < 0.001, respectively). Limitations and Conclusi ons: The major limitations of this study are the small number of subjects a nd the fact that all the patients were maintained on antidepressant medicat ion. However, if, seems that QTd analysis might shed light on possible auto nomic imbalance and also provide a novel cardiovascular risk factor for inc reased cardiac death in MDD. (C) 2000 Elsevier Science B.V. All rights rese rved.