QT dispersion estimated from 80 body surface potential map leads and from standard 12-leads ECG in psychiatric patients treated with dosulepin.

The aim of the study was to detect changes of the QT dispersion (QTd) due to cardiotoxicity of tricyclic antidepressant dosulepin. Electrocardiographic and body surface potential mapping (BSPM) recordings were obtained using Cardiag 112.2 diagnostic system from 27 psychiatric outpatients treated with prophylactic doses of dosulepin and compared to those obtained from 37 healthy volunteers. From these recordings the QTd and the dispersion of heart rate-corrected QT interval QTc were evaluated. These parameters were estimated both from 80 BSPM leads and from 12 standard ECG leads. Acquired data were statistically correlated by Spearman rank order correlation coefficient with dosulepin plasma levels. The average QTd evaluated from BSPM leads (+/-SD) in the dosulepin group was significantly higher [70 (+/-21) ms] than that in the control group [34 (+/-12) ms] (P< 0.001). Moreover, the correlation between QTd and the dosulepin plasma level was statistically significant as well (P< 0.001) with the value of correlation coefficient 0.7871. The QTd evaluated from standard 12 ECG leads was increased in dosulepin group as well [46 (+/-18) ms vs. 28 (+/-10) ms - P< 0.05] but we have not found any significant correlation of the QTd with the dosulepin plasma level. According to the above-mentioned results we can conclude that the QTd estimated from BSPM leads (but not that estimated from 12-lead ECG) could be used as a marker of the dosulepin effect on the myocardium.