Increased QT dispersion in the absence of QT prolongation in patients with Behcetʹs disease and ventricular arrhythmias

In Behcetʹs disease, prominent clinical manifestations include involvement of mucocutaneous, ocular, gastrointestinal, respiratory, neurologic, urogenital, articular and cardiovascular systems. Patients with Behcetʹs disease have higher incidence of ventricular arrhythmia than healthy subjects. However there is a little information about the mechanism of ventricular arrhythmias in Behcetʹs disease. The aim of the study was to investigate whether dispersion of ventricular repolarisation was an arrhythmogenic mechanism. QT dispersion parameters were measured in 73 Behcet patients and QT dispersion was defined as the difference between the maximum and minimum QT interval in any of the 12 leads of surface electrocardiogram. Corrected QT dispersion for heart rate was calculated by Bazettʹs formula. The results were compared with the data from 51 matched controls without a history of cardiac disease. We found QT dispersion was greater in Behcet patients (58±12 vs. 37±8 ms, P=0.001) as was corrected QT dispersion (81±14 vs. 52±11 ms, P=0.001). There was no significant difference in minimum or maximum QT intervals between Behcet patients and controls (P>0.05). We found a correlation between QT dispersion and grade of premature ventricular complexes (r=0.7, P=0.002). Our findings suggest that increased dispersion of repolarisation may account for the development of ventricular arrhythmias in Behcetʹs disease.