QT dispersion as a predictor of arrhythmic events in patients with ankylosing spondylitis

Objective. The aim of the study was to evaluate QT dispersion (QTd), an ind icator of repolarization heterogeneity, and its relation to ventricular arr hythmias in patients with ankylosing spondylitis (AS). Methods. A full history, clinical examination, electrocardiograms and 24-h Holter monitoring were performed in 88 AS patients and 31 volunteers of sim ilar age and sex. Groups were compared based on electrocardiographic abnorm ality, QTd, arrhythmias and heart blocks. Results. QTd and corrected QTd (QTcd) were significantly greater in AS pati ents than controls (QTd, 52.8 +/- 15.1 vs 35.5 +/- 8.9 ms, P < 0.0001; QTcd , 60.3 +/- 16.1 vs 39.4 +/- 10.7 ms, P < 0.0001). The magnitudes of these p arameters were associated with the duration of the disease (QTd, r = 0.56, P < 0.01; QTcd, r = 0.60, P < 0.001). The frequency of ventricular extrasys toles was found to be correlated with QTd (r = 0.35, P < 0.01) and QTcd (r = 0.33, P < 0.01). Conclusion. Involvement of the heart may be seen in AS during the early cli nical course of the disease. QTd may give clues about the presence of arrhy thmias and can be used as a new technique for the evaluation of asymptomati c patients. Earlier detection of cardiac involvement could alter the progno sis of the patients.