QT interval variability in familial Mediterranean fever: a study in colchicine-responsive and colchicine-resistant patients

The association between familial Mediterranean fever (FMF), early atherosclerosis, and electrocardiographic markers for arrhythmias remains controversial. There are conflicting results as to the occurrence of high QT dispersion in FMF. The aim of the present study was to further investigate repolarization dynamics and other repolarization-associated pro-arrhythmogenic markers in FMF patients. To explore repolarization in FMF, patients who responded well to colchicine and patients who had not responded to colchicine, yet were amyloidosis-free, were included. We aimed to evaluate whether increased inflammatory burden, a characteristic of non-responsive patients, was specifically associated with abnormal repolarization. Included in the study were 53 FMF patients (27 colchicine non-responders) and 53 age- and sex-matched control subjects. Electrocardiograms were performed under strict standards. QT variability parameters were computed with custom-made computer software. No significant difference in any of the QT dynamic parameters was found in either FMF group compared with the healthy controls. Mean values of QT variability index, regardless of colchicine response, were similar to previously published results for healthy persons. In conclusion, patients with FMF who are continuously treated with colchicine and have not developed amyloidosis, regardless of their clinical response, have normal QT variability parameters, indicating normal repolarization dynamics and suggesting no increased risk of repolarization-associated cardiac arrhythmias.