Evaluation of the Frequency of QTc Dispersion and Its Relationship with Clinical and Laboratory Parameters in Dialysis Patients

OBJECTIVE: QTc dispersion is defi ned as the difference between the maximal and minimal correct QT interval on standard 12-lead ECG. Increased QTc dispersion has been reported in ESRD patients. In our study, we aimed to evaluate the frequency of QTc dispersion and its relationship between clinical and laboratory parameters in patients on regular dialysis programme.

MATERIAL and METHODS: Sixty patients underwent dialysis (30 HD, 30 CAPD) and another 30 healthy subjects were enrolled into the study. The standard 12 lead ECGs were performed and QTcd was measured from all dialysis patients and control subjects. Blood samples were collected for the measurement of laboratory parameters.

RESULTS: Dialysis patients showed signifi cantly higher QTcd than control subjects (55.75±36.48 versus 28.73±28.27; p=0.001). Patients with QTcd >50 ms had signifi cantly higher SBP, urea and ferritin levels, but signifi cantly lower iron binding capacity and calcium levels compared those with QTcd ≤ 50 ms(p<0.05). Positive correlations were found between QTcd and urea, ferritin and SBP levels, and inverse correlations with iron binding capacity level (p<0.05).

CONCLUSION: The frequency of QTc dispersion was 40% among the dialysis patients .Although serum calcium was signifi cantly lower in patients who had QTcd >50 ms than QTcd ≤ 50 ms (p<0.05), there was no signifi cant correlation between QTcd and calcium.