Factors Affecting QT Dispersion During Hemodialysis in End-Stage Renal Disease Patients

AIM: To investigate the situation of the cardiac arrhythmia in the cases within the chronic haemodialysis program and its pathogenesis.

MATERIALS and METHOD: Sixty-four patients who admitted to the department of nephrology in our hospital with chronic renal failure requiring haemodialysis were taken into our study. In order to determine and asses the QT dispersion before and after haemodialysis, conventional ECG records with 12 derivations were taken.

RESULTS: Pre-haemodialysis QT and QTc dispersion were calculated as 49.6 ± 24 msn and 57 ± 29 msn; post-haemodialysis QT and QTc dispersion were calculated as 75 ± 33 msn and 93 ± 38 msn, reflecting significant changes (p<0.001). Of the electrolyte values taken before and after haemodialysis, K⁺ was shown to have a significant change (p<0.001). Positive correlation was observed between the decrease in K⁺ and the increase in QT dispersion (p<0.05). Negative correlation was observed between the QT dispersion increase and the amount of ultrafiltration (p<0.05).

DISCUSSION: QT and QTc dispersion increases were affected by the decrease in K⁺ value and the amount of ultrafiltration that occurred during haemodialysis. This indicates that the gradual reduction in K⁺ and optimization of ultrafiltration levels will increase the threshold of arrhythmia being one of the causes of cardiac mortality.