Effect of Hemodialysis on Corrected QT Interval and QTc Dispersion

Area of Science:

• Cardiology
• Nephrology
• Clinical Electrophysiology

Background:

• Patients with chronic kidney disease (CKD) undergoing hemodialysis face elevated cardiovascular disease risks.
• Traditional and dialysis-specific factors contribute to these risks, necessitating investigation into cardiac electrophysiology during treatment.

Purpose of the Study:

• To investigate the impact of hemodialysis on the corrected QT interval (QTc) and QTc dispersion in CKD patients without pre-existing heart conditions.
• To assess changes in serum electrolytes (potassium, calcium, magnesium) and their correlation with QTc parameters post-hemodialysis.

Main Methods:

• A study involving 200 CKD patients on chronic intermittent hemodialysis (>3 months).
• Electrocardiography (12-lead) and serum electrolyte levels (creatinine, potassium, calcium, magnesium) were measured before and after hemodialysis sessions.
• Statistical analysis was performed to compare pre- and post-dialysis values and correlate findings with QTc parameters.

Main Results:

• A significant increase in mean QTc interval (433.4 to 451.4 ms, p=0.001) and QTc dispersion (60.5 to 81.5 ms, p=0.001) was observed after hemodialysis.
• Prolonged QTc interval and dispersion were noted in a high percentage of patients post-hemodialysis (50% and 89%, respectively).
• Significant post-hemodialysis changes included decreased serum potassium (p=0.001) and increased serum calcium (p=0.001), with no change in magnesium (p=0.424).

Conclusions:

• Hemodialysis leads to significant prolongation of QTc interval and QTc dispersion in CKD patients.
• Electrolyte shifts during hemodialysis, particularly decreased potassium and increased calcium, are associated with altered cardiac repolarization and increased QTc dispersion.