Episodes of T-Wave and QRS Complex Alternans in Haemodialysis Patients

Objective: To detect occurrence of T-wave and QRS alternans, to evaluate their independent predictors, and to estimate alternans change during haemodialysis (HD). Methods: We studied 58 patients, mean age 59 ± 13 years, 52% males. We performed 1-minute ECG-recording before and after HD determining episodes of alternans. Results: T-wave alternans episodes were present in 21% and 28% of patients pre-HD and post-HD, respectively, without significant change during the procedure. Pre-HD values were independently predicted by body mass index (BMI) (negative correlation) and number of cigarettes smoked (positive correlation). Post-HD values were predicted by usage of acetyl salicylic acid (ASA) and ferric substitutes (negative correlation) and baseline heart rate (positive correlation). Episodes of QRS alternans were evident in 7 patients pre-HD and one post-HD: significant decrease during HD (from 0.26 ± 0.85 to 0.07 ± 0.53 number of alternans episodes, p = 0.015). Independent predictors for baseline QRS alternans values were BMI and ASA usage (negative correlation), baseline heart rate and calcium channel blocker usage (positive correlation). Conclusion: Both T-wave and QRS alternans are present in HD-patients. T-wave alternans episodes did not change significantly during HD-procedure, while episodes of QRS alternans showed significant decrease. Regression analysis suggested protective effects for higher BMI and ASA usage in this group.