ANNALS OF NONINVASIVE ELECTROCARDIOLOGY

Background: Atrial fibrillation is a frequent arrhythmia in patients undergoing hemodialysis. The consequences of hemodialysis on P wave durations and P wave dispersion have not been fully understood. The objective of this study was to study the effect of dialysis on P wave maximum (P-max), P wave minimum (P-min), and P wave dispersion (P-d). Methods: We studied P-max, P-min, and P-d in 32 patients (17 men and 15 women, mean age 54 +/- 18 years) with chronic renal failure undergoing hemodialysis. The difference between maximum and minimum P wave duration was calculated and defined as P wave dispersion (P-d = P-max - P-min). Results: There was a significant increase in P-max at the end of dialysis compared to the beginning (98 +/- 13 ms vs. 125 +/- 12 ms, P < 0.001). P-min did not show any significant change (71 +/- 11 ms vs. 73 +/- 10 ms, P = 0.42). P-d was significantly increased at the end of dialysis (27 +/- 9 ms vs. 52 +/- 11 ms, P < 0.001). There was a negative correlation between serum potassium, magnesium, phosphate, blood urea nitrogen, and creatinin at the end of dialysis and P-max and P-d. respectively (P < 0.05). A weak positive correlation was found between serum calcium, bicarbonate at the end of dialysis and P-max and P-d (P < 0.05). Conclusion: Hemodialysis ends with significant increase in P wave maximum duration and P wave dispersion, which might be responsible for the increased occurrence of atrial fibrillation in these groups of patients