Increased P Wave Dispersion and Maximum P Wave Duration after Hemodialysis

Abstract

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.