The factors associated with arrhythmia during dialysis course in maintained hemodialysis patients

Background Cardiovascular mortality and morbidity are high in maintained hemodialysis patients. Arrhythmia is known to predispose to sudden cardiac death. This study was conducted to assess the occurrence of arrhythmia during dialysis course and analyze the factors of arrhythmia in these patients. Methods Two hundred and seventy-nine maintained hemodialysis patients were assessed by standard examination including heart rate, 12-lead electrocardiography and laboratory tests like electrolytes (Na (+), K (+), Ca (++), phosphate), urea, and creatinine, uric acid, blood glucose at beginning, 2h, ending of HD. The PR intervals, QRS duration and QT intervals for each lead were measured manually by one observer using calipers. Patients with arrhythmia pre-dialysis were excluded. And follow up the patients' prognosis outcomes. Results Arrhythmia was found in 92 patients in the dialysis session. Univariate analysis of the determinants of arrhythmia showed a direct relation with male (P = 0.004), old people (P = 0.000), longer dialysis duration, lower systolic blood pressure before dialysis (P = 0.013), lower diastolic blood pressure in the whole dialysis session (P < 0.05), longer PR interval (P = 0.000), longer QRSd interval (P < 0.05), longer corrected QT interval (QTc) during dialysis (P = 0.018), lower total calcium concentration (P = 0.033) and lower blood glucose concentration (p = 0.016)post-dialysis. The multivariate linear regression model showed that the only independent predictors of arrhythmia were gender (P = 0.001), age (P = 0.000), PR interval > 160mms post-dialysis and QRSd interval post-dialysis (P = 0.000 and p = 0.049 respectively). Followed up to 10 years, 197 patients died and 82 patients alive. The variables associated with all-cause mortality in the Cox model were Heart Failure (HF) (HR,2.4; 95% CI, 1.32 to 4.37), coronary heart disease (CHD) (HR,2.78; 95% CI, 1.82to4.24), diabetes (HR, 2.40; 95% CI, 1.69to 3.41), and QTc during dialysis ≥ 470ms (HR, 1.57; 95% CI, 1.14to 2.17). Conclusion Male, old people, patients with PR interval and QRS duration prolongation after dialysis were correlated with attack of arrhythmia in maintained hemodialysis patients. Among patients with HF, diabetes, CHD, QTc during dialysis ≥ 470ms were associated with a substantially increased risk for mortality (all-cause, cardiovascular, and arrhythmic).