Purpose of review Although the overall mortality rate of patients with end-stage renal disease in the United States continues to decline, cardiac complications remain a leading cause of death in this population. The purpose of this review is to identify principles that can be used to optimize the dialysate concentration of electrolytes in order to reduce the incidence of sudden cardiac deaths (SCDs). Recent findings The ratio of observed to expected SCD is 1.71 in the 12 h following the onset of a hemodialysis session. A dialysate potassium concentration of less than 2 mEq/l has been associated with an increased risk of SCD as has a dialysate calcium less than 2.5 mEq/l and an elevated serum to dialysate calcium gradient. Midweek predialysis serum bicarbonate concentrations that are less than 22 or more than 27 mEq/l have been associated with increased mortality. An elevated predialysis serum bicarbonate may be a sign of the malnutrition inflammation complex syndrome. Magnesium has not been well studied in hemodialysis patients. Summary Dialysate content plays an important role in the risk of SCD in hemodialysis patients on hemodialysis. There is a need for further studies designed to identify patients at risk and to determine what strategies can be used to lower this risk.