QTc dispersion increases during hemodialysis with low-calcium dialysate

S E Näppi, V K Virtanen, H H Saha, J T Mustonen, A I Pasternack
Kidney International 2000, 57 (5): 2117-22

BACKGROUND: The risk of ventricular arrhythmias is known to increase during hemodialysis (HD) treatment, but the cause of this phenomenon has remained unidentified. QT dispersion (= QTmax - QTmin) reflects heterogeneity of cardiac repolarization, and increased dispersion is known to predispose the heart to ventricular arrhythmias and sudden cardiac death.

METHODS: We studied the effect of dialysate calcium concentration on cardiac electrical stability during HD treatment in 23 end-stage renal disease patients. Three HD treatments were applied with dialysate Ca++ concentrations of 1.25 mmol/L (dCa++1.25), 1.5 mmol/L (dCa++1.5), and 1.75 mmol/L (dCa++1.75). The QTc interval and QTc dispersion were measured before and after the three sessions.

RESULTS: With the dCa++1.5 and dCa++1.75 dialyses, serum Ca++ increased and the QTc interval remained stable (dCa++1.5) or decreased (dCa++1.75), but no significant change was noted in QTc dispersion. With dCa++1.25 HD, serum Ca++ decreased (1.24 +/- 0.11 vs. 1.20 +/- 0.09 mmol/L, P < 0. 05), and both the QTc interval (403 +/- 27 vs. 419 +/- 33 ms, P < 0. 05) and QTc dispersion increased (38 +/- 19 vs. 49 +/- 18 ms, P < 0. 05). The change in the QTc interval correlated inversely with the change in serum Ca++ (r = -0.68, P < 0.0001). Except for serum Ca++ and plasma intact parathyroid hormone, predialysis and postdialysis values in other blood chemistry, blood pressure, heart rate, body weight, and total ultrafiltration were equal in the three dialysis sessions.

CONCLUSION: This study is the first, to our knowledge, to demonstrate that HD increases QTc dispersion if a low-calcium (dCa++1.25) dialysate is used. This indicates that the use of low-calcium dialysate may predispose HD patients to ventricular arrhythmias and that perhaps it should be avoided, at least when treating patients with pre-existing cardiac disease.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Trending Papers

Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"