Introduction. Electrocardiographic changes are frequently observed in patients undergoing hemodialysis. Prolonged QTc interval, increased QTc dispersion and deranged capability to adapt QTc interval to heart rate have been reported during HD and may cause arrhythmias. Serum concentrations of potassium (K) and calcium (Ca) influence ionic currents and the duration of ventricular action potential. The concentration of K and Ca in dialysate strongly influences the concentration gradient between both sides of dialysis membrane and ultimately changes blood composition in patients. The combination of low K and Ca concentration in the dialysate has been associated with longest value of QTc interval and with elevated risk of life-threatening arrhythmias. Moreover, blood pH may influence blood concentration of ions and for this reason it is reasonable to hypothesize that pH of dialysate may cause changes of QTc during and/or after HD. The aim of the present study is to assess the potential relationship between different concentrations of bicarbonate, Ca, and K in dialysate with changes of QTc during and after HD. Methods. The study was performed in 22 patients with different electrolyte and bicarbonate concentrations in dialysate. Tested dialysate concentrations were: potassium = 2 and 3 mmol/L; calcium=1.25, 1.5, and 1.75 mmol/L; bicarbonate= 30, and 34 mmol/L. ECG was recorded one hour before, at the end, and every hour throughout four hours after study dialysis session. QTc interval was measured from the beginning of the QRS complex to the end of a T wave on a 12-lead ECG. Blood was collected and K, total Ca, ionic Ca and pH evaluated. Results. At the end of study hemodialysis session with dialysate containing low K (2 mmol/L), low Ca (1.25 mmol/L), and high bicarbonate concentration (34 mmol), mean QTc interval was significantly prolonged compared to that recorded with dialysate containing high K (3 mmol/L), high Ca (1.75 mmol/L), and bicarbonate (30 mmol) (40±10 ms Vs 2±2 ms; p<0.01). Dialysate with low concentration of low Ca, K, and high concentration of bicarbonate resulted as independent predictor of QTc; the combination of low Ca and K, and high bicarbonate strongly increased the risk of prolonged QTc interval. Conclusion. The present pilot study shows that changes in QTc interval during hemodialysis depend on both electrolyte and bicarbonate concentrations in
EFFECT OF DIFFERENT DIALYSATE CONCENTRATIONS ON QTc INTERVAL IN PATIENTS ON CHRONIC MAINTENANCE HEMODIALYSIS / Torraca, S.; Sirico, M. L.; Di Micco, L.; Piscopo, C.; Berardino, L.; Morrone, L. F.; Russo, Domenico; Di Iorio, B.. - In: GIORNALE ITALIANO DI NEFROLOGIA. - ISSN 1724-5990. - (2011). (Intervento presentato al convegno 52° Congresso Nazionale della Società Italiana di Nefrologia. Genova, 21-24 Settembre 2011 tenutosi a Genova, nel 21-24 Settembre 2011).
EFFECT OF DIFFERENT DIALYSATE CONCENTRATIONS ON QTc INTERVAL IN PATIENTS ON CHRONIC MAINTENANCE HEMODIALYSIS
RUSSO, DOMENICO;
2011
Abstract
Introduction. Electrocardiographic changes are frequently observed in patients undergoing hemodialysis. Prolonged QTc interval, increased QTc dispersion and deranged capability to adapt QTc interval to heart rate have been reported during HD and may cause arrhythmias. Serum concentrations of potassium (K) and calcium (Ca) influence ionic currents and the duration of ventricular action potential. The concentration of K and Ca in dialysate strongly influences the concentration gradient between both sides of dialysis membrane and ultimately changes blood composition in patients. The combination of low K and Ca concentration in the dialysate has been associated with longest value of QTc interval and with elevated risk of life-threatening arrhythmias. Moreover, blood pH may influence blood concentration of ions and for this reason it is reasonable to hypothesize that pH of dialysate may cause changes of QTc during and/or after HD. The aim of the present study is to assess the potential relationship between different concentrations of bicarbonate, Ca, and K in dialysate with changes of QTc during and after HD. Methods. The study was performed in 22 patients with different electrolyte and bicarbonate concentrations in dialysate. Tested dialysate concentrations were: potassium = 2 and 3 mmol/L; calcium=1.25, 1.5, and 1.75 mmol/L; bicarbonate= 30, and 34 mmol/L. ECG was recorded one hour before, at the end, and every hour throughout four hours after study dialysis session. QTc interval was measured from the beginning of the QRS complex to the end of a T wave on a 12-lead ECG. Blood was collected and K, total Ca, ionic Ca and pH evaluated. Results. At the end of study hemodialysis session with dialysate containing low K (2 mmol/L), low Ca (1.25 mmol/L), and high bicarbonate concentration (34 mmol), mean QTc interval was significantly prolonged compared to that recorded with dialysate containing high K (3 mmol/L), high Ca (1.75 mmol/L), and bicarbonate (30 mmol) (40±10 ms Vs 2±2 ms; p<0.01). Dialysate with low concentration of low Ca, K, and high concentration of bicarbonate resulted as independent predictor of QTc; the combination of low Ca and K, and high bicarbonate strongly increased the risk of prolonged QTc interval. Conclusion. The present pilot study shows that changes in QTc interval during hemodialysis depend on both electrolyte and bicarbonate concentrations inI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
