| Theme |
Electrolyte and acid-base disorders in dialysis patients |
| Title |
Mathematical analysis for the impact of calcium dynamics on cardiac beating in hemodialysis treatment |
| Author |
Hiroyuki Hamada |
Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University |
| Author |
Akihiro C. Yamashita |
Department of Chemical Science and Technology, Faculty of Bioscience and Applied Chemistry, Hosei University |
| [ Summary ] |
We developed a novel mathematical analysis tool based on clinical engineering and electrophysiology and evaluated the impact of Ca2+ dynamics on cardiomyocyte beating in hemodialysis treatment, for which the Ca2+ concentration in plasma was higher than that in the dialysis fluid. The developed tool can be used to estimate the beating rhythm of the central sinoatrial nodal cell and the contraction force in cardiac ventricular cells. A decline of the Ca2+ concentration in the plasma and interstitial fluid in the hemodialysis treatment decreased the total circulation amount of Ca2+ in cardiomyocytes, resulting in both transient slowing of the beating rate and weak contraction force. We also explored the mechanism for the decrease in circulating Ca2+ through a microscopic assay of ion currents through ion channels. The mathematical analysis revealed that an activation of a Na/Ca exchanger during the treatment leads to a decrease in the total amount of Ca2+ in cardiomyocytes, resulting in a functional disorder of cardiomyocyte beating. In the case where the Ca2+ concentration in the plasma is higher than that in the dialysis fluid, an increase in the Ca2+ concentration in the dialysis fluid rescues the declining function of the beating cardiomyocytes. |