Title :
Post-repolarization refractoriness in human ventricular cardiac cells
Author :
Rodriguez, JF ; Heidenreich, EA ; Romero, L. ; Ferrero, JM, Jr. ; Doblare, M.
Author_Institution :
GEMM, Univ. de Zaragoza, Zaragoza
Abstract :
Computer simulations have been used to study the mechanisms of postrepolarization refractoriness in cardiac cells under ischemic conditions at the cellular level. The ten Tusscher model of the cardiac action potential has been used with the formulation of the ATP-sensitive K+ current by Ferrero et al being adopted. Cells were subjected to hyperkalemia, hypoxic and acidic conditions. The results show that the three components of ischemia decrease the action potential duration (APD) as well as the conduction velocity, while effective refractory period (ERP) depicts a non-monotonic behavior. Under hyperkalemic conditions, no supernormal conduction is observed near physiologic values, and conduction relies on ICa(L) for [K+]o > 11 mmol/L. Under hypoxic conditions the trend observed in hyperkalemia are maintained but conduction blocking is obtained at a [K+]o concentration of 10 mmol/L. This condition minimally affects the conduction velocity of the hyperkalemic tissue. Acidosis gradually increases the difference between ERP and APD for reductions above the 60%, with conduction blocking occuring at 90%.
Keywords :
biochemistry; bioelectric potentials; biomembrane transport; cardiology; cellular biophysics; digital simulation; diseases; medical computing; potassium; Tusscher model; acidic condition; acidosis; action potential duration; cardiac action potential; computer simulation; conduction blocking; effective refractory period; human ventricular cardiac cells; hyperkalemia; hypoxic condition; ischemic conditions; nonmonotonic behavior; post-repolarization refractoriness; Biomembranes; Calcium; Cells (biology); Computer simulation; Enterprise resource planning; Extracellular; Humans; Ischemic pain; Myocardium; Velocity measurement;
Conference_Titel :
Computers in Cardiology, 2008
Conference_Location :
Bologna
Print_ISBN :
978-1-4244-3706-1
DOI :
10.1109/CIC.2008.4749108