Related Experiment Video
Updated: Sep 12, 2026

Recapitulation of an Ion Channel IV Curve Using Frequency Components
Published on: February 8, 2011
Curvature effects on activation speed and repolarization in an ionic model of cardiac myocytes
1Institute of Biomedical Engineering, Université de Montréal and Research Centre, Hôpital du Sacré-Coeur, 5400 Gouin West Blvd, Montréal, Québec, Canada H4J 1C5.
Abstract:
Reentry is a major mechanism underlying the initiation and perpetuation of many cardiac arrhythmias. Stimulated ventricular myocytes give action potential characterized by a fast upstroke, a long-lasting plateau, and a late repolarization phase. The plateau phase determines the action potential duration (APD) during which the system remains refractory, a property essential to the synchronization of the heart cycle. The APD varies much with prematurity and this change has been shown to be the main determinant of the dynamics in models of paced cells and cable, and during reentry in the one-dimensional loop. Curvature has also been shown to be an important factor for propagation in experimental and theoretical cardiac extended tissue. The objective of this paper is to combine both curvature and prematurity effects in a kinematical model of propagation in cardiac tissue. First, an approximation of the ionic model is used to obtain the effects of curvature and prematurity on the speed of propagation, the APD, and the absolute refractory period. Two versions of the ionic model are studied that differ in their rate of excitability recovery. The functions are used in a kinematical model describing the propagation of period-1 solutions around an annulus.
More Related Videos
07:42Contractions of Human-iPSC-derived Cardiomyocyte Syncytia Measured with a Ca-sensitive Fluorescent Dye in Temperature-controlled 384-well Plates
Published on: October 18, 2018
08:44Dynamic Clamp Methods to Investigate Impaired Neuronal Excitability Associated with Autism
Published on: October 17, 2025
Related Concept Videos
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
G-Protein Gated Ion Channels
Sensory organs,...
Generation of Action Potential in Skeletal Muscles
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Action Potential: Phases of Stimulation
Resting Phase:
In this phase, the cell's membrane is at its resting potential, typically around -70 millivolts (mV) for neurons. Inside the cell, there is a higher concentration of potassium ions (K+) and a lower concentration of sodium ions (Na+). Voltage-gated sodium channels are closed, and...
Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials