Related Experiment Video
Updated: Jun 26, 2026

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples
Published on: April 21, 2014
Ionic current abnormalities associated with prolonged action potentials in cardiomyocytes from diseased human right
Gui-Rong Li1, Chu-Pak Lau, Tack-Ki Leung
1Department of Medicine and Institute of Cardiovascular Science and Medicine, Faculty of Medicine, The University of Hong Kong, China. grli@hkucc.hku.hk
Objectives:
This study was designed to determine whether ionic currents in right ventricular myocytes from explanted human transplant recipient hearts are related to right ventricular histopathology and function.
Background:
Cardiac action potential duration (APD) is prolonged in ventricular tissues/cells from patients with heart failure, but the ionic mechanisms are not well documented.
Methods:
Membrane currents and transmembrane action potentials in myocytes from right ventricular epicardium of explanted human hearts were recorded using whole-cell patch clamp technique. Data from cells from right ventricles with severe histologic and functional abnormalities (abnormal histology group [AH]) and from right ventricles with preserved histology and function (relatively normal histology group [RNH]) were compared.
Results:
We found that APD at 50% (APD(50)) and 90% repolarization (APD(90)) were significantly longer in AH cells than in RNH cells. Early afterdepolarizations (EADs) were observed in 20% of AH cells and none of the RNH cells. Inwardly rectifying K(+) current (I(K1)) was decreased (both inward and outward components). Both transient outward K(+) current (I(to1)) and slowly delayed rectifier K(+) current (I(Ks)) were down-regulated in AH cells. L-type Ca(2+) (I(Ca.L)) was not altered in AH cells.
Conclusions:
I(K1), I(to1), and I(Ks) are down-regulated in AH cells of human heart failure. This down-regulation contributes to APD prolongation that favors the occurrence of arrhythmogenic EADs and suggests a link between human cardiac histopathologic/functional abnormalities and arrhythmogenic ionic remodeling.
More Related Videos
09:35Preclinical Cardiac Electrophysiology Assessment by Dual Voltage and Calcium Optical Mapping of Human Organotypic Cardiac Slices
Published on: June 16, 2020
08:39Single-Cell Optical Action Potential Measurement in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes
Published on: December 22, 2020
Related Concept Videos
Electrophysiology of Normal Cardiac Rhythm
Mechanism of Cardiac Arrhythmias
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
Cardiomyopathy II: Dilated Cardiomyopathy
Cardiomyopathy III: Hypertrophic Cardiomyopathy
ECG Interpretation of Arrhythmias II: Atrial, Junctional and Ventricular Arrhythmias