Related Experiment Video
Updated: Aug 15, 2026

Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
Published on: July 3, 2013
Acute effects of amiodarone on sodium currents in isolated neonatal ventricular myocytes: comparison with
F Chen1, G T Wetzel, T S Klitzner
1Department of Pediatrics, University of California at Los Angeles, School of Medicine 90024.
Abstract:
Recent studies suggest that amiodarone's acute clinical effects in infants and children are related predominantly to its class I antiarrhythmic activity. However, the effects of amiodarone on Na+ currents have not been investigated directly in immature cardiac cells. Accordingly, the tight seal whole cell voltage clamp technique was used to measure time- and voltage-dependent Na+ currents in acutely isolated neonatal ventricular myocytes from 2- to 5-day-old rabbits, before and after addition of amiodarone (0.1-10 microM). To evaluate the class I antiarrhythmic activity of amiodarone in this age group, the effects of amiodarone on Na+ currents were compared with those of procainamide. Similar to procainamide, amiodarone significantly decreased peak inward Na+ current in neonatal ventricular myocytes. Moreover, both amiodarone and procainamide shifted the steady-state inactivation curve to more negative membrane potentials and delayed recovery of the Na+ current from inactivation. Thus, the effects of amiodarone on the Na+ current in immature myocardium are qualitatively similar to those of procainamide, suggesting that amiodarone may act acutely as a class I antiarrhythmic agent in the newborn heart.
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
08:11Voltage-Dependent Potassium Current Recording on H9c2 Cardiomyocytes via the Whole-Cell Patch-Clamp Technique
Published on: November 11, 2022
Related Concept Videos
Electrophysiology of Normal Cardiac Rhythm
Antiarrhythmic Drugs: Class I Agents as Sodium Channel Blockers
Class 1A Antiarrhythmic Drugs: These drugs work by moderately blocking sodium channels,...
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers
Antiarrhythmic Drugs: Class IV Agents as Calcium Channel Blockers
Verapamil, a calcium channel blocker, inhibits calcium movement across myocardial cell membranes and vascular smooth muscle. This results in the dilation of coronary and...
Antiepileptic Drugs: Sodium Channel Blockers
Sodium channel blockers modulate ion channels, particularly voltage-gated sodium channels. They block only sodium ion movement.
Among the most commonly prescribed antiepileptic drugs are...
Antiepileptic Drugs: Potassium Channel Activators
Ezogabine has gained approval as an adjunctive treatment...