Balance Between Rapid Delayed Rectifier K⁺ Current and Late Na⁺ Current on Ventricular Repolarization: An Effective Antiarrhythmic Target?

ABSTRACT:

Background

Rapid delayed rectifier K⁺ current (I_Kr) and late Na⁺ current (I_NaL) significantly shape the cardiac action potential (AP). Changes in their magnitudes can cause either long or short QT syndromes associated with malignant ventricular arrhythmias and sudden cardiac death.

Methods

Physiological self AP-clamp was used to measure I_NaL and I_Kr during the AP in rabbit and porcine ventricular cardiomyocytes to test our hypothesis that the balance between I_Kr and I_NaL affects repolarization stability in health and disease conditions.

Results

We found comparable amount of net charge carried by I_Kr and I_NaL during the physiological AP, suggesting that outward

SUBMITTER: Hegyi B 

PROVIDER: S-EPMC7331791 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature