Mechanisms underlying pro-arrhythmic abnormalities arising from Pitx2-induced electrical remodelling: an in silico...

Area of Science:

• Cardiology
• Computational Biology
• Molecular Biology

Background:

• Electrical remodeling, driven by Pitx2 gene regulation, underlies atrial fibrillation (AF) mechanisms.
• Pitx2 plays a key role in the gene expression that alters cardiac electrical properties.

Purpose of the Study:

• To identify specific ionic current changes induced by Pitx2.
• To understand how these changes lead to action potential (AP) shortening and triggered activity in AF.

Main Methods:

• Developed computational atrial AP models from patient data (SR and AF).
• Categorized AF models into triggered, untriggered, shortened, and unshortened groups.
• Analyzed the impact of Pitx2-regulated ion currents on AP characteristics.

Main Results:

• Selected 2,885 SR and 4,781 AF models from 30,000.
• AF models replicated experimental findings of AP shortening and triggered activity.
• Variability in IKr and IKs modulated AP duration, while ICaL and SERCA influenced AP morphology and triggered activity.

Conclusions:

• Pitx2 upregulation is linked to increased shortened AP incidence.
• Pitx2 downregulation may promote triggered activity, contributing to AF genesis.