Background: The present study is to estimate the geometrical and constituent heterogeneity effects on electrical conduction on in vitro monolayer consisting of atrial-like cardiomyocytes (ALCMs) derived from human induced pluripotent stem cells (hiPSCs) and human atrial fibroblasts (HAFbs) under HF field stimuli (HFFS).
Method: We induced hiPSCs into ALCMs by adding all-trans retinoic acid (ATRA). The ALCMs and HAFbs were transferred in defined ratios on manually fabricated plate with geometrical transition. HFFS were delivered, and the electrical propagation was assessed by optical mapping.
Results: ATRA-treated CMs showed atrial specific properties compared to untreated CMs. HFFS preferentially induced impaired conduction on ALCMs with an abrupt geometrical transition, but not on ALCMs with uniform geometry. In addition, the co-culture of HAFbs with the ALCMs deteriorated the stability of electrical conduction than in mono-culture of ALCMs.
Conclusion: Geometrical heterogeneity under HFFS jeopardizes electrical conduction on in vitro ALCMs monolayer. Constituent heterogeneity represented by HAFbs contributes to the deterioration of the electrical conduction stability.