1. Chen et. al. (2021) showed Fgf21 administration effectively suppressed atrial remodeling by reducing oxidative stress, which provides a novel therapeutic insight for AF.
The electrical mapping with pen-MEA and the optical mapping were used to assess electrical conduction in ex vivo heart preparations. The optical mapping further showed the APD90 was prolonged in both left and right atria of AngII mice.

https://www.frontiersin.org/articles/10.3389/fcvm.2021.720581/full

2. Zou et. al. (2021) showed a cardiac specific G protein (Gi) overexpression in young guinea pigs predisposed the heart to ventricular tachyarrhythmias.
The optical mapping was used to assess arrhythmic tendency in ex vivo heart preparations.
In summary, the authors reported that bAR activation induces an acute reduction in cardiac IKs in aging guinea pig hearts through the b2AR-Gi signaling pathway, which contributes to increased susceptibility to arrhythmogenesis in aging hearts.

https://www.heartrhythmjournal.com/article/S1547-5271(21)02124-X/fulltext