Impact of the Right Atrium on Arrhythmia Vulnerability

Atrial fibrillation (AF) is one of the most common cardiac diseases. However, a complete understanding of how
to treat patients suffering from AF is still not achieved. As the isolation of the pulmonary veins in the left atrium (LA)
is the standard treatment for AF, the role of the right atrium (RA) in AF is rarely considered. We investigated the impact
of including the RA on arrhythmia vulnerability in silico. We generated a dataset of five mono-atrial (LA) and five bi-atrial
models with three different electrophysiological (EP) setups each, regarding different states of AF-induced remodelling.
For every model, a pacing protocol was run to induce reentries from a set of stimulation points. The average share of inducing points across all EP setups was 0.0, 0.8 and 6.7 % for the mono-atrial scenario, 0.5, 27.3 and 37.9 % for the bi-
atrial scenario. The increase in inducibility of LA stimulation points from mono- to bi-atrial scenario was 0.91 ± 2.03%,
34.55 ± 14.9 % and 44.2 ± 14.9 %, respectively. In this study, the RA had a marked impact on the results of the vulnerability assessment that needs to be further investigated.