The combination of pulmonary vein electrophysiology and atrial fibrosis determines driver location

Patients exhibit a range of pulmonary vein (PV) and fibrosis properties, but their individual and combined effects on arrhythmia inducibility and maintenance mechanisms is unknown. We aim to predict locations of high phase singularity (PS) density using a combination of PV electro-physiology and fibrosis measurements. We used a bilayer computational human atrial model with interstitial fibrosis based on delayed-enhancement MRI (DE-MRI), including high or low levels of fibrosis. PV action potential duration and conduction velocity were varied. Reentry was observed around the left atrial (LA)-PV junction in a subset of patients and reproduced in the model for PV properties with baseline APD, but not for short. For patients for whom rotors were located away from the PVs, increasing model fibrosis from low to high increased the model agreement with clinical PS density 2.3 ± 1.0 fold. For other patients, lower levels of fibrosis with baseline PV properties were more appropriate. These results suggest that modelling both PV electrophysiology and atrial fibrosis is important for determining arrhythmia mechanisms. The combined use of PV and DE-MRI measurements may improve ablation therapy success.