Percentage of fibrosis
We calculated a surrogate of fibrosis studying the percentage of LVA
with 0.5 mV threshold. This percentage was calculated as the
relationship between the area with voltage <0.5mV and the
total area. We analysed it in both maps (AF and SR). In a newly created
qualitative variable to assess fibrosis, we assigned a value of 1 when
the percentage of LVA was greater than 5%.