Quantitative histological assessment of atrial fibrillation-associated fibrosis in animal models: a systematic review.

Atrial fibrillation (AF) is the most common sustained arrhythmia and cardiac fibrosis is a major component in driving its progressive nature. Quantitative histological assessment of fibrosis in animal models is crucial for understanding AF, but current published studies present various methodologies that limit comparison. This systematic review examines 195 AF studies across multiple animal models (mice, rats, goats, dogs, pigs and horses) to summarize: 1) quantified fibrosis results, 2) methodologies for histological fibrosis assessment and 3) evaluate anti-fibrotic therapies used in these studies.