Fig. 5

Fibrosis quantification. (A) Representative images of Picro Sirius red staining and comparison of collagen content in the left atrium (LA), the right atrium (RA) and the left ventricle (LV) between controls (CTR) and horses with atrial fibrillation (AF) (Student’s t-test). (B) representative images from wheat germ agglutinin (WGA) labelling and comparison of WGA intensity in the LA, the RA and the LV between CTR and horses with AF (Student’s t-test), * p < 0.05). Representative examples of Picro Sirius red are shown from control horse 13 (mare, 5 years, 405 kg) and from AF horse 6 (stallion, 3 years, weight unknown) for RA and LV and from AF horse 8 (mare, 3 years, 402 kg) for LA. For WGA, representatives are shown from control horse 14 (gelding, 6 years, 500 kg) for LA and LV and from control horse 10 (gelding, 7 years, 490) for RA and from AF horse 5 (gelding, 2 years, 410 kg).