Fig. 2

Atrial fibrillation mouse model establishment. A Surface electrocardiogram of each group of mice, and the sequence from top to bottom was adult control (Group A), adult AF (Group B), aged control (Group C), and aged AF (Group D). The ECG of Group B and Group D mice showed the atrial fibrillation waveform. B Left atrial area detected by M-mode echocardiogram, and the sequence from left to right was Group A-D. Yellow dashed lines encircle the left atrium. C, D Representative images of Masson's trichrome staining of the atrial area and measurements of the fibrosis area, and the sequence from left to right was Group A–D (n = 5 in each group), *P < 0.05; **P < 0.01. E Heart gross specimens and the sequence from left to right was Group A–D. Yellow dashed lines encircle the left atrium