The aim of the present study was to investigate the potential role of matrix metalloproteinase‑7 (MMP‑7) and apoptosis‑associated genes [TIMP metallopeptidase inhibitor 2(TIMP‑2), BCL2 associated X, apoptosis regulator (BAX) and BCL2, apoptosis regulator (BCL‑2)] in the pathogenesis of atrial fibrillation (AF) in a Beagle dog model.