Background Cardiac arrhythmias, such fibrillation and tachycardias, are marked by disrupted electrical conduction and exacerbated interstitial fibrosis. This study aims to characterize the histological remodeling of rabbit heart tissue during induced arrhythmias. Four New Zealand White rabbits (3–4 kg) were divided into control (n=1) and experimental (n=3) groups. Isolated hearts were subjected to Langendorff perfusion. Arrhythmias were induced using 1 µM carbachol and S1-S2 protocol (100 bursts of 2 ms pulses at 1.3 s intervals) to trigger atrial tachycardia and ventricular fibrillation. After electrophysiological study, hearts were fixed in formalin, and tissue samples were collected from four defined atrial and ventricular regions. From each region, three slices (each with 3–6 sections, 5 µm thick) were prepared. Hematoxylin and eosin (H&E) staining assessed general tissue integrity, and histological parameters of the remodeling. Quantitative image analysis (ImageJ) compared structural differences between groups. Results Control group showed that hearts had preserved tissue architecture. In contrast, hearts that underwent arrhythmia exhibited increased interstitial fibrosis and cardiomyocyte hypertrophy, more pronounced in ventricular fibrillation, indicating significant cellular stress and structural remodeling. Conclusion This study identifies distinct structural alterations associated with atrial and ventricular arrhythmias in rabbit hearts. The ongoing study will compare cardiac tissue characterization with the heart electrical activity underneath mapped simultaneously with panoramic optical and epicardial electrical contact mapping.