Preparation of a chronic complete atrioventricular block rat model using myocardial surface radiofrequency ablation.

Research using rat models of chronic complete atrioventricular block (CAVB) remains limited, and several problems, particularly model instability, persist. This study aimed to optimize the method used to establish a CAVB rat model. The most suitable approach for establishing a CAVB rat model was selected from chemical ablation, myocardial invasive radiofrequency ablation, and myocardial surface radiofrequency ablation by comparing their success rates and stability. The findings indicate that myocardial surface radiofrequency ablation using a thin blunt tip is a reliable method for establishing a CAVB rat model, offering a high success rate, operational simplicity, and good stability. Moreover, myocardial surface radiofrequency ablation with a thin blunt tip achieved comparable success rates under two different parameter settings (20 W/5 s and 25 W/3 s). An appropriately sized contact tip should be selected to prevent accidental contact with the aorta. The ablation parameters can be adjusted according to the principle that lower power requires a longer ablation duration, whereas higher power permits a shorter duration. This CAVB rat model is important for further investigating the mechanisms underlying CAVB and developing more effective therapeutic interventions.