Background: High-power radiofrequency ablation (HP-RFA) is a minimally invasive technique for treating atrial fibrillation (AF); pulmonary vein isolation (PVI) serves as the cornerstone of this treatment. Variations in patient characteristics, such as body mass index (BMI), can influence the effectiveness and safety of PVI procedures. Obesity is a growing concern, and its impact on cardiac interventions remains an area of ongoing research.
Methods: We developed virtual patient models from CT scans by performing detailed segmentation, incorporating anatomical structures such as the heart, lungs, liver, fat, and muscle. We used three virtual patients, one for each of the following BMI groups: normal weight (<25 kg/m²), pre-obesity (25–30 kg/m²), and morbid obesity (>35 kg/m²), as shown in Figure 1A. Electrodes were placed at four locations on the left atrial wall near the pulmonary veins, as in Figure 1B. A dispersive patch at the back of each virtual patient completed the circuit. The power distribution in the ablation procedure was simulated using a high-power protocol set at 90 W.
Results: The virtual patient models showed significant BMI-related variations in anatomical structures, especially fat and muscle distribution, which impacted power delivery. In morbidly obese patients, increased fat tissue caused higher impedance. Despite these variations, small differences were observed in the dissipated power within the left atrial tissue. All patients showed consistently higher tissue power dissipation for thicker tissues, particularly at the right superior pulmonary vein. However, this trend was only observed per patient, as obese patients feature lower tissue power dissipation than normal weight ones for the same wall thickness.
Discussion: Our study demonstrates the feasibility of using computational modeling to analyze how BMI affects PVI. These insights highlight the potential for personalized strategies to improve the effectiveness and safety of cardiac interventions.