This study compares the effectiveness of pulsed field ablation (PFA) and thermal ablation (using radiofrequency or cryotherapy) in treating atrial fibrillation (AF). The ADVENT trial, a randomized controlled study, aimed to evaluate the safety and efficacy of PFA compared to thermal ablation. Key findings include: 1. **Pulmonary Vein Narrowing**: Thermal ablation is associated with a higher incidence of pulmonary vein narrowing (PVPN) compared to PFA. PVPN can lead to symptoms such as dyspnea, cough, and hemoptysis, and can progress over time. 2. **Non-Thermal Energy**: PFA uses high-voltage electric fields to cause irreversible electroporation, which does not lead to microvascular obstruction or intramural hemorrhage seen with thermal ablation. This results in less chronic fibrosis and preserved tissue compliance, reducing the risk of PVPN. 3. **Clinical Outcomes**: The ADVENT trial demonstrated that PFA was non-inferior to thermal ablation in terms of procedural success and safety at one year. However, PFA showed superiority in reducing PVPN at three months, with a significant reduction in the aggregate cross-sectional area of pulmonary veins. 4. **Mechanism of Action**: PFA's non-thermal mechanism of action, which involves irreversible electroporation, leads to less fibrosis and better tissue compliance compared to thermal ablation. This is supported by histopathological and clinical studies. 5. **Clinical Implications**: The absence of PVPN with PFA has significant implications for patients with heart failure or pulmonary hypertension, as even mild-moderate PVPN can lead to increased vascular resistance and symptoms. 6. **Limitations**: The study had limitations, including the lack of a protocol-mandated workflow for the thermal arm and the single-time-point follow-up. However, the results highlight the potential advantages of PFA in reducing PVPN and improving long-term outcomes. 7. **Conclusion**: PFA demonstrated a statistically significant reduction in PVPN compared to thermal ablation, emphasizing its favorable impact on pulmonary vein tissue and clinical outcomes. The study underscores the potential benefits of PFA in reducing complications associated with thermal ablation, particularly PVPN, and suggests that it may be a preferred option for treating AF.This study compares the effectiveness of pulsed field ablation (PFA) and thermal ablation (using radiofrequency or cryotherapy) in treating atrial fibrillation (AF). The ADVENT trial, a randomized controlled study, aimed to evaluate the safety and efficacy of PFA compared to thermal ablation. Key findings include: 1. **Pulmonary Vein Narrowing**: Thermal ablation is associated with a higher incidence of pulmonary vein narrowing (PVPN) compared to PFA. PVPN can lead to symptoms such as dyspnea, cough, and hemoptysis, and can progress over time. 2. **Non-Thermal Energy**: PFA uses high-voltage electric fields to cause irreversible electroporation, which does not lead to microvascular obstruction or intramural hemorrhage seen with thermal ablation. This results in less chronic fibrosis and preserved tissue compliance, reducing the risk of PVPN. 3. **Clinical Outcomes**: The ADVENT trial demonstrated that PFA was non-inferior to thermal ablation in terms of procedural success and safety at one year. However, PFA showed superiority in reducing PVPN at three months, with a significant reduction in the aggregate cross-sectional area of pulmonary veins. 4. **Mechanism of Action**: PFA's non-thermal mechanism of action, which involves irreversible electroporation, leads to less fibrosis and better tissue compliance compared to thermal ablation. This is supported by histopathological and clinical studies. 5. **Clinical Implications**: The absence of PVPN with PFA has significant implications for patients with heart failure or pulmonary hypertension, as even mild-moderate PVPN can lead to increased vascular resistance and symptoms. 6. **Limitations**: The study had limitations, including the lack of a protocol-mandated workflow for the thermal arm and the single-time-point follow-up. However, the results highlight the potential advantages of PFA in reducing PVPN and improving long-term outcomes. 7. **Conclusion**: PFA demonstrated a statistically significant reduction in PVPN compared to thermal ablation, emphasizing its favorable impact on pulmonary vein tissue and clinical outcomes. The study underscores the potential benefits of PFA in reducing complications associated with thermal ablation, particularly PVPN, and suggests that it may be a preferred option for treating AF.