What is the primary lesion set for AF ablation?

• A. Electrical isolation of the pulmonary veins and substrate modification.
• B. Right atrial appendage ablation.
• C. Isolating the superior vena cava.
• D. Ventricular pacing from the left ventricle.

Answer: (A)

The main idea is that eliminating the pulmonary vein triggers is central to AF ablation. In most patients with atrial fibrillation, ectopic activity from the pulmonary veins enters the left atrium and drives the arrhythmia. The standard approach is to create circumferential lesions around the openings of the pulmonary veins to electrically isolate them from the left atrium, effectively preventing those triggers from initiating or sustaining AF. Substrate modification, adding additional lines or targets to address atrial remodeling, may be used in persistent or difficult cases, but the foundational lesion is pulmonary vein isolation. The other options don’t address the primary trigger pathway: ablating the right atrial appendage, isolating the superior vena cava, or pacing from the left ventricle do not constitute the core strategy for AF ablation.