@tanyawic An ablation damages tissues. It 'cauterizes' endothelial tissue lining the left atrium in the case of AF. Damaged tissues release cytokines which cause inflammation. Inflamed and damaged tissues are roughened and will have stuff flowing adjacent to them stick to them, things like blood cells and platelets. Platelets cause clots.

You WANT an anticoagulant issued to you with instructions to take it for at least three months post ablation. If a Watchman were implanted in the LAA at the same time, or later, you would WANT a DOAC to take for close to a year or until the confirmatory TEE shows no leakage.