Pre-ablation imaging protocol for LAA thrombus evaluation
In the pre-COVID cohort, pre-procedural TEE was performed routinely for all the patients presenting in AF or atrial flutter (AFL) on the day of ablation, and ablation was conducted after LAA thrombus was ruled out. CT scans in the pre-COVID cohort were not analyzed for the presence or absence of LAA thrombus but were used solely for assistance in electroanatomical mapping during the ablation itself. In the post-COVID cohort, we implemented a cardiac CT-based protocol for LAA thrombus evaluation, with TEE used selectively only in patients with findings suggestive of LAA thrombus on CT imaging. All patients underwent CT imaging with first- and second-pass image acquisition to assess for LAA thrombus. TEE imaging was triggered only in patients with positive CT scan findings. If CT imaging was negative, or if triggered TEE imaging was negative, patients underwent ablation as planned. If triggered TEE was positive for LAA thrombus, the ablation procedure was canceled.