Acute ischemic stroke workup — when to order TEE vs TTE in cryptogenic stroke?

1 Answer

**Clinical Context & Diagnostic Yield:** In the workup of Embolic Stroke of Undetermined Source (ESUS), the choice between Transthoracic Echocardiography (TTE) and Transesophageal Echocardiography (TEE) is critical. While TTE is non-invasive and excellent for assessing ventricular function and large thrombi, it has significant limitations in visualizing the left atrial appendage (LAA), the interatrial septum, and the ascending aorta. **Evidence for TEE over TTE:** - **Left Atrial Appendage (LAA):** TEE is the gold standard for identifying LAA thrombi, which are a common source of cardioembolism, especially in paroxysmal atrial fibrillation that may be missed on short-term monitoring. - **Patent Foramen Ovale (PFO) & Atrial Septal Aneurysm (ASA):** TEE with bubble study is significantly more sensitive than TTE for detecting PFO and characterizing the shunt, which is vital for determining the necessity of PFO closure (per REDUCE and CLOSE trials). - **Aortic Arch Atheroma:** TEE can identify complex plaques (>4 mm or mobile components) in the aortic arch, which are independent risk factors for recurrent stroke. **When to Order TEE:** Per the AHA/ASA and ESO guidelines, TEE should be considered in: 1. Patients <60 years old with cryptogenic stroke (to look for PFO/ASA). 2. Patients where a high-risk cardioembolic source is suspected despite a negative TTE. 3. Patients where the results of the TEE would change management (e.g., transitioning from antiplatelet to anticoagulation, or considering PFO closure). **Conclusion:** In this 67-year-old patient, if the suspicion for a cardioembolic source remains high despite a negative TTE and 48h Holter, TEE is indicated to evaluate for LAA thrombus or aortic arch atheroma, as these would mandate a shift to anticoagulation. *This information is for clinical discussion among peers and does not replace institutional protocols or formal medical advice.*