Transesophageal echocardiography in cardiac arrest: why, how, when, and where in clinical practice.

Transesophageal echocardiography (TEE) has emerged as a transformative tool in the management of cardiac arrest, offering significant advantages over traditional transthoracic echocardiography (TTE) by enabling continuous, high-resolution cardiac imaging during resuscitation. Initially used in operating rooms before 2000, TEE expanded into emergency departments (EDs), intensive care units (ICUs), and even prehospital settings. Its superior imaging capability during cardiopulmonary resuscitation (CPR) supports rapid diagnosis, optimization of compression quality, and more accurate rhythm assessment, including the differentiation between asystole and fine ventricular fibrillation. TEE has been shown to influence intra-arrest clinical decision-making in up to 78% of cases, often revealing pathologies-such as aortic dissection or cardiac rupture-not detected by TTE. Importantly, TEE aids in identifying reversible causes of cardiac arrest, guiding high-quality CPR by assessing left ventricular outflow tract (LVOT) obstruction, and shortening the duration of pulse checks. It also may play a role in extracorporeal CPR (ECPR) and organ donation procedures, particularly in cannulation and monitoring during extracorporeal membrane oxygenation (ECMO) and normothermic regional perfusion (NRP). TEE use is feasible and safe during cardiac arrest, with high insertion success rates and minimal complications when performed by trained personnel. While cardiologists, anesthesiologists, and intensivists traditionally perform TEE, simplified training protocols now enable emergency physicians to safely and effectively deploy TEE in critical settings. Protocols such as "POCUS-TEE" may promote rapid acquisition of essential views, facilitating broader implementation. Despite the potential benefits, several barriers to widespread adoption remain. These include the availability of equipment, limitations in training, and concerns regarding the safety of the probe during defibrillation. Resuscitation guidelines recommend removing the transesophageal echocardiogram (TEE) probe, or at least insulating it, as a precaution during defibrillation. TEE is particularly valuable when TTE proves inadequate, such as in obese or mechanically ventilated patients. In conclusion, TEE might enhance the quality and precision of resuscitation in cardiac arrest and has the potential to improve survival and neurological outcomes in selected cases. Its broader adoption hinges on institutional support, streamlined protocols, operator training, and further research to validate its impact on patient-centered outcomes. As technology advances and clinical integration improves, TEE may become a cornerstone of advanced life support in both in-hospital and out-of-hospital settings.