Conflict of Interest Declaration
The ILCOR Continuous Evidence Evaluation process is guided by a rigorous ILCOR Conflict of Interest policy. The following Task Force members and other authors were recused from the discussion as they declared a conflict of interest: none
The following Task Force members and other authors declared an intellectual conflict of interest and this was acknowledged and managed by the Task Force Chairs and Conflict of Interest committees: none
No Task Force members had any intellectual conflicts of interest to declare.
Task Force Synthesis Citation
Scquizzato T, Zelop C, Berg K, Drennan I, on behalf of the ILCOR Advanced Life Support Task Force. Transesophageal echocardiography during cardiopulmonary resuscitation for cardiac arrest. Available on ilcor.costr.org
Methodological Preamble and Link to Published Scoping Review
The continuous evidence evaluation process for the production of Consensus on Science with Treatment Recommendations (CoSTR) started with a scoping review conducted by the ILCOR ALS TF with involvement of clinical content experts. Evidence for adult literature was sought and considered by the Advanced Life Support Task Force.
Scoping Review
Webmaster to insert the Scoping Review citation and link to Pubmed using this format when/if it is available.
PCC (Population–Concept–Context)
Population:
Adults (≥ 18 years or as defined in individual studies) with cardiac arrest (in-hospital or out-of-hospital) undergoing cardiopulmonary resuscitation (CPR)
Concept:
The use of transesophageal echocardiography (TEE) during CPR.
Comparative and non-comparative evaluations are included:
- Comparative studies: Standard CPR without TEE (comparator may include transthoracic echocardiography [TTE] alongside standard CPR). Studies comparing TEE vs TTE and TEE vs no ultrasound will both be eligible and analyzed separately in a subgroup analysis.
- Non-comparative studies: No comparator (single-arm).
Outcomes of interest include:
- Critical outcomes: Survival with favorable neurologic outcome (at hospital discharge, 30 days or longer); survival (at hospital discharge, 30 days or longer); health-related quality of life
- Important outcomes: return of spontaneous circulation, identification of reversible causes of arrest, rhythm identification, any change in resuscitation management/intra-arrest treatments (e.g., chest compression location, additional procedures, termination of resuscitation), chest compression fraction, time to epinephrine, time to defibrillation, other CPR quality metrics, adverse events/complications related to TEE use.
Context
All clinical settings where CPR is performed: emergency departments, in-hospital environments (ICU, wards, procedural areas), pre-hospital systems, operating rooms or perioperative settings.
Randomized controlled trials (RCTs) and non-randomized studies (e.g., non-randomized controlled trials, interrupted time series, controlled before-and-after studies, cohort studies) are eligible for inclusion. Studies without a comparison group (e.g., cohort studies, case series) will also be included. Case reports, case series with less than 5 patients, trial protocols, editorials, commentaries, letters to the editor, and animal studies will be excluded. Studies involving TEE use only after ROSC will also be excluded.
All years and all languages are included as long as there is an English abstract
Search Strategies
We searched PubMed, Embase, Cochrane, and ClinicalTrials.gov for all entries from database inception to October 9, 2025. We also searched for grey literature published up to November 18, 2025.
Data tables: ALS 3609 Sc R TEE Table 1 ROSC Survival Neurological outcome; ALS 3609 Sc R TEE Table 2 CPR quality; ALS 3609 Sc R TEE Table 3 Findings; ALS 3609 Sc R TEE Table 4 impact docx; ALS 3609 Sc R TEE Table 5 Feasibility and safety
Task Force Insights
1. Why this topic was reviewed.
Transesophageal echocardiography (TEE) provides continuous, high-resolution imaging of cardiac structures without the need to interrupt chest compressions, offering the potential to optimize resuscitation efforts in real time.1
TEE may support the identification of reversible causes of cardiac arrest, confirm the presence or absence of cardiac motion, and guide optimal chest compressions.1,2 Compared to transthoracic echocardiography (TTE), TEE minimizes the interruptions to chest compressions that often occur during image acquisition with TTE.3–5 These advantages suggest that TEE may support improvements in the quality of cardiopulmonary resuscitation (CPR); however, evidence that this translate into improved patients outcomes is lacking. Routine use of TEE during resuscitation raises important considerations, including the need for operator expertise, procedural feasibility, potential delays in CPR, risks associated with probe insertion, and the associated costs of equipment, maintenance, and staff training.
Although multiple studies have investigated the use of TEE during CPR, the available evidence is heterogeneous and limited.6 This topic has not previously been reviewed by ILCOR.
2. Narrative summary of evidence identified
A total of 1,216 records were identified. After removal of 342 duplicates, 874 titles and abstracts were screened. Of these, 64 studies were assessed in full text for eligibility, and 44 were excluded, leaving 20 studies included in the final analysis. The included studies were published between 1997 and 2025. The included studies comprised a total of 1,247 adult patients with cardiac arrest. Study details, including number of patients, setting, comparison groups and outcomes, are included in the tables. Approximately 80% of included patients (n = 994) experienced OHCA. In mixed cohorts, the proportion of OHCA ranged from 42% to 91%. The remaining cases included in-hospital cardiac arrest (IHCA) or mixed cardiac arrest populations. Several studies specifically focused on OHCA populations, including subgroups treated with extracorporeal CPR.7,8 Two studies exclusively investigated intraoperative cardiac arrest occurring during elective non-cardiac surgical procedures.9,10
Study designs included one prospective observational multi-center study,11 six prospective observational single-center studies,12–17 twelve retrospective observational single-center studies,2,7–10,18–24 and one cluster randomized clinical trial (available only as a published conference abstract).25 Most studies (n = 15, 75%) evaluated intra-arrest TEE performed in patients with cardiac arrest in the emergency department, with 88% being OHCA patients transported with ongoing CPR.7,8,11–13,15–17,19–25 Prehospital intra-arrest TEE performed by EMS physicians was described in 3 studies (15%),2,14,18 while TEE for intraoperative cardiac arrest was evaluated in 2 studies (10%).9,10
Among the 20 included studies,2,7–25 the majority were single-arm investigations with no comparator group (n = 18, 90.0%).2,7–18,20–24 A comparator was included in 2 studies (10.0%).19,25 One cluster randomized clinical trial compared intra-arrest TEE with conventional resuscitation without TEE,25 while an observational study compared resuscitation with TEE vs TTE vs standard resuscitation without ultrasound.19
Survival
Four studies (Table 1) enrolling a total of 385 adult OHCA patients arriving to the emergency department (ED) with ongoing CPR reported survival outcomes: two reported survival to ICU discharge12,25 and two reported survival to hospital discharge.7,20
One cluster randomized clinical trial including 132 patients found no difference in survival to ICU discharge between the TEE-guided group and the conventional CPR group (30% vs 30%, OR = 1.00 [95% CI, 0.48-2.10]).25
In a prospective observational study of 76 patients who underwent an intra-arrest TEE at ED arrival, those in whom the aortic valve remained open during chest compressions, defined as the absence of aortic valve deformity or narrowing that could obstruct blood flow into the aortic root, had higher rates of survival to ICU discharge compared with those in whom the aortic valve appeared compressed (33% vs 8.1%, adjusted OR = 6.74 [95% CI, 1.59–29]).12 No patients with a compressed aortic valve survived to hospital discharge, whereas 5.1% of those with an uncompressed aortic valve did.12
One retrospective study including 158 patients who received an intra-arrest TEE at ED arrival found that none of the patients with significant findings on TEE and 5.9% of patients without TEE findings survived to hospital discharge.20
In another retrospective study including 19 adult OHCA patients who received intra-arrest TEE at ED arrival for extracorporeal CPR cannulation, 13% of those with left ventricular outflow tract opening during chest compressions survived to hospital discharge compared with 0.0% among patients in whom the left ventricular outflow tract appeared closed.7
No studies comparing TEE use to no TEE reported survival at hospital discharge/30 days, 6 months, 12 months, or longer follow-up.
Neurological outcome
Survival with favorable neurological outcome at hospital discharge or 30 days was reported in one cluster randomized clinical trial including 132 adult OHCA patients arriving to the ED with ongoing CPR and comparing TEE-guided resuscitation with conventional CPR without TEE.25 No patients in either group were discharged alive with a modified Rankin Scale score < 3.25
No studies reported survival with favorable neurological outcome at 6 months, 12 months, or longer.
Health-related quality of life
No studies reported health-related quality of life.
Return of spontaneous circulation
Four studies (Table 1) including a total of 385 adult OHCA patients arriving to the ED with ongoing CPR reported return of spontaneous circulation (ROSC).7,12,20,25
One cluster randomized clinical trial including 132 patients found that sustained ROSC was achieved in 44% of patients in the TEE-guided group and 39% in the group with no TEE (OR = 1.21 [95% CI, 0.60-2.41]).25
In a prospective observational study of 76 patients who underwent an intra-arrest TEE at ED arrival, those in whom the aortic valve remained open during chest compressions, defined as the absence of aortic valve deformity or narrowing that could obstruct blood flow into the aortic root, had higher rates of any ROSC (56% vs 32%, adjusted OR = 3.30 [95% CI, 1.10–9.88]) and sustained ROSC (54% vs 24%, adjusted OR = 4.72 [95% CI, 1.46–15]) compared with those in whom the aortic valve appeared compressed.12
One retrospective study including 158 patients who received an intra-arrest TEE at ED arrival found that 28% of the patients with significant findings on TEE and 40% of patients without TEE findings had ROSC (p=0.16).20
In another retrospective study including 19 adult OHCA patients who received intra-arrest TEE at ED arrival for extracorporeal CPR cannulation, 88% of those with left ventricular outflow tract opening during chest compressions achieved ROSC or return of electromechanical activity after establishment of extracorporeal support, compared with none of the patients in whom the left ventricular outflow tract appeared closed.7
CPR quality
Three studies enrolling a total of 118 adult OHCA patients arriving to the ED with ongoing CPR12,13,19 and 19 adult patients with IHCA in the ED13,19 and one study enrolling 10 adult OHCA patients with intra-arrest TEE performed in the pre-hospital setting14 reported CPR quality outcomes (Table 2).
End-tidal CO2
In a prospective observational study of 76 patients who underwent an intra-arrest TEE at ED arrival, there was no difference in minute-to-minute end-tidal CO2 levels and end-tidal CO2 at the 10 minutes post-ED arrival between those in whom the aortic valve remained open during chest compressions, defined as the absence of aortic valve deformity or narrowing that could obstruct blood flow into the aortic root, and those in whom the aortic valve appeared compressed (16 [IQR, 10-25] mmHg vs 14 [IQR, 3.8-37] mmHg, p=0.674).12
Hemodynamics
Patients in whom the aortic valve remained open had a higher initial mean arterial pressure (54 ± 28 mmHg vs 34 ± 20 mmHg, p=0.029) and diastolic blood pressure (33 ± 21 mmHg vs 12 ± 11 mmHg, p=0.002) compared with those in whom the aortic valve appeared compressed. A diastolic blood pressure > 20 mmHg at any time during CPR was also achieved more frequently in patients with an open valve (94% vs 33%, p<0.001).12
Interruptions in chest compressions
In one observational study including 10 adult OHCA patients, the average hands-off time during resuscitation was comparable between those who underwent intra-arrest TEE in the prehospital setting by emergency medical services physicians and a historical control group who did not receive intra-arrest TEE (10 ± 7% vs 9 ± 5%, p = 0.24).14
In one retrospective study including 25 adult cardiac arrest patients (88% OHCA), those who underwent intra-arrest TEE had shorter mean chest compression pause durations (7 ± 5 seconds) compared with those assessed using transthoracic echocardiography (18 ± 8 seconds) or manual pulse checks (10 ± 5 seconds).19
A prospective study including 36 adult patients with cardiac arrest (56% with OHCA) stated there were no instances in which TEE delayed, obstructed, or complicated the resuscitation procedure.13
Detailed results from each individual study are available in Table 2.
TEE findings
Appropriateness of chest compressions
Ten studies (Table 3) enrolling a total of 779 cardiac arrest patients (88% OHCA) with ongoing CPR evaluated the appropriateness of chest compressions location with intra-arrest TEE.2,7,8,11,12,14–17,25
The area of maximal compression was determined to be:
- Not at the left ventricle in 23-76% of patients in two prospective studies including a total of 194 patients who underwent an intra-arrest TEE at ED arrival15,25 and in 89% patients in a retrospective study including 19 adult OHCA patients who underwent an intra-arrest TEE in the pre-hospital setting by EMS physicians
- At the aorta/aortic valve in 49% of 76 adult OHCA patients12 and in 59% of 34 adult patients with cardiac arrest (82% OHCA)16 who underwent an intra-arrest TEE in the ED.
- At the left ventricular outflow tract/aortic root in 41-53% of patients in 3 studies 2,16,17
One study found that area of maximal compression was more frequently determined to be at the left ventricle in patients resuscitated with manual CPR (39%) versus those with mechanical CPR (30%) or those who were resuscitated alternating both types of CPR (11%).11
LVOT opening during mechanical CPR at hospital arrival was present in 42% of patients in one study,7 and aortic valve opening was observed in 22% of patients in another.14
Abnormal findings and suspected etiology of cardiac arrest
Ten studies (Table 3) including a total of 494 patients with cardiac arrest (81% OHCA) and ongoing CPR reported rates of abnormal findings,9,10,13,15,17,20–24 including pulmonary embolism in 4.5-25% of patients,9,10,13,20–24 right chamber dilation in 8.8-57%,15,17 aortic dissection in 5.6-48%,13,15,20,21,23,24 intracardiac thrombus in 4.7-23%,10,15,17,20–22 pericardial effusion or cardiac tamponade in 3.1-11%,10,15,20,21,23,24 and myocardial infarction or regional wall motion abnormalities in 5.6-50%.9,10,13,22,24 Other findings included ventricular dysfunction in 56%,13 right-to-left shunt in 22%,21 cardiac contusion in 2.8%,13 and papillary muscle rupture in 2.1%.24 In one study, fine ventricular fibrillation was visualized in 14% of patients, 50% of the cases with suspected asystole.17
Four studies reported the rates of suspected etiologies of cardiac arrest.10,17,20,24 In 3 studies including a total of 227 patients (91% OHCA), TEE identified the possible cause of cardiac arrest in 20-85% of patients.17,20,24 In one retrospective study including 22 patients with intraoperative cardiac arrest during elective non-cardiac surgery, TEE identified the possible etiology in 86% of patients.10
One study reported that TEE had a sensitivity of 93%, a specificity of 50%, and a positive predictive value of 87% for identifying the cause of cardiac arrest during CPR.24
Detailed results from each individual study are available in Table 3.
Impact on management of cardiac arrest
Three studies including a total of 476 cardiac arrest patients (76% OHCA) who underwent intra-arrest TEE in the ED,11,15,24 one study including 19 OHCA patients who received intra-arrest TEE in the prehospital setting,2 and one retrospective study including 22 patients with intraoperative cardiac arrest during elective non-cardiac surgery10 reported the impact of TEE on cardiac arrest management (Table 4).
TEE findings were reported to influence management or lead to changes in therapy in 31-48% of patients across the three ED-based studies including 476 cardiac arrest patients (76% OHCA).11,15,24 In one study, TEE findings were reported to led to termination of resuscitation in 12% of patients, thoracotomy in 3.5%, and thrombolysis in 1.8% of 62 adult OHCA patients with intra-arrest TEE in the ED.15 In one study including 22 patients with intraoperative cardiac arrest during elective non-cardiac surgery10, TEE findings were reported to aid in further management in 81% patients and to the implementation of specific surgical interventions in 55% of patients.10 Chest compression location (either manual or mechanical) was modified under TEE guidance in 23-76% of 579 patients (85% OHCA) included in 4 studies.2,11,15,25 In the prehospital OHCA study including 19 patients, TEE-guided repositioning of chest compressions resulted in adequate echocardiographic evidence of left ventricular compression in 76% of patients, with a median adjustment time of 3 minutes (IQR 2–4).2
Feasibility and safety
Eight studies including a total of 449 cardiac arrest patients (93% OHCA) with intra-arrest TEE performed in the ED12,13,15,17,21–23,25 and two studies including a total of 21 OHCA patients with intra-arrest TEE performed in the pre-hospital setting14,18 reported the feasibility and safety outcomes of intra-arrest TEE (Table 5).
Feasibility
Four studies reported that TEE was successfully performed in 80-100% of patients.14,15,17,25 In two studies including 382 cardiac arrest patients, difficult probe insertion or the need for more than one attempt occurred in 18-25% of cases.11,22 Two studies including 57 cardiac arrest patients reported that good-quality intra-arrest TEE images in the ED were obtained in all cases.13,17 Across three studies including 132 cardiac arrest patients, different providers had high agreement in TEE findings, with kappa values of 0.92-0.96 for anatomical image interpretation,12,23 and substantial inter-rater reliability for cardiac activity (kappa = 0.65).18
Safety
Complications from intra-arrest TEE were absent or rare across seven studies including 598 patients (80% OHCA).11,13,14,17,18,21,22 Of these, one study reported delayed upper gastrointestinal bleed in 13% of 16 adult patients with cardiac arrest.22
3. Narrative Reporting of the task force discussions
The Task Force identified multiple important gaps in the published literature and substantial limitations that affect the interpretation and generalizability of current evidence.
Only two studies compared patients who underwent intra-arrest TEE with those who received standard resuscitation (without TEE or with transthoracic echocardiography).19,25 Of these, only the EXECT-CPR cluster randomized clinical trial directly evaluated whether an approach incorporating intra-arrest TEE is superior to conventional CPR without ultrasound and reported patient-centered clinical outcomes.25 This trial, available only in abstract form, enrolled adults with nontraumatic OHCA transported to the ED with ongoing CPR and found no differences in ROSC, survival, or neurological outcome between TEE-guided CPR and standard CPR without TEE.25
The Task Force noted a complete absence of comparative studies evaluating several critical patient-centered outcomes: survival at hospital discharge/30 days, 6 months, 12 months, or longest available follow-up; survival with favorable neurological outcome beyond hospital discharge/30 days; and health-related quality of life at any time point. Evidence for other important outcomes was also sparse, as sustained ROSC was reported only in the EXECT-CPR trial.25
Most of the evidence base originate from single-center observational descriptions of TEE use during CPR, without a comparator group (e.g., standard resuscitation without TEE or transthoracic echocardiography). A major focus of these studies was the identification of the area of maximal compression and its relationship to outcomes such as survival and ROSC. Evidence consistently showed an association between chest compressions delivered over the left ventricular outflow tract, the aortic valve, or the aortic root and worse outcomes, suggesting that targeting compressions over the left ventricle or avoiding obstruction of forward flow may be beneficial. However, only a small subset of studies evaluated whether TEE-guided repositioning of compressions improved outcomes, and results were unclear. Notably, the EXECT-CPR trial found no difference in ROSC, survival, or neurological outcome between TEE-guided adjustment of compression location and standard CPR.25 The intervention, however, was performed only at ED arrival, likely too late to meaningfully influence outcomes, and might be more effective if implemented in the prehospital phase. In one small retrospective prehospital study, TEE-guided repositioning achieved adequate echocardiographic evidence of left ventricular compression in 76% of patients, but no improvement in outcomes was reported.2 Thus, although promising, the clinical effect of this approach remains uncertain.
Other outcomes (quality of CPR, impact on resuscitation management, and TEE diagnostic findings) were reported inconsistently and with high heterogeneity. TEE findings were reported with wide variability, likely reflecting differences in indications for use and case selection rather than true population-level frequencies. Only one study reported diagnostic accuracy metrics,24 and no study systematically evaluated the diagnostic accuracy of TEE during cardiac arrest or assessed the downstream impact of TEE-based diagnoses on patient-centered outcomes.
The Task Force also examined whether intra-arrest TEE is preferable to transthoracic echocardiography. A small retrospective study of 25 adult cardiac arrest patients (88% OHCA) compared the duration of chest compression pauses across modalities and found that intra-arrest TEE resulted in shorter pauses (7 ± 5 s) than transthoracic echocardiography (18 ± 8 s) or manual pulse checks (10 ± 5 s).19 These findings suggest that TEE may allow shorter interruptions and offer superior imaging quality to guide clinical decision-making. However, this should be confirmed in larger studies.
No study used standardized protocols for when or how intra-arrest TEE should be deployed, and no data were available regarding the learning curve, training requirements, or system-level feasibility necessary for widespread implementation.
The majority of available studies focused on OHCA patients transported to the ED with ongoing CPR. As a result, major knowledge gaps persist regarding the role of intra-arrest TEE in IHCA outside the ED (e.g., in the intensive care unit or in the operating room) and in prehospital care. Only two studies exclusively addressed intraoperative cardiac arrest,9,10 and three prehospital studies were identified,2,14,18 limiting conclusions in these settings.
Several studies explicitly noted that TEE was performed only when trained or expert operators were available, suggesting potential selection bias and limiting generalizability to systems with less TEE expertise. The very high rates of successful probe insertion, image acquisition, and low procedural complications reported in these studies may not be reproducible across all providers, clinical environments, or institutions.
We identified one ongoing trial. The TAPCAP trial (Application of Transesophageal Echocardiography in Pre-hospital Cardiac Arrest Patients - ClinicalTrials.gov ID NCT06672315),26 a cluster-randomized study expected to be completed in August 2027 with an estimated enrollment of 186 adults with non-traumatic OHCA. The trial is designed to evaluate the feasibility of implementing TEE in the pre-hospital setting to guide optimal chest compression positioning during mechanical CPR. Patients allocated to the intervention arm receive TEE-guided positioning of the mechanical compression device, whereas those in the control arm receive standard placement based on the nipple–sternum landmark. The primary outcome is the proportion of successfully ensuring LV compression during prehospital CPR, while secondary outcomes include ROSC, neurological outcome at hospital discharge, and end-tidal CO2 measurements.
Overall, the Task Force concluded that substantial knowledge gaps remain, particularly regarding the effectiveness of intra-arrest TEE on patient-centered outcomes, its feasibility and safety in routine practice, the optimal implementation strategies, and its role in prehospital and non-ED in-hospital cardiac arrest settings. Robust multicenter comparative studies, including randomized trials with longer-term outcomes, are needed to determine whether intra-arrest TEE offers meaningful benefits outside the highly specialized environments where it is currently used.
Knowledge Gaps
- Whether an approach incorporating intra-arrest TEE is superior to conventional CPR without ultrasound or to transthoracic echocardiography (TTE) in improving patient-centered outcomes.
- Whether routine use of intra-arrest TEE is feasible across different operators, clinical environments, and systems, and what level of training and competency is required.
- The optimal timing and circumstances during advanced life support for deploying intra-arrest TEE.
- The diagnostic accuracy of intra-arrest TEE and the clinical impact of TEE-identified findings on patient outcomes.
- The effect of TEE-guided chest compression adjustment on patient-centered outcomes
- The cost-effectiveness and resource implications of implementing intra-arrest TEE in different healthcare settings.
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