01Purpose and principlesWhat the assessment is for and the core concepts behind it.
Select the modality from the question. TTE is accessible and haemodynamically informative; TOE is preferred when TTE windows are inadequate or detailed views of vegetations, prosthetic valves, left atrial appendage, interatrial septum or thoracic aorta are needed.
A useful report states rhythm, blood pressure when relevant, image quality, chamber size, systolic and diastolic function, regional wall motion, valve morphology and severity, right-heart findings, aorta, pericardium and comparison with prior studies.
Unexpected critical findings require direct clinician-to-clinician communication, not passive report filing.
Key points
- TTE is first-line for ventricular size and function, valve assessment, pulmonary-pressure estimates and pericardial fluid.
- TOE places the probe near posterior cardiac structures and gives higher-resolution views of atria, valves and thoracic aorta.
- A focused bedside echo answers a narrow emergency question; it is not a substitute for a complete accredited study.
- Ejection fraction is load-dependent and should be integrated with volumes, regional motion and clinical state.
- Valve severity requires multiple concordant parameters; never grade from colour-jet area alone.
- TOE is semi-invasive: confirm consent, fasting status, airway and oesophageal risks, sedation plan and monitoring.
- Negative imaging does not end a high-probability endocarditis or aortic-dissection work-up; repeat or alternative imaging may be required.
02Indications, selection and cautionsWhen it is useful, when urgency changes and important limitations.
Pericardial effusion with right-sided chamber collapse, marked respiratory inflow variation and a plethoric IVC supports haemodynamic compromise; clinical shock determines urgency.
New severe mitral regurgitation, ventricular septal defect or free-wall rupture with instability demands immediate cardiology and surgical escalation.
Integrate morphology, velocities, gradients, valve area, regurgitant measures, chamber response and symptoms; discordant data need expert review.
Vegetation, abscess, prosthetic dehiscence or new regurgitation is important, but a negative TTE is insufficient when clinical suspicion remains high.
RV dilatation or dysfunction and raised pulmonary-pressure estimates support pressure overload but do not diagnose pulmonary embolism in isolation.
03Method and interpretationA systematic approach to the test and its findings.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Comprehensive TTEFirst stepFirst line - Why
- First-line structural and haemodynamic assessment.
- Interpretation and limitations
- Use quantitative multiparametric reporting and state limitations; compare with previous measurements using the same method where possible.
- 02
Focused emergency TTE - Why
- Rapidly assess ventricular function, major pericardial effusion and gross volume clues in instability.
- Interpretation and limitations
- Treat it as a time-limited question and obtain comprehensive imaging after stabilisation.
- 03
TOE - Why
- Resolve prosthetic-valve, endocarditis, left atrial appendage, septal or thoracic-aortic questions.
- Interpretation and limitations
- Superior resolution does not remove sampling limitations; repeat imaging when disease evolves and suspicion persists.
- 04
Contrast echocardiography - Why
- Improve endocardial-border definition or identify selected shunts and masses.
- Interpretation and limitations
- Use an approved agent or agitated saline for the correct indication with trained monitoring; protocols are not interchangeable.
- 05
CMR or cardiac CT - Why
- Resolve poor acoustic windows, tissue-characterisation questions or anatomy not fully shown by echo.
- Interpretation and limitations
- Choose the complementary modality based on rhythm, device, renal function, radiation and the clinical question.
04Clinical next stepsHow the result changes management or prompts escalation.
01Preferred routeNew murmur or suspected heart failureFirst stepPreferredSymptoms, signs, ECG or natriuretic peptide suggest structural disease+
- 1Request comprehensive TTE with a specific clinical question and relevant prior information.
- 2Grade any lesion using multiple measures and relate it to ventricular response and symptoms.
- 3Refer moderate or severe valve disease, ventricular dysfunction or pulmonary hypertension through the appropriate specialist pathway.
- 4Set surveillance from the lesion and guideline, not an arbitrary annual default.
02AlternativeWhen TOE adds valueAlternativeTTE is non-diagnostic or detailed posterior, prosthetic, embolic-source or aortic imaging is needed+
- 1Confirm that TOE will change management and review prior imaging.
- 2Screen for swallowing difficulty, oesophageal disease, bleeding risk, dentition, airway and sedation risk; obtain consent.
- 3Perform with continuous monitoring and a trained recovery pathway.
- 4Document findings, complications and post-sedation restrictions; arrange complementary CT or CMR if unresolved.
03EscalationUnstable patientEscalationShock, acute pulmonary oedema, new post-MI murmur or suspected tamponade+
- 1Resuscitate and obtain immediate expert focused imaging at the bedside where it will change action.
- 2EscalationEscalate tamponade or mechanical-complication findings directly to intervention or surgery.
- 3If images are inadequate, choose TOE, CT or catheterisation according to the emergency and stability.
- 4Repeat a full study after intervention or when haemodynamics change.
05Risks, monitoring and follow-upComplications, safety checks and further assessment.
- Record heart rate, rhythm and blood pressure when interpreting Doppler measurements.
- Use lesion-specific echo surveillance intervals and bring review forward for new symptoms.
- During TOE monitor oxygen saturation, blood pressure, ECG, airway and sedation depth, then use formal recovery criteria.
- Track ventricular size and function with consistent methods across serial studies.
- Communicate critical findings directly and document receipt.
06Special situationsVariants, exceptions and circumstances that change the usual approach.
EF is not contractility
Preload, afterload, valve lesions and geometry can change ejection fraction without a matching change in intrinsic myocardial function.
Low-flow valve states
A low gradient does not exclude severe aortic stenosis when stroke volume is low; reconcile valve area, flow and ventricular function.
TOE sees posterior structures
The left atrial appendage, mitral apparatus and prosthetic valves are common reasons it outperforms transthoracic windows.
Tamponade is clinical
Echo signs support physiology, but drainage decisions depend on haemodynamic compromise, cause and trajectory.
Report the limitation
An explicit 'apex not visualised' is safer than a falsely normal regional-wall-motion statement.
07Common pitfallsFrequent interpretation and management errors.
- 01
Equating a visually estimated ejection fraction with a precise, load-independent measurement.
- 02
Grading regurgitation from colour area alone.
- 03
Calling endocarditis excluded after one negative TTE in a high-risk presentation.
- 04
Performing sedated TOE without documented airway, oesophageal and recovery assessment.
- 05
Letting a focused bedside scan replace a complete study after stabilisation.