Introduction to Trans-oesophageal Echocardiography

TEE
5-10% of echocardiography studies.
In IJN, around 200 cases (2003) to >1000 cases (2007)
Knowledge of appropriate indications, contraindications and risks of TEE.
Knowledge of the physical principles of echocardiographic image formation, cardiac anatomy and alterations and blood flow velocity measurement.
Knowledge of adequate data, adequate or inadequate TEE examination.

TEE

Physician should be assisted by an experience sonographer, to make sure optimum image acquisition and to ensure patients safety.
Nearest crash trolley.
Oxygen outlet and suction facility available.
Pulse oximeter should be available.
Obtain baseline vital signs.
Check indications for procedure.
Patient consent.
Inspection of probe, mobility of the probe tip, full flexion/extension and right/left flexion

TEE
Fasted for at least 4 hrs prior to the procedure.
Explain in brief the procedure, inform to expect mild abdominal discomfort and gagging sensation with probe advancement.
Trolley ( IV supplies, N/saline, 3-way tap, gloves.
20G IV cannula.
Dentures and eye-glasses to be removed.
Lidocaine spray (must cover posterior pharynx and tongue).
Warn not to eat or drink for at least 1 hr after local anaesthesia.

TEE
Help in patient positioning (left lateral decubitus)
Bite guard (must).
Reassure patient through-out procedure.

TEE
Check-list:
Swallowing problems, haematemesis.
Liver disease (varices).
Low oxygen saturation.
Allergy to latex.

TEE
Complication:
Hypoxia (0.6%)
Hypotension (0.5%)
PSVT,NSVT (0.2%)
Haematemesis (0.1%)
Oesophageal tear (<0.02%)>

TEE
Probe insertion (oesophageal intubation)
Nausea is common (just pause and leave the probe alone)
Start imaging in the oesophagus then the gastric views. GE junction is usually around 40 cm.

TEE
Image Format:
Right sided structures are on the left and left sided on the right.
Apex of the imaging plane with the electronic artefact is at the top of the screen.

TEE
Mid-oesophageal view (LAA & LPV).
Push down – LVOT.
Swing across to look at IAS.
Swing across to look at RPV.
Swing back , push probe in to get 4 chamber view.
Change angle to around 40 degrees (aortic valve en-face).
Look at septum, TV, RVOT and PV.
Change angle to around 60-90 degrees (MV).
Rotate probe to et bi-caval view.
Change angle to 110%.
Go trans-gastric.

LVH

PLAX 2D .... LVH

MMODE ..... SAM

CW DOPPLER ....DAGGER SHAPE

HYPERTROPHIC CARDIOMYOPATHY IN ECHO

DEFINITION:

Hypertrophied
Non-dilated left ventricle (LV)
Absence of another cardiac or systemic disease

HCM

Autosomal dominant with incomplete penetrance.
Most common inheritable cardiovascular disease (0.1-0.2% in general population).

HCM - PRESENTATION

36 year old gentleman presented to general/ CV clinic with a history of shortness of breath (usually with exertion).
Dizziness, presyncope/syncope, AF ?cause, family history of sudden death, atypical chest pain and heart failure symptoms.
Look at the ECG: LVH with strain, deep T wave inversion.

HCM - Differential

Noonan’s, LEOPARD, Friedrich ataxia
RV hypertrophy, D-TGA Athletes heart, hypertension, AS
Fabry’s, Glycogen storage disease, hypothyroidism, Mucopolysaccharidoses
Amyloidosis, Sarcoidosis

HCM
Echocardiography:

Determining the pathophysiology of HCM.
Quantitating its morphology and hemodynamic severity.
Assessing the acute, chronic responses to various therapies.
Provide assistance during therapeutic procedures.
Insight into the epidemiology, inheritance and prognosis.

HCM
Diagnosis:

Asymmetric septal hypertrophy (ASH)
Septal to posterior wall thickness ratio > 1.3 (1.5), septum that is typically at least 15mm.
In children, LV wall measurements are more than 2SD above the mean (corrected for age and body surface area).
*30mm - sudden death risk.

HCM – LVH, Severity, Distribution and Patterns

PLX, serial PSX.
10 point system
Maron classification.
Pitfalls: Focal hypertrophy especially apical regions with sub-optimal windows and beware of oblique cuts.

HCM

Maron I : isolated anterior septum (10%).
Maron II : pan-septal without free wall involvement (20%).
Maron III : septum and antero-lateral free wall (52%).
Maron IV : all other types of hypertrophy (18%).

HCM - LVOTO
M-mode evaluation:

Narrowing of the LVOT
Mid-systolic notching of the aortic valve (no relationship with severity).
SAM of the mitral valve

HCM -LVOTO
Factors contributing to LVOTO:

(A) Narrowing of the LVOT by
(1)septal hypertrophy
(2)anterior displacement of the mitral apparatus
(3)anterior displacement of the papillary muscle

(B) HydroDynamic forces
(Venturi and drag forces) due to rapid early LV ejection with elongated mitral leaflets.

HCM – LVOTO - SAM

Occurs with the onset of the pressure gradient. (significant relationship with the obstructive gradient).

M-mode echocardiographic classification of SAM:

(1)Mild: SAM septal distance >10mm
(2)Moderate: SAM septal distance <10mm>HCM - LVOTO
(3)Severe: prolonged SAM septal contact, lasting more than 30% of systole.

HCM-LVOTO

Colour-flow mapping.
PW doppler – always start from the apex
CW doppler – spectral profile with a leftward concave shape (dagger shape).
Gradient (4V2), inducible by exercise techniques.
*LVOTO to MR doppler profile. MR doppler profile is earlier in onset, abrupt initial increase in velocity and a higher peak velocity (>5.5m/s).
Gradient: 30mmHg

HCM - MR

Evaluate valve morphology.
Mid to late systole.
Typical posterior-directed jet, presence of non-posterior jet suggest intrinsic mitral valve abnormality.
Related to the degree of anterior leaflet SAM, to the length of the posterior leaflet and the degree of mid systolic coaptation of the leaflets.

HCM – DIASTOLIC FUNCTION

Diastolic function is impaired.
Impaired LV relaxation pattern.
Filling pressures: Colour M-mode and tissue doppler techniques (TDI).
Asynchronous relaxation: base to apex (intracavitary IVRT flow), in ASH – base to apex flow and in apical HCM, apex to base flow.

HCM - TDI

Reduced Ea (detect genotype positive without LVH).
E/Ea with VO2 max, FC and serious events.
Ea to monitor response to invasive therapies.

HCM - TDI
Tissue doppler

Sa (lateral) < 13cm/s 100% Sensitivity 93% Specificity Sa (septal) < 12cm/s 100% Sensitivity 90% Specificity Ea (lateral) < 14cm/s 100% Sensitivity 90% Specificity Ea (medial) < 13cm/s 100% Sensitivity 90% Specificity

HCM – Strain Imaging

Myocardial strain allows the assessment of regional myocardial function.
Differentiate HCM from hypertensive heart disease.
Systolic strain of < -10.6% (85% sensitive, 100% specific, accuracy of 91%). All components of systolic strain is reduced in HCM.

Thank you and good luck

Checklist for 2D Echo/M-Mode/Doppler/TDI image acquisition in sequence

Image optimization – able to visualize endocardial border
Depth and focus
Framerate if 2D strain
Colour doppler scale/ aliasing velocity ≥ 60cm/s
Colour doppler gain (optimize by overgain then decrease untill no more background “speckling”)
Allow 3 – 5 beats for each looping


PLAX (1) with Desc Thoracic Ao
PLAX (2) without Thoracic Desc Ao
PSLAX(3) M-Mode Ao/LA
PSLAX (4) M-Mode Mitral Valve Tip (Colour M-Mode if SAM)
PSLAX (5) M-Mode LV at chordae level 

ASE guideline
Note: If heart orientation is distorted then direct 2D measurement to replace M-mode measurement
PSLAX (6) Zoom Aov and Mv
PSLAX (7) Colour Aov and Mv
Parasternal RV inflow (1)
Parasternal RVinflow (2) with colour
Parasternal RVinflow (3) CW for TR
Parasternal RVoutflow (1)
Parasternal RVoutflow (2) with colour
Parasternal RVoutflow (3) CW for PR (PW followed by CW if infundibular or valvular PS
Parasternal SAX (1) AO/MPA
Parasternal SAX (2) Colour PA
Parasternal SAX (3) PW RVOT
Parasternal SAX (4) CW PV
Parasternal SAX (5) Zoom Aov
Parasternal SAX (6) Colour Aov
Parasternal SAX (7) TV
Parasternal SAX (8) Colour TV for TR
Parasternal SAX (9) IAS with colour
Parasternal SAX (10) Basal LV (Zoom MV if MS )
Parasternal SAX (11) Colour MV if MR
Parasternal SAX (12) LV mid
Parasternal SAX (13) LV Apex
Parasternal SAX (13) LV Apex
Apical 4Ch (1) – All 4 Chambers in
Apical 4Ch (2) – LA and RA volume
Apical 4Ch (3) – Zoom LV
Apical 4Ch (4) – Zoom LV, measure EF (Single plane simpson’s)
Apical 4Ch (5) – Rotate to apical 2Ch
Apical 4Ch (5) –Measure EF (biplane simpson’s)
Apical 4Ch (6) – Assess RV
Apical 4Ch (7) – measure TAPSE and TDI s wave
Apical 4Ch (8) – Colour and CW MV - quantitate MR of MS if present
Apical 4Ch (9) – Colour and CW TV - quantitate TR of TS if present
LV diastolic function
Sample volume (1 – 2 mm) at tip of MV
(guide by colour to align the cursor parallel to flow – angle < 20°
E vel, A vel, Decel time

Sample Volume at MV annulus level
Mitral A duration

Source : Anderson, B., (2002), The Normal Examination and Echocardiographic Measurements.


LV Diastolic Function (1) Mitral Inflow
LV Diastolic Function (2)Mitral A duration
LV Diastolic FunctionIVRT and Pul Vein
3. Sample volume 2 – 3 mm in-between MV and AoV
IVRT

4. Sample volume 3 – 5 mm at pulmonary vein 1-2cm into pulm vein (preferably RUPV)
PVs vel, PVd vel, PVar peak vel, PVar duration

Source : Anderson, B., (2002), The Normal Examination and Echocardiographic Measurements.

LV Diastolic Function (3) IVRT
LV Diastolic Function (4)Pulmonary Vein
LV Diastolic FunctionPW TDI
5.Sample Volume 3 mm at MV septal annulus
TDI E’ Vel, A’ Vel, S’ Vel

6.Sample Volume 5 mm at MV lateral annulus
TDI E’ Vel, A’ Vel, S’ Vel

TDI sensitive to angle – align cursor parallel to annulus motion


Source :Hill, J.C, and Palma, R. A.“Doppler Tissue Imaging for the Assessment of Left Ventricular Diastolic Function: A Systematic Approach for the Sonographer”, JASE 2005, Vol 18, No 1, pp80 - 88

LV Diastolic Function (5)TDI Septal Annulus , Use PW TDI
LV Diastolic Function (6)TDI Lateral Annulus , Use PW TDI

Apical 4Ch
Assess MV and TV with colour doppler

Apical 5Ch
2D followed by colour

Apical 2Ch
2D followed by colour

Apical 3Ch
2D followed by colour

Apical 5 Chamber (1) – 2D loop
Apical 5 Chamber (2) – Colour AovZoom Aov if AS or AR and Quantitate severity
Apical 5 Chamber (3) – PW LVOT
Apical 5 Chamber (4) – CW AoV
Apical 2 Chamber (1) – 2D Loop
Apical 2 Chamber (2) – Colour MVQuantitate MR
Apical 3 Chamber (1) – 2D loop
Apical 3 Chamber (2) – Colour MVQuantitate MR, Zoom MV if necessary
Great Vessels
If aortic root dilated in PSLAX, then go one ICS up to visualize the entire aortic root and ascending aorta
Ao annulus, trans-sinus of valsalva, Sino- tubular junction and ascending aorta

Finally IVC dimension and collapsibility to estimate RAP.

Pulmonary Artery Systolic Pressure = TR peak PG + RA pressure
Pulmonary Artery Diastolic Pressure = PR end diastolic peak PG + RA pressure

Other additional views/measurements depend on pathology
Other additional views (1) High parasternal view to visualize entire Ao root
Subcostal View (1) – 2D IVC and M-Mode IVC
Other additional views
Depend on abnormalities detected eg. if Ao root dilated, high parasternal view to visualize the entire Ao root; Suprasternal view for significant AR, Modified 4Ch for ASD, Subcostal view for pericardial effusion ….. etc
Other additional views (2) Suprasternal View if significant AR
Other additional views (2) Modified 4Ch for ASD
Other additional views (3) Subcostal 4Ch for Pericardial eff
RV diastolic function
Sample volume 3-5 mm at tip of TV (RV inflow or apical 4C )
Guide by colour so that angle< 20°
E vel, A Vel, Decel time

Sample volume 2 mm in Hepatic vein(HV)
HV systolic forward flow vel, Diastolic forward flow vel, A reversal vel
TV inflow
PW hepatic vein
Summary
Do the same measurement at the same location as this will lead to consistency in measurement and able to detect any changes especially in serial echo.

Always remember that different category of people see things in different depth when interpreting echo, if you are not sure of what you are scanning do not panic, record (standard views) before you call the expert to review.

At the end of the study you should have an answer or at least an explanation for the doctor who requested that particular echo.