Valves

Valves

Valvular assessment

FUSIC HD similar to BSE level 1 aims to assess the aortic, mitral and tricuspid valves for any significant problems that could be causing haemodynamic instability. 

The main basic ways to do this are with visual assessment and colour flow doppler assessment. 

Within the FUSIC HD curriculum spectral doppler is used for assessment of the aortic valve and this is also covered below. 

Values will be given to help grade severity below but this is not part of the FUSIC HD scan, but hopefully will be useful to help distinguish normal and significantly abnormal valves. 

General approach to valvular assessment

The key components to the assessment of valves are:

  • Visual assessment
  • Colour flow doppler
  • Spectral doppler across aortic valve

Visual

Perform 2D visual assessment of aortic, mitral and tricuspid valves from all available views, assessing for:

  • Thickness, calcification, mobility
  • Forward/backward flow through the valve – looking at valve opening/restriction during systole and valve closure during end-systole/diastole.
  • Any flail or prolapse?
  • Any masses adherent to the valve?
  • Any destruction of the valve?

Colour doppler

Assess valves with colour flow doppler, looking for regurgitation. 

Ensure that the echo beam plane is fanned through the whole of the valve in each view. This will help determine where the regurgitation is maximal. 

Considerations:

  • Box size – should cover the whole of the valve and the chamber which the regurgitant jet flows into 
  • Nyquist limit – assessing regurgitation should be set to 50-70cm/s
  • Vena contracta – size is proportional to size of regurgitant orifice
  • Flow convergence and jet area – both represent regurgitant volume

Cautions

  • Eccentric regurgitant jets into chamber walls will have reduced velocity and look less severe.
  • Haemodynamic instability will affect the pressure gradient across valves – e.g. low systolic BP will lead to reduced velocity of mitral regurgitation (if present) leading to underestimation.  

A3Ch view assessing mitral valve regurgitation
Note the nyquist limit in the top right of the image set at 54.2 cm/s.

Images:

Nyquist limit example

Vena contracta 

Flow convergence and jet area

Normal valves visual and colour 

Fanning through valves

How different views may look more or less severe because of the angle of blood flow against the probe. 

Spectral doppler

Only used on the aortic valve in FUSIC HD.

  • Peak velocity is measured using continuous wave (CW) doppler through the aortic valve – this can be used to grade severity 
  • Dimensionless index can also be calculated 

Cautions

  • Can underestimate peak velocity if incorrectly aligned (note cannot overestimate)
  • Large angle between US beam and the direction of blood flow will also underestimate velocity (particularly >20 degrees)

Valvular assessment

  • FUSIC heart clinical questions:
  • FUSIC heart clinical questions:
  • FUSIC heart clinical questions:

Aortic valve assessment

Views

Aortic valve assessment should take place in all views in which the aortic valve is seen. The best views are:

  • PLAX
  • PSAX – aortic valve level
  • A5Ch
  • A3Ch
 

Anatomy of aortic valve

The aortic valve is tricuspid with the three leaflets named after the coronary artery which arises from the associated sinus. 
 
These are called the right, left and non-coronary cusps. 
 
INSERT IMAGE LABELLED PLAX AND PSAX AV LEAFLETS
 

INSERT VIEWS OF normal AV in all views

PLAX, PSAX AV, A5Ch A3Ch

Aortic Stenosis

Abnormalities of aortic valve

The commonest causes of aortic valve degeneration leading to stenosis are:
  • Calcific
  • Bicuspid aortic valve
  • Rheumatic 

Visualisation of the valves thickness, mobility and calcification is important. 

Clinical features of severe aortic stenosis

  • Syncope
  • Angina
  • Dyspnoea

Echo assessment aortic stenosis

  • Visual
    • Thickened/calcified aortic valve leaflets
    • Reduced mobility of valve
    • Reduced leaflet opening
  • Colour flow doppler
    • Increased flow velocity/turbulent flow
    • At the valve level and downstream 
  • CW doppler of AV 

Other echo features in severe AS

  • Look for aortic regurgitation and other valvular abnormalities
  • Look for evidence of left ventricular hypertrophy
  • Look for aortic root dilatation 

PLAX view - Aortic valve thickened, calcified with restricted opening. Visually severe aortic stenosis.

PSAX AV level - zoomed in on aortic valve - showing severely calcified trileaflet aortic valve

Spectral doppler assessment of aortic valve

CW doppler across aortic valve

The best alignment of the CW doppler is in the A5Ch and A3Ch views. The doppler is placed through the line of the LVOT and AV and a sample is taken. 

The baseline needs to be moved up on the screen so that the doppler trace below the line can be seen and the scale may need to be adjusted.

Care needs to be taken when aligning the CW doppler sample line as if it is slightly off it will underestimate the actual velocities across the AV. 

Peak velocity (Vmax)

Look at the shape of the doppler and measure on the ultrasound machine the peak of the doppler trace. This will give you the Vmax value in m/s.

>4m/s is indicative of severe aortic stenosis. 

This is a flow dependent parameter so can be underestimated in low flow states. 

Dimensionless index (DI) 

On the doppler trace from the CW through the AV it is sometimes possible to see two traces. The large one from the aortic valve and a smaller on inside the doppler trace which is from the LVOT. 

Trace around both the AV and the LVOT doppler signals to obtain the velocity time integral (VTI). 

The continuity equation is one way to work our aortic valve cross sectional area (CSA). 

LVOT VTI x LVOT CSA = AV VTI x AV CSA

Rearranged to:

AV CSA = (LVOT VTI x LVOT CSA)/AV LVOT

This gives a value in cm², however, inaccuracies in measuring the LVOT diameter can lead to significantly inaccurate results. This is because the diameter needs to be converted to the cross sectional area using πr². So any inaccurate measurements are squared. 

The continuity equation shows us how the LVOT VTI and AV VTI are related to the AV and can be used to give a ratio if the LVOT CSA is removed from the equation. This ratio is known as the dimensionless index and the equation is:

AV dimensionless index = LVOT VTI/AV VTI ratio

<0.25 indicates severe aortic stenosis

Clinically, instead of using VTI ratio (LVOT VTI/AV VTI), the velocities can be used instead as their ratios are nearly identical. Therefore:

AV dimensionless index = LVOT Vmax / AV Vmax

The dimensionless index has it’s advantages because it is less flow dependent than AV Vmax and it is less affected by the angle of the spectral doppler to flow across the aortic valve. 

CW doppler through the aortic valve - Vmax is about 4m/s indicating severe aortic stenosis. It is possible to visualise the smaller LVOT VTI trace within the AV VTI trace. The LVOT Vmax is visually about 1m/s. This would give a DI = 1/4 = 0.25

References for severe aortic stenosis

Severe

Visual

Heavily thickened & calcified
Severely restricted opening

Colour

Turbulent flow
At the valve level and downstream

CW Vmax

>4m/s

Dimensionless index

<0.25

Aortic Regurgitation

Echo assessment aortic regurgitation

  • Visual
    • Valve prolapse?
    • Vegetations consistent with infective endocarditis?
    • Aortic root dilatation or dissection flap?
  • Colour flow doppler
    • Jet extension back into LV – not a reliable marker of severity
    • Width of Jet in LVOT (within 1cm of AV)
    • Vena contracta width (narrowest region of colour flow at AV level) 
 

Other echo features in aortic regurgitation

  • Look for aortic stenosis and other valvular abnormalities
  • Look for evidence of left ventricular dilatation
  • Look for aortic root dilatation 
 
Severity of aortic regurgitation
  • VC width >0.6cm is severe
    • This cannot be measured if more than one regurgitant jet
  • Jet width ratio with LVOT >65% is severe
    • This is misleading in eccentric jets

For the FUSIC HD curriculum measurements of the vena contracta or jet width ratio with the LVOT are not expected, but these values help to give an idea of what severe aortic regurgitation may look like visually. 

 

Aortic Root

Aortic root can be measured in the PLAX view . This is covered in the aorta section of FUSIC HD. 

Measurement of proximal ascending aorta:

  • Inner edge to inner edge
  • End diastole 
  • 1cm above the sino-tubular junction 

A value >40mm indicates dilated proximal ascending aorta

 

Mitral valve assessment

Views

Mitral valve assessment should take place in all views in which the mitral valve is seen. The best views are:

  • PLAX
  • PSAX – mitral valve level
  • A4Ch
  • A3Ch
  • A2Ch
 

Anatomy of mitral valve

The mitral valve is made up from the mitral valve annulus, two mitral valve leaflets (anterior and posterior) and the subvalvular apparatus (the papillary muscles and chordae tendineae).

There are two papillary muscles:
  • Posteromedial papillary muscle – attached to mid-inferior LV wall
  • Anterolateral papillary muscle – attached to mid-anterolateral LV wall

The papillary muscles attach to the mitral valve via the chordae tendinae, and each papillary muscle supplies chordae that attach to both mitral valve leaflets.   

Mitral Stenosis

Abnormalities of mitral valve

The commonest causes of mitral valve degeneration are:
  • Mitral annular calcification 
  • Rheumatic 

Visualisation of the valves thickness, mobility and calcification is important. 

Echo assessment mitral stenosis

  • Visual
    • Thickened/calcified aortic valve leaflets
    • Reduced mobility of valve
    • Reduced leaflet opening
  • Colour flow doppler
    • Increased flow velocity/turbulent flow
    • At the valve level and downstream 

Other echo features in severe mitral stenosis

  • Dilated LA +/- spontaneous echo contrast
  • AF
  • Pulmonary hypertension
  • RV dilatation or dysfunction 
  • Tricuspid regurgitation

Mitral Regurgitation

Echo assessment mitral regurgitation

  • Visual
    • Valve prolapse or flail?
    • Vegetations consistent with infective endocarditis?
    • Calcification/thickening?
    • Annular dilatation?
  • Colour flow doppler
    • Jet extension back into LA 
    • Vena contracta width (narrowest region of colour flow at MV level) 
    • Size of PISA

References for severe mitral regurgitation

Severe

Visual

Flail or prolapse

Colour

Jet area >10cm²
Ratio of jet area to LA area >40%
VC width >/=0.7cm
PISA radius >1cm

Causes of mitral regurgitation

Primary
(leaflet abnormality)

Secondary
(ventricule remodelling)

Prolapse, flail, rupture

Ischaemic

Degeneration, calcification

Non-ischaemic cardiomyopathy

Infective endocarditis, vegetations

Annular dilatation

Inflammatory - rheumatic

Congenital

Causes of mitral regurgitation

Acute mitral regurgitation
Echo features

  • LV & LA are normal size
  • LV appears hyperdynamic

Clinical features

  • Sudden onset
  • Severe breathlessness
  • Hypotension and cardiogenic shock
  • Acute coronary syndrome
  • Acute pulmonary oedema
Chronic mitral regurgitation
Echo features
  • Enlarged LA, LV and RV
  • Normal/reduced LV contractility

Clinical features

  • Gradual onset 
  • Slowly progressive breathlessness on exertion
  • Atrial fibrillation
 Indirect indicators of severity of MR
  • LA dilatation
  • LV dilatation
  • LV dysfunction
  • Pulmonary hypertension

Tricuspid valve assessment

Views

The best views for tricuspid valve assessment are:

  • RV inflow view (RVI)
  • PSAX – aortic valve level
  • A4Ch
 

Anatomy of tricuspid valve

The tricuspid valve as the name suggests is made up from 3 leaflets. The septal, anterior and posterior leaflets. 

Causes of tricuspid valve disease
 
Tricuspid valve regurgitation is commonly caused by:
  • Rheumatic disease
  • Infective endocarditis
  • Carcinoid
  • Valve prolapse
  • Annular dilatation – secondary to RV dilatation (functional TR) 
  • Pacing wire passing into RV
Tricuspid stenosis is commonly caused by rheumatic fever and will have accompanying mitral stenosis. Rarer causes of tricuspid stenosis is carcinoid which commonly also affects the pulmonary valve (right heart valves). 
 

Tricuspid Regurgitation

A small amount of tricuspid regurgitation is present in about 70% of individuals with a structurally normal heart. 

Echo features of tricuspid regurgitation

  • Visual inspection
    • Look at annulus, leaflets, papillary muscles and chordae
    • Look at thickness, mobility, calcification and for signs of prolapse
  • Colour
    • Jet area >10cm²
    • VC width >/=0.7cm
  • CW doppler – jet density/contour
    • Density – dense = moderate to severe
    • Contour – triangular early peaking = severe
  • PW doppler in hepatic vein (VEXUS) – normally directed towards RA throughout cardiac cycle, predominant systolic component
    • S wave blunted in moderate TR
    • Reversed in severe TR
  • RA/RV/IVC size – dilated in severe

    The severity of TR does not correlate with the PA pressure

Although the CW doppler and PW doppler are not used to assess severity of TR in FUSIC HD, the CW doppler is used to work out TR Vmax when measuring pulmonary artery pressures and the PW doppler of the hepatic vein is used in the VEXUS assessment. So it may be useful to know about grading severity of TR using these different methods as they may be measured for other reasons. 

Severe TR

MAPSE

This is taken in the A4Ch view. As the LV contracts in systole in shortens longitudinally, radially and circumferentially. The distance that the MV lateral annulus travels in systole towards the LV apex is measured and this is known as the MAPSE.

To get the MAPSE value the A4Ch view is obtained and the M-mode line is placed over the lateral annulus of the MV. When in the correct position record M-mode by pressing the button again and freeze the screen once a few cardiac cycles have been recorded by M-mode. Place the calipers on the M-mode image and measure the lowest and highest points of the line of the MV.

MAPSE >12mm predicts normal LV function

MAPSE < 6mm predicts severe LV systolic dysfunction

MAPSE is good for distinguishing between normal and significant impairment of the LV, but is harder to interpret when the value lies between 6-12mm. 

MAPSE measurement taken in M-mode with the cursor over the lateral mitral valve annulus.

Measurements taken from lowest to highest point of the line on M-mode representing the mitral annulus.

Fractional shortening

Fractional shortening can be useful because it is not too dissimilar to measuring the LVIDd. Again it is taken in the PLAX and LVIDd is measured, but at the same time LV internal diameter in systole is measured along the same plane as the LVIDd.

Systole can be determined by a few different ways:

  • The frame where the LV is at its smallest
  • The frame after AV closure
  • The end of the T wave

This is a PLAX view of the LVIDs (measuring at 2.60cm)

Fractional shortening is then calculated using these 2 values:
FS = [(LVIDd – LVIDs)/LVIDd] x 100

This is a normal value for fractional shortening

BSE reference for fractional shortening

LV function

Fractional shortening

Normal

25-43%

Mildly impaired

20-24%

Moderately impaired

15-19%

Severely impaired

<15%

Fractional shortening can be prone to inaccuracies in RWMAs and if any foreshortening of the LV has taken place when obtaining the image. It does not take the whole of the LV into account and so can be prone to error.

RWMAs

In health the LV contracts and the walls thicken and they move equally towards the centre of the LV cavity. Whilst looking at the LV from the PLAX, PSAX and A4Ch it is important to assess how the LV is contracting in all the different areas of its walls.

RWMAs can be due to ischaemia such as in an acute coronary syndrome and in this case the RWMA will be in the area supplied by the affected blood vessel. The RWMA will look like reduced excursion and thickening in this case. For FUSIC heart one of the ways to assess for RWMAs is to look in the PSAX at the papillary muscle level. The LV should be circular and all areas of the LV should be contracting and thickening equally towards the centre.

The main blood supply from the heart is from the left and right coronary arteries. The left coronary artery divides from the left main stem (LMS) into the left anterior descending artery and the left circumflex artery (LCx). The LAD provides blood supply to the left anterior side of the heart and the LCx provides blood to the left lateral and posterior area of the heart. The right coronary artery (RCA) supplies blood to the right side of the heart – including the right atrium, ventricle, the sino-atrial (SA) node and atrioventricular (AV) node.

PSAX view showing antero-septal RWMA - note the reduced contractility in the upper left corner of the LV on this clip

Blood supply to the heart ↔︎

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PLAX view showing the areas of coronary blood supply to the LV

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PSAX view showing the areas of coronary blood supply to the LV

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A4Ch view showing the areas of coronary blood supply to the LV - the lateral free wall of the LV can sometimes be supplied by the LCx.

Summary

Using the knowledge of the assessments above and gaining experience in scanning the LV, over time, you will get better at using an ‘eyeball’ assessment of the LV and answer the questions:

  1. Is the LV dilated?
  2. Is the LV significantly impaired?

Right ventricular assessment

The RV can be assessed from the:

  • PLAX – RVOT
  • PSAX – RV size and septal shape
  • A4Ch – RV size & function (TAPSE)
  • Subcostal – global impression

If the patient has a dilated LV then this rule can lead to underestimating RV size, and if the image is foreshortened then this can lead to overestimating the RV size.

The main view for assessing the RV size and function is the A4Ch view but the other views can be helpful as well.

3. Is the RV dilated?

The main way to assess for RV dilatation is in the A4Ch view. This is done using an ‘eyeball’ assessment where the LV and RV are seen next to each other. The RV is determined to be normal size when the RV basal width is no more than 2/3 that of the LV.

RV is mildly dilated when it is >2/3 the basal width of the LV
RV is moderately dilated when it is equal to the size of the LV
RV is severely dilated when it is larger than the LV

 

The PSAX is not usually used to assess RV size but can give an indication of whether RV dilatation is present – see images below. 

No RV dilatation - A4Ch view showing the RV roughly 2/3 the size of the LV and the LV is the apex forming ventricle

RV severely dilatation - A4Ch view showing RV basal diameter > LV basal diameter

PSAX view of a normal RV

PSAX view of dilated RV

If the patient has a dilated LV then this rule can lead to underestimating RV size, and if the image is foreshortened then this can lead to overestimating the RV size.

4. Is the RV severely impaired?

RV systole is predominantly in the longitudinal plane with some inward motion of the RV free wall. This makes the tricuspid annular plane systolic excursion (TAPSE) reflects longitudinal function and equates well with RV ejection fraction – making it ideal for measuring systolic function of the RV. The technique is similar to the MAPSE but performed on the lateral annulus of the tricuspid valve.

To measure the TAPSE get an optimal view in the A4Ch and place the M-mode line through the lateral annulus of the tricuspid valve. Press M-mode again and freeze the image after a few cardiac cycles. Measure using callipers the distance from the highest to the lowest point of lateral annulus of the tricuspid valve.

BSE reference values for TAPSE:

  • TAPSE ≥17 is normal
  • TAPSE <10mm is severely impaired.

TAPSE assessment using M-mode with a measurement of 2.05cm from the lowest to the highest point of the lateral annulus of the tricuspid valve. This is a normal TAPSE.

TAPSE assessment using M-mode with a measurement of 0.95cm from the lowest to the highest point of the lateral annulus of the tricuspid valve. This indicates the RV is severely impaired.

5. Is there evidence of low preload? (vasodilation/hypovolaemia)

The methods used to assess for low preload within FUSIC heart are inferior vena cava (IVC) assessment, combined with LV/RV assessment.

In a low preload state, which can be either due to vasodilation (for example in sepsis), or hypovolaemia (for example in dehydration/blood loss), the LV and RV will appear on echo to be hyperdynamic to try and increase the cardiac output through increasing the heart rate or contractility. This can be assessed in all views but may be well visualized in the A4Ch view.

In severe hypovolaemia there may be evidence of papillary muscle apposition in systole in the PSAX view. This gives the impression that most of the LV is emptying during systole and is evidence that there is low preload and the LV is underfilled.

The IVC assessment is also used to assess preload, however, it will differ depending on whether the patient is spontaneously breathing or is mechanically ventilated – which is not ideal for the ITU population for which FUSIC heart is used.

IVC

The IVC is assessed using the subcostal view with the probe rotate through 90 degrees anticlockwise from the original view of the heart. This brings into view the IVC in its long axis passing through the diaphragm and draining into the right atrium. Using M-mode place the line through the IVC perpendicular to its walls 1-2cm before its junction with the RA. Measuring on the M-mode image the maximum and minimum distance using calipers, as the IVC diameter changes with respiration.

The IVC diameter changes with respiration due to a negative intrathoracic pressure during inspiration and a positive intrathoracic pressure during expiration. During inspiration the negative intrathoracic pressure draws blood from the IVC into RA and the diameter reduces. During expiration the opposite occurs. This is during spontaneous respiration.

Normal IVC diameter is 1.5-2.1cm – outside of these limits suggest hypovolaemia or well-filled fluid status.

Limitations of IVC measurement

The IVC size and reactivity can be affected by multiple factors, including:

  • Raised intra-abdominal pressure
  • Tricuspid regurgitation
  • RV failure

Spontaneous breathing and IVC assessment

An IVC diameter <2.1cm with collapsibility >50% with a sniff suggests right atrial pressure (RAP) 0-5mmHg

An IVC diameter ≥ 2.1cm with collapsibility <50% with a sniff suggests RAP of 15mmHg

Assume a RAP of 8mmHg for any other value that dies not meet the criteria above

SC IVC view in a spontaneously breathing patient with a sniff

SC IVC M-mode assessment of collapsibility with a sniff. Callipers can be used to measure between the largest and smallest diameter of the IVC.

Mechanically ventilated and IVC assessment

During mechanical ventilation there is positive intrathoracic pressure during inspiration and reduced intrathoracic pressure relatively in expiration. So the phasic collapse of the IVC is reversed.

The assumption is made that a dilated IVC with low respiratory variability reflects a high RAP (high preload).

A small IVC with high respiratory variability reflects a low RAP (reduced preload).

IVC measurement in M-mode showing a dilated IVC (2.57cm) with very little respiratory variation indicating a raised RAP - this could be due to RV failure or fluid overload

Putting LV and RV assessment together

So far we have seen how we can assess LV and RV size and function. It is important to be aware of the differences between the LV and RV and why they behave in the way they do with either pressure or volume overload.

Difference between LV and RV

The RV walls are thinner and the RV walls more compliant. This means the RV dilates acutely when exposed to pressure and volume overload. When dilatation is seen in the LV this is almost always due to chronic disease. The LV perfusion is only in diastole due to the higher pressures in the myocardium during systole and compression of intramuscular vessels. The RV is perfused in systole and diastole and predominantly supplied via the right coronary artery (RCA).

Difference between pressure and volume overload of the RV

In both severe pressure and volume overload RV dilatation is seen with a D-shaped septum on the PSAX view. In normal circumstances the LV is circular with the inter-ventricular septum bowed towards the RV. In conditions of pressure or volume overload the IVS can start to flatten and become D-shaped.

Depending on which phase of the cardiac cycle the IVS appears D-shaped will determine whether it is pressure or volume overload or a combination of the both.

Pressure overload – the IVS is D-shaped in systole

Volume overload – IVS is D-shaped in diastole, paradoxical septal motion may be present where hyperdynamic ventricles appear to move the septum anteriorly during systole.

Combination of both pressure and volume overload – IVS appears D-shaped throughout both systole and diastole.

In both pressure and volume overload the IVC will start to dilate >2cm and there will be minimal respiratory variability.

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PSAX view with a normal circular LV ↔︎

PSAX view of a D-shaped septum in both systole and diastole - indicating both pressure and volume overload

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PSAX view with a flattened inter-ventricular septum making the LV appear D-shaped ↔︎

6. Is there pericardial or pleural fluid?

Assessment for pericardial fluid should be made in all views of the heart. Fluid on echo appears anechoic (black) and for it to be pericardial fluid needs to be between the myocardium and the pericardium. It is normal to see very small amounts of pericardial fluid in some patients. In patients with high body fat content the epicardial fat pad can appear similar to pericardial fluid, however this has a much more granular appearance which can help distinguish it and it is usually small. The pericardial collection can either be concentric or localized and it is best seen in the PLAX and SC views.  

To distinguish between pericardial and pleural fluid this is best done in the PLAX view. Pericardial fluid appears anterior to the descending thoracic aorta whereas pleural effusions are posterior to the descending thoracic aorta.

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PLAX view showing a small amount of pericardial fluid below the infero-lateral wall of the LV. ↔︎

Note: The fluid is anterior to the descending thoracic aorta meaning it is pericardial and not pleural fluid
This is best distinguished in the deep PLAX view.

PLAX view showing a small amount of pericardial fluid below the infero-lateral wall of the LV.

The pericardial effusion size can be measured at end diastole perpendicular to the pericardium and myocardium.

Pericardial effusion size
Small < 0.5cm Moderate 0.5-2cm Large >2cm

Maximal measurements around each regional wall should be made.

The appearance of the effusion can help distinguish its cause:
Simple effusion – uniform, anechoic
Exudative/fibrinous – stranding/loculation
Old blood – echogenic & grainy
Acute blood – similar to simple serous effusion
Purulent effusion – echogenic

Deep PLAX view demonstrating fluid posterior to the descending thoracic aorta meaning that it is pleural fluid.

Are there any signs of tamponade?

Early signs of pericardial tamponade are:

  • IVC dilated, not collapsing
  • RA collapse in systole

Late sign:

  • RV early diastolic collapse → significant haemodynamic compromise

Very late sign:

  • LV/LA collapse

SC view with evidence of pericardial fluid

Peri-arrest echo – where it fits in

Focused echo can be used during cardiac arrest and fits into the ALS algorithm at the pulse check. Usually the only place to assess the patient is via the subcostal view and limited to only 10 seconds.

Echo during cardiac arrest can help distinguish between true PEA (where coordinated electrical activity is seen on the monitor but there is no cardiac movement on echo and no palpable pulse) and pseudo PEA (where there is coordinated electrical activity on the monitor but there is cardiac activity on echo but with no palpable pulse).

Resus council recommendations for USS imaging during ALS:
  • Only skilled operators should use intra-arrest point-of-care ultrasound (POCUS).
  • POCUS must not cause additional or prolonged interruptions in chest compressions.
  • POCUS may be useful to diagnose treatable causes of cardiac arrest such as cardiac tamponade and pneumothorax.
  • Right ventricular dilation in isolation during cardiac arrest should not be used to diagnose massive pulmonary embolism.
  • Do not use POCUS for assessing contractility of the myocardium as a sole indicator for terminating CPR.

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Content created by Ben Stoney
Design by Max Broadbent

The ultrasound images and clips used on this website have be reproduced following the local clinical governance guidance.