Basic LV and RV assessment

Justin Bowra

Critical Care Ultrasound Course

Summary

Keep it simple2D imaging only

The Goldilocks method

A simple rule

Assess LV/RV size in diastole (tells you about preload)

Find where the LV/RV looks LARGEST

Assess LV/RV function in systole

Find where the LV/RV looks SMALLEST

DIASTOLE SYSTOLE

Qualitative or quantitative?

The Goldilocks Approach

How cardiologists assess LV size & function

a. Sonographer guesstimate: bizarrely, the most accurate!

b. LV fractional shortening (PLAX) c. End-diastolic area method (PSAX) d. Simpson’s method (A4C and A2C)

PLAX: LV size & fractional shortening

• B mode or M mode• Freeze image & measure LVIDd & LVIDs- ‘simple!’• Normal LVIDd = 3.9–5.3cm (F) / 4.2-5.9 (M)• Normal LVFS = [(LVIDd – LVIDs)/LVIDd] = 25-45%

Pitfalls:• Need to get PLAX just right• Need to measure at just the right spot• 1D measurement of a 2D image of 3D structure! (i.e.

assumes symmetry)

RV

LVLA

RV

LVLA

A B

Pitfall

PSAX: End-diastolic area method

IHYPOVQLAEMlA ORMA!L DILATED

End-diastolic area method

Parasternal SAX (B mode) Mid-way down the papillary musclesn Trace endocardial border at end diastole The machine does the rest! Normal LV in diastole: 8-14cm2 (70kg male) Normal LVEF = 55-70%

Pitfalls

Needs to be at the right level (mid papillary muscle) Needs to be perpendicular to heart's long axis Needs to be a good view! Need the right software Need time!

A4C, A2C: Simpson’s method

Simpson’s method

A4C and A2C views Trace endocardial border at end diastole ‘The machine does the rest!’ Divides 2D image of LV into segments Normal LV end diastolic volume: men 67-155 mL, women

56-104 mL

Pitfalls

Can only be done from apical window Bloody difficult!

– Finding the right window– Finding the endocardium

Notoriously easy to under- / overestimate

‘Echocardiography is a science’

‘Echocardiography is a science’

At best it’s semiquantitative… i.e. subjective.

Even the best echocardiographer has bad days.

And this tells you nothing about diastolic failure. (Need other tricks eg tissue Doppler)

How we do it in BELS:A rough 'eyeball' approach

The rough guess

Too big? Too small? Grossly normal? (NOT ‘Just right’) Experienced full-time cardiac sonographers are very

accurate at this But for us, only useful at extremes

The trick is to recognise what’s normal.

(And that it’s just grossly normal)

What’s normal?

LV internal diameter in diastole (LVIDd): ROUGHLY 4– 6cm (PLAX)

LV free walls and IV septum: 0.6 – 1.0 cm

RV internal diameter in diastole: up to 2/3 of LV diameter

RV free wall < 0.6 cm

LA up to 4cm diameter, RA up to 4.5

Aortic root: up to about 4cm (PLAX)

What’s normal?

LV internal diameter in diastole (LVIDd): ROUGHLY 4– 6cm (PLAX)

RV internal diameter in diastole: up to 2/3 of LV diameter

Normal function

Normal LV: moves substantially, but doesn’t ‘kiss’

Normal RV: moves substantially, but doesn’t squash the LV

How’s this LV?

How’s this LV?

Caveat

All these numbers are averages.

They change with age and sex (M>F)

They change with BSA (e.g. small people have small hearts)

LV

The ‘grossly normal’ LV

SIZE: LVIDd = 4–6cm (PLAX)

FUNCTION: moves substantially, but doesn’t ‘kiss’

TEST

Window?LV size?

LV contraction?

Top tip

If in doubt, look from different windows.

Top tip

Remember the ‘mimics’(eg LVH mimicking hypovolaemia)

Top tip

Try different windows(eg subcostal SAX)

RV

The ‘grossly normal’ RV

SIZE:

Internal diameter in diastole = up to 2/3 of LV diameter

FUNCTION: Moves substantially, but doesn’t squash LV

Top tip

RV contracts more in the long axis (watch the tricuspid valve)

TEST

Window?RV contracting?

RV big?RV squashing LV?

Top tip

Make sure probe is round the right way!

Look for aortic rootTV is closer to apex than MV

LV

RV

Top tip

Thick RV free wall =chronic cor pulmonale

Putting it together

What the ventricles can tell you in basic echo

Is this hypovolaemic shock?

Is this hypovolaemic shock?

Small, collapsing IVC

Small LV

LV systolic kissing

NB beware LVH, HOCM, & cylinder artifact

Is this cardiogenic shock?

Is this cardiogenic shock?

Large IVC

Large LV (only if chronic)

LV may be contracting ‘normally’ (NB diastolic failure)

NB beware the chronically crappy heart with acute septic shock

Is this septic shock?

Is this septic shock?

This can be tricky!

IVCSmall (systemic vasodilation) …

Or large (because of hypocontractile heart)…Or ‘normal’

LV‘Kissing’ (systemic vasodilation)… Or hypokinetic (septic ‘stunning’)…

Or ‘normal’

Is this obstructive shock?

Is this obstructive shock?

Add lung, IVC

Tension PTX: check lungs, IVC

Tamponade: check IVC, RV

Massive PE:Occasionally RV/ pulm a thrombus

RV bigRV squashes LV

False positive = chronic cor pulmonaleFalse negative = lower grade cor pumonale

You’re not in Kansas now

Cardiac US is harder than you think

And this is just 2D

Summary

Chamber size in diastole, function in systole

Know normal dimensions

Practice +++ on normal patients & those with known pathology

Stick to Goldilocks

Avoid overcalling things (the big trap)… try different windows if in doubt

Know the limitations of BELS (eg ‘minor’ cor pulmonale)

Thanks to

Sharon KayConn Russell