Amaali vids: [Dilated RV on ECHO](https://www.melbourneus.com/rv-matters-on-echo/), [RV thrombus](https://www.melbourneus.com/r-heart-thrombus-podcast/) see also: [[Right Ventricle POCUS]], [[FELS]] [Oh’s valve lesions table](x-devonthink-item://49C9C33E-BFC4-4CAE-99BB-110FA7246880?page=379) #incomplete # Doppler concepts | mode | explanation | use | | --------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------- | | Continuous wave | - all velocities along the scan line are analysed and displayed, but the specific velocity at a given depth cannot be determined ("range ambuguity")<br>- used to measure higher velocities | - tricuspid regurg<br>- aortic regurg<br>- aortic stenosis | | pulsed wave | - gives a velocity at a specific point (range specificity)<br>- "duplex doppler"<br>- useful for localised measurement in areas of turbulent flow<br>- limited by *aliasing* | - mitral inflow for MR<br>- LVOT VTI<br>- RVOT VTI | | colour flow | - special form of pulsed wave doppler<br>- real-time two-dimensional doppler with colour-coding of the doppler signal <br>- non-quantitative; measures only *direction* and *variance* | | # overview table | valve lesion | key ECHO findings | key management | | ---------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------- | | Aortic regurg | - jet width < 25% (0.3cm) mild, 25-64% (0.3-0.6 cm) mod, ≥ 65% (0.6 cm) severe<br>- best on PLAx<br>- pressure half-time of >500ms mild, <200ms is severe | | | Aortic stenosis | - AV area (*AVA*) < 1 cm2. < 0.76 severe<br>- *peak velocity* (continuous wave) <3m/s mild, >4m/s severe<br>- *mean gradient* >25 mmHg significant ; > 50 critical (calculated with tracing doppler cardiac output with VTI; if poor LV function, degree of stenosis will be underestimated)<br>- best on PLAx<br><br>∴ if the valve leaflets are thin, mobile, and separate widely in systole, then severe stenosis can be excluded <br>- A5C can be used for quantitative assessessment of AS by continuous wave doppler | | | mitral regurg | | | | mitral stenosis | | | | tricuspid regurg | - continuous wave 4m/s severe TR | | # Regurgitant lesions see: [[Valvular disorders]], [EMCrit - Critical Aortic & Mitral Regurgitation](cubox://card?id=6948681985581646272) any valvular regurgitation can be described on POCUS in terms of three components: 1. the flow convergence zone 2. vena contracta 3. the regurgitant jet # Cardiac output and VTI ![[Pasted image 20241127175005.png]] # ECHO technique table | technique | description | values | | -------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------- | | [[#LVEDD]] | M-mode one dimensional estimate of *pre-load* (eg if small may infer hypovolaemia)<br><br>big isn't necessarily good; may be dilated (see fractional shortening) | 4.2 - 5.8 cm in males<br>3.8 - 5.2 cm females<br>indexed 2.2-3 cm/m2 males | | [[#Fractional shortening]] | approximation of ejection fraction | normal 28 - 44% | | [[#LVOT VTI]] | - use pulse wave in A4C<br>- measure 0.5 cm proximal to aortic valuve | 15-25 cm - normal<br>10 cm - poor | | Stroke volume | = CSA x LVOT VTI<br><br>CSA = 0.785 x D^2 (LVOT) | normal ~ 90 mL | | Cardiac output | = SV x HR | normal ~ 5L/min | | Ejection fraction | | normal 52-72 (male) ; slightly higher female | ## LVEDD ![[Pasted image 20241127184823.png| normal sized LV with LVEDD of 4.6 cm]] ![[Pasted image 20241127184917.png|dilated LVEDD of 6.6 cm]] ## Fractional shortening > $\text{FS (\%)} = \frac{\text{LVEDD} - \text{LVESD}}{\text{LVEDD}} * 100$ - ↓ FS value is <28% - ↑ FS value is >44% - Normal FS value is 28-44% ![[Pasted image 20241127185239.png| dilated, poorly contracting LV. LVEDD = 6.6 cm; FS 15%]] ## LVOT VTI ![[Pasted image 20241216170718.png]] ![[Pasted image 20241216170817.png]]