echocardiography

Equipment required in echocardiography

US machine, table, restraint, ECG pads, sector transducers (to get between ribs)

Types of views - a

Long axis view

Types of views - B

Short axis view

Types of views - Which is best to see most cardiac issues

R para sternal long axis 4 chamber view

Types of views - RPS view which chamber is clostest to probe

RV

Timings- end diastole

Start of QRS complex

Timings- End systole

Smallest LV dimension/ end of T wave

Views - which structures on R of screen (except L apical 4 chamber view)

Basilar structures/ R sided

Which chamber is A

LV

Which chamber is B

LA

LV wall thickness

¼ - 1/3 chamber diameter

Levels of short axis views - a

Papillary

Levels of short axis views - B

Mitral

Levels of short axis views - C

Aortic

Levels of short axis views - D

LV

What level is at widest part of heart

Chordae tendinae

What does M-mode echocardiography show

Wall thickness/position over time/ ECG

Fractional shortening shows what

Contractility, systolic function

Fractional shortening normal value

>25%

Fractional shortening not reliable when

Significant mitral regurgitation

Wall motion abnormalities

R heart disease with pressure overload

How many times does M valve open in systole

2

What to assess in initial home view

Chamber size

Wall thickness

Systolic function

Abnormality seen

Arrhythmia

LV dilated + hypokinetic

Inc EPSS

→ dilated CMP

What is EPSS

E point to septal separation

Ejection fraction (%) equation

((EDV-ESV) / EDV) x 100

Normal ejection fraction

>50%

Index of sphericity for LV equation

LV length in diastole / LV width

Index of sphericity for LV normal value

>1.7

Abnormalities seen + potential causes

Concentric hypertrophy of LV

→ sub aortic stenosis, systemic hypertension, hypertrophic CMP

Abnormalities seen +CS/ what happens

Pericardial effusion (attached to heart base, collapsed RA in diastole)

→ collapse, R heart failure

Cardiac tamponade

Collapsed RA due to pericardial effusion

How does a Doppler work

Blood towards transducer → high frequency reflection → positive frequency shift

Why is it important for Doppler to be parallel to blood flow

Cos = 1 so accurate reading of blood velocity

What does the blue line show

RBC velocity (acceleration + deceleration)

Pulsed wave Doppler

Focuses on 1 area (box) so more accurate than continuous

Continuous wave Doppler

Shows velocity at multiple depths

Pulsed vs continuous wave spectral Doppler

P- spatially specific

C- depth recording, high velocity

Which shows laminar flow

A

When is turbulent flow seen

Valve regurgiation

Colour flow Doppler - red colour meaning

Towards probe

Colour flow Doppler - Blue colour meaning

Away from probe

Colour flow Doppler - Best range for accurate colours

1- 80cm/s

E peak meaning

Early filling - mitral valve opening

A peak meaning

A contraction

Why is the blood blue when moving LV → aorta

Away from probe

Green colour meaning + common cause

Turbulent flow (M regurgitation)

When is continuous wave used (view)

Parallel to flow

Abnormalities seen

M valve nodular thickening, prolapse + sev M regurgitation

LA dilation

Nodules moving with valve so not endocarditis

Myxomatous mitral valve disease

What is IVS (hyperkinetic in mitral valve disease)

Inter V septum

Flail chorda def

Ruptured chordae tendinae in mitral valve disease

Endocarditis appearance

Nodules move independently of valve (thromboemboli)

Inf CS

What is most central structure in short axis view at base

Aorta

Normal LA: Ao diameter

<1.5:1

Causes of LA enlramgent

Mitral regurgitation

HCM

Swirling appearance in LA cause / def

Saddle thrombi → LA thrombus (smoke)

Structures in 5 chamber view

RV, LV, LA, RA, aorta

Sub aortic stenosis appearance

LV concentric hypertrophy

Turbulence at narrowing

Aortic regurgiation

Sub costal view features

Probe parallel with aorta flow (press hard into chest)

How does pressure gradient vary with velocity (equation)

PG = 4 x velocity²

Severity of stenosis with pressure - a

<50

Severity of stenosis with pressure - B

50-80

Severity of stenosis with pressure - C

>80

Normal cardiac pressures - RA

4

Normal cardiac pressures - RV

25/0

Normal cardiac pressures - pul a

25/10

Normal cardiac pressures - LA

6

Normal cardiac pressures - LV

120/0

Normal cardiac pressures - aorta

120/80

Abnormality seen + causes

RV concentric hypertrophy (squashed LV)

Pul stenosis, pul hypertension

Super thick wall meaning

Myocyte hyperplasia so congenital

How to calculate RV pressure in pul stenosis

PG of RV-PA + normal PA pressure

When are the walls moving together (parallel movment(

Systole

Abnormality seen (R long axis view)

RV pressure overload from pul hypertension → LV underfilled

Pericardial effusion

Abnormal structures in RA (dirofilaria)

R pul a thrombus

Dirofilariasis (caval syndrome) normally found

Pul a, RA, RV

How to extract dirofilaria worms

Jug vein

Worm species found in heart from lungs

Dirofilaria

POCUS stands for

Emergency point of care US

Purpose of POCUS in dyspnoeic animal

Identify pleural effusion + drain

Identify hyperechoic lines (B lines)