AE 1.5 - Measurements, CAD, Stress Echo, & Wall Segments

Accurate / proper measurements

1. On-axis image

2. Timing of cycle

- (ie: end-diastole, end-systole, mid-systole)

3. Location

- use landmarks per ASE guidelines

4. Plane

- perpendicular to the structure of interest

Differences between M-mode & 2D measurements

M-mode

- best temporal resolution (best timing)

- 1D information regarding a particular cardiac structure as it relates to time & distance

- the strength of the reflected echo is represented as the brightness of structures appearing on the image display

2D

- main tool for a comprehensive echo study

- 2D image

- the strength of the reflected echo is represented as the brightness of structures appearing on the image display

Simpson's Biplane Method

- take LV & LA dimensions from both 2C & 4C

- use this method to get EF of LV

LV = should be less than 10% difference in lengths between 4C & 2C

LA = should be less than 5mm difference in lengths between 4C & 2C

Why Simpson's Biplane Method is preferred for LV volume calculations

- uses 2D info

- uses info from 2 different views

- allows for more unique volumes/areas along LV length via disks

A4C RV focused view (m-mode)

TAPSE

> 1.7cm

- align m-mode cursor along RV free wall as perpendicular to the lateral tricuspid valve annulus as possible

- distance measured leading edge of annulus to from end-diastole to end-systole

PLAX measurements (diastole)

IVSd

LVIDd

LVPWd

timing

- end-diastole: onset of the QRS, first frame after MV closure or frame in which the cardiac chamber is largest

- taken at MV leaflet tips

PLAX measurements (systole)

LVIDs

timing

- end-systole: frame after AV closure or the time in when cardiac chamber is smallest

- taken at the MV leaflet tips

Zoomed AV measurements

*LVOT

*Aortic annulus

timing

- mid-systole: AV open

- LVOT: should be taken 5-10mm proximal to annulus (before av)

Zoomed aortic root measurements

*Aortic sinuses

*STJ

Ascending aorta

timing

- end-diastole: onset of the QRS or frame before AV opens

High PLAX Asc Aorta measurements

Ascending Aorta

timing

- end-diastole: onset of the QRS or frame before AV opens

PSAX @ AV RVOT measurements

*RVOT

timing

- mid-systole: PV open

- RVOT: should be taken 5-10mm proximal to annulus

A4C Zoomed LV measurements

LVEDV (4C)

LVESV (4C)

LVEF

- should be less than 10% difference in lengths between 4C & 2C

- trace the LV cavity along the interface of the compacted and noncompacted myocardium of the chamber wall excluding papillary muscles

-- make sure LV length is centered

timing

- ventricular end-diastole: one frame after MV closure or when LV is at its largest

- ventricular end-systole: one frame immediately preceding MV opening or when LV is at its smallest

A4C Zoomed LA measurements

LAVI (4C)

- should be less than 5mm difference in lengths between 4C & 2C

- trace the LA cavity from medial to posterior annulus excluding LAA and pulm veins

-- make sure LA length is centered

timing

- ventricular end-systole: one frame immediately preceding MV opening or when LA is at its largest

RA focused A4C measurements

RA area/volume

- trace the RA cavity from medial to posterior annulus excluding RAA

- make sure RA length is centered

timing

- ventricular end-systole: one frame immediately preceding TV opening or when RA is at its largest

RV focused A4C measurements

RV dimensions

Basal: basal 1/3rd of RV

Mid: Middle 1/3rd of the RV at the level of LV pap muscles

Longitudinal: mid-plane of tricuspid annulus to the RV apex

timing

- ventricular end-diastole: one frame after TV closure or when RV is at its largest

**Do not measure TV annulus at the base

RV focused A4C (FAC) measurements

*RV Fractional Area Change (FAC)

- trace along RV endocardium, including RV trabeculations, papillary muscles & mod band in RV area

timing

- ventricular end-diastole: one frame after TV closure or when RA is at its largest

- ventricular end-systole: one frame immediately preceding MV opening or when LV is at its smallest

A2C Zoomed LV measurements

LVEDV (2C)- Biplane

LVESV (2C)- Biplane

LVEF- Biplane

- trace the LV cavity along the interface of the compacted and noncompacted myocardium of the chamber wall excluding papillary muscles. Make sure LV length is centered

timing

- ventricular end-diastole: one frame after MV closure or when LV is at its largest

- ventricular end-systole: one frame immediately preceding MV opening or when LV is at its smallest

A2C Zoomed LA measurements

LAVI (2C) - Biplane

- trace the LA cavity from medial to posterior annulus excluding LAA and pulm veins

-- make sure LA length is centered

timing

- ventricular end-systole: one frame immediately preceding MV opening or when LA is at its largest

Subcostal IVC measurements

IVC

measurements must be perpendicular to IVC walls taken inner edge to inner edge

make measurement 1-2 cm from the junction of the IVC into the RA

Subcostal Ao measurements

*Descending Aorta

measurements must be perpendicular to aorta walls taken inner edge to inner edge

SSN measurements

*Aortic Arch

measurements must be perpendicular to aorta walls taken inner edge to inner edge

between Innominate artery and LCCA

make sure not to include any of the branching arteries

Proper imaging views for right -sided measurements

PSAX @ AV level

- RVOT

A4C

- RA focus & area/volume

- RV focus & dimensions & fractional area change

Subcostal

- IVC

- RAP

Proper imaging views for left -sided measurements

PLAX

- IVSd

- LVIDd

- LVPWd

- LVIDs

Zoomed AV

- LVOT

- Aortic Annulus

Zoomed aortic root

- Aortic Sinuses

- STJ

- Ascending Aorta

High PLAX

- Ascending Aorta

A4C Zoomed LV

- LVEDV (4C)

- LVESV (4C)

- LVEF

A4C Zoomed LA

- LAVI (4C)

A2C Zoomed LV

- LVEDV (2C) - Biplane

- LVESV (2C) - Biplane

- LVEF- Biplane

A2C Zoomed LA

- LAVI (2C) - Biplane

Subcostal

- Descending Aorta

SSN

- Aortic Arch

Common measurement errors

1) foreshortening

-- apicals = go low & lateral

-- plax = go high & medial

2) incorrect alignment

-- always stay perpendicular to walls 丄

-- inner vs leading edge

3) poorly defined borders

-- must see walls of structure

Circulation

Pulmonary

RA → TV → RV → PV → Main PA → RPA & LPA → Capillaries

O2 = 75%

Systemic

LA → MV → LV → AV → Aorta → Peripheral arteries → Arterioles

O2 = 95%

Coronary

arteries = to myocardium from Aorta base

veins = away from myocardium & back to RA

Coronary Circulation

fill primarily during ventricular diastole

Major branches of the Left Main Coronary Artery

- left anterior descending coronary artery

- left circumflex coronary artery

LAD

left anterior descending coronary artery

- travels down towards the anterior aspect of the heart

- feeds the anterior, septal, & apical walls

- small branches called perforators supply the IVS

- may supply a portion of the RV apex, moderator band, and the SA node 50% of the time

LCx

- left circumflex coronary artery

- gives rise to obtuse marginal branches

RCA

right main coronary artery

- primary coronary supply to the RV

- also supplies the SA node, AV node, RA, parts of the IVS, IAS, & Inferior LV wall

Posterior descending artery (PDA)

- RCA gives rise to PDA in 85% of patients, this is called “right dominance”

- originates from either the right coronary artery (right dominant), left circumflex artery (left dominant), or both (codominant)

Myocardial regions supplied by each coronary artery

LAD

Anterior wall

Anteroseptal wall

LV apex

LCx

Anterolateral (Lateral) wall

Inferolateral (posterior) wall

RCA

Inferior wall

Inferoseptal wall

RV apex

RV free wall

Coronary sinus & venous drainage of the myocardium

Coronary Sinus

- 3 veins drain into coronary sinus: small, middle, & great cardiac vein

- located in the posterior part of the coronary sulcus

- predominantly collects blood from the myocardium & drains into the inferoposterior aspect of the RA

- guarded by a small crescent shaped Thebesian valve

- Anterior Right Ventricular Veins

- Thespian Veins

Basic development of coronary artery disease

-

Angina

Unstable

- characterized by chest pain that occurs suddenly and unexpectedly at rest and/or pain that is more severe or prolonged than prior

Stable

- generally occurs with exercise and is relieved by rest or nitrate medications

Ischemia

decreased blood flow to the heart myocardium

Infarction

blood flow completely cut off resulting in tissue death

Myocardial remodeling

- stunning

- myocardial function is still depressed for a variable period of time even when blood flow is restored to area

- induced by acute ischemia

- is temporary

- the changes in the size, shape, structure, and electrical properties of the heart in response to injury, disease, or chronic stress

Ischemic cascade

-

The sequence of events following reduced coronary blood flow

ischemia --> diastolic dysfunction --> systolic dysfunction --> EKG changes --> chest pain

perfusion abnormalities --> wall motion abnormalities --> EKG changes --> angina, MI, death

Echocardiographic appearance of infarcted myocardium

1. Myocardium becomes akinetic

- happens within hours, surrounding tissues may be “stunned”

2. Myocardium thins after infarction

3. Acoustic impedance of myocardium changes as scarring and healing occurs

- becomes more echogenic (very bright)

Common location of left ventricular thrombus after MI

apex

True aneurysm

- thin, dyskinetic

- wider neck than pseudoaneurysm

- bulge distorts the normal contour of the LV cavity

- contains all layers of myocardium (NOT a rupture)

- apical, inferior, & posterior areas are most common

- low risk of rupture

Pseudoaneurysm

- narrow neck

- free wall of LV ruptures and a hemopericardium is contained

- walls = thrombus & pericardium

- higher risk of free rupture of myocardium – survival is rare

- most common location is basal inferior segment – NOT APICAL

Post-MI Pericarditis

- Dressler's syndrome

- occurs 1-8 weeks after MI

- inflammation of pericardium

- will hear friction rub murmur

Common indications for stress echocardiography

- Evaluation of Symptoms

-- chest pain/angina

-- SOB

-- fatigue

- baseline EKG symptoms

- known CAD

- risk stratify before non-cardiac surgery, post-MI, after intervention (PTCA, CABG)

- evaluation Valve disease

- HCM gradients (hocm)

Contraindications (should not do) for Stress Echo

MI in last 48 hours

Unstable Angina

Uncontrolled HTN

Uncontrolled arrhythmias

Severe AS

Decompensated CHF

Mobile LV thrombus

Acute aortic dissection

Basic exercise stress echo protocol

baseline

- resting images of LV (6)

4C, 2C, 3C, PLAX, Pap muscles, Apex

post-exercise

- continuous capture

- has 60sec to get the 6 images again

Importance of obtaining post-exercise images quickly

- sonographer has 60 seconds from the time the treadmill stops to obtain peak/post exercise images AND with the HR be above target HR

- false negative test from a delay in obtaining images

17-segment model (bullseye)

pay attention to septal insertion landmark

outer --> inner:

- basal --> mid --> apical --> apex

anterior v inferior

septal v lateral

17-segment model

pay attention to septal insertion landmark

Wall segments (chamber views)

4C -- 2C -- 3C

IS AL -- I A -- IL AS

"i saw a lion -- in africa -- it loved angry sheep"

Basal segments

basal anterior

basal anteroseptal

basal inferoseptal

basal inferior

basal inferolateral

basal anterolateral

Mid segments

- has papillary muscles

mid anterior

mid anteroseptal

mid inferoseptal

mid inferior

mid inferolateral

mid anterolateral

Apical segments

apical anterior

apical septal

apical inferior

apical lateral

LISA

Apex segments

apical cap/apex

Relationship between coronary artery territories & wall motion abnormalities

-

Wall motion

hyperkinetic = -1 = more vigorous than normal

normokinetic = 1 = normal wall motion

hypokinetic = 2 = reduced wall motion

severely hypokinetic = 2.5 = severely reduced wall motion

akinetic = 3 = no/little wall motion

dyskinetic = 4 = abnormal motion

aneurysmal = 5 = aneurysmal motion/bulging