Chamber Quantification

What views visualize the left atrium?

PLAX

PSAX

Apical 4, 5, 2, 3

SC 4C, SAX

TEE: transgastric long axis, 2Ch, lower/middle esophageal, upper esophageal

Why are TEE views not optimal for accurate dimension measurements of LA?

Because the entire LA frequency cannot be fit in the image sector

What phase are LA measurements taken?

End-systole = atria at biggest size, just before MV opens

How is LA diameter measured in M-mode?

in PLAX, perpendicular to Ao root and measured at level of the Ao sinuses from LE to LE

How is LA diameter measured in 2D?

in PLAX with perpendicular orientation to LA posterior wall

How is LA area measured?

Measured in AP4 at end-systole by tracing the LA inner border

^{excludes area under MV annulus and inlet of Pv}

How is LA volume measured using the Biplane area-length technique?

1. tracing the LA area of blood-tissue interface on AP4 and AP2

2. Measure the LA length in AP4 and AP2

3. Calculate volume using formula

What is the volume formula for Biplane area-length technique?

LA_vol = (0.85 x A₁ x A₂) ÷ L

How is the LA volume measured using the Simpson's biplane method of disks?

disk summation technique: adding the volume of a stack of cylinders of height and area calculated by orthogonal minor and major transverse axes, D1 and D2

What is the volume formula for Simpson's biplane method?

LAvol = (D1 x D2 x D3) x 0.523

What is the LA volume index (LAVI)?

LA volume ÷ BSA measured _(ml/m²)

BSA

body surface area

What major physiologic roles does the LA fulfill?

1. Contractile pump that delivers 20-30% of LV filling (atrial kick)

2. Reservoir that collects Pv return during systole

3. Conduit for the passage of stored blood from LA to LV during early diastole

What is the purpose of M-mode and 2D echo in LA function assessment?

Assessing LA dimension and motion of anterior LA wall (posterior Ao wall)

What is the purpose of Doppler in LA assessment?

A-wave of MV inflow representing atrial systole

A max velocity (VTI)

LA contractility

A-time/duration

Length of atria systole

What structures are relevant to the LA function?

1. LA appendage

2. Interatrial septum

3. Pulmonary veins (Pv)

What is the purpose of measuring max velocity at the mouth of LAA in TEE?

correlates with force of LA contraction/emptying

What views can visualize integrity abnormalities of the interatrial septum?

PSAX @Ao , AP4, SC 4Ch, LA TEE

What can help visualize shunts and pressure gradient calculations when such shunts exist?

Color doppler interrogation

What views are the pulmonary veins visualized?

AP4, SSN SAX and TEE

What is the purpose of doppler for Pv?

Assesses LA pressure, important evaluation of LV diastolic function

What would a higher AR wave of Pv doppler indicate?

High LA pressures, which suggests abnormal diastolic function

What is LAE a marker for?

Severity of diastolic dysfunction + magnitude of LA pressure elevation

What patients typically show LAE?

• Patients with significant MV disease

• atrial arrhythmias

• LV systolic and diastolic dysfunction

• LV pressure overload

• congenital heart disease

• cardiac transplantation

What is LAE associated with, and what is the consequence?

Thrombus formation in LA, can cause embolization in cerebral arteries → stroke

What does the bowing of the IAS towards the RA suggest?

LA dilation or increased LA pressure

What is the LA/Ao ratio?

LA can be compared to Ao with a 1:1 ratio

What can a dilated Pv and LAA suggest?

LA dilation + Increased LA pressure

What are common interatrial septal abnormalities?

ASD, aneurysm, PFO, lipomatous hypertrophy

What is an IAS aneurysm?

midportion of atrial septum billows

What is lipomatous hypertrophy?

Fatty infiltration of superior and inferior portions of IAS can create dumbbell-shaped LA

What is PFO?

Patent foramen ovale, allowing intermittent blood flow in bidirectional fashion between two atria

How can the PFO shunt be identified?

• Color doppler in PSAX@Ao, AP4, SC4, TEE

• Contrast echo with saline bubbles - enhanced with Valsalva maneuver

• Quantification of shunting - accurate with TCD

What can dilation of the Pv suggest?

Increased LA pressure

What does abnormal Pv flow patterns suggest?

LA pressure changes associated with diastolic dysfunction, severe MV disease, constrictive pericarditis, restrictive cardiomyopathy

What are the views visualizing the RA?

AP4

SC 4ch

PSAX@Ao

TEE:

- ^{Mid-esophageal basal 4-Chamber view}

^{- Mid-esophageal turned 60-90 degree to patients' right to view RVOT+RVI}

^{- Mid-esophageal Bicaval view at 80-110 degree}

^{- Transgastric long axis of right ventricle 0 degree}

Where are RA dimensions primarily taken?

2D at Apical 4Ch at end systole

Where is major dimension of RA measured?

Longitudinal measurement from TV annulus parallel to the IVS to superior right atrial wall

Where is minor dimension of RA measured?

Go perpendicular to long-axis, mid-level of right atria free wall to IAS

Where is the RA area measured?

Trace around RA across the TV annulus and exclude SVC and IVC and RAA

When should RA area be obtained ?

• routinely in patients with known RV/LV dysfunction

• when RA is visually larger than LA

How do you obtain RA volume in 2D?

Simpson biplane method by tracing RA wall at end-systole → RAv= (D1 xD2 xD3) x 0.523

What is RAVI?

RA volume index = RA_vol ÷ BSA

How is RA pressure measured?

It is estimated by evaluating the IVC via sniff test.

• Dilated IVC that does not collapse = 15-20 mmHg

• Dilated IVC that collapses = 10-15 mmHg

Where can color doppler for RA be seen?

In AP4, PSAX, RVIT but are only used for qualitative data

What is a good indication of RAE?

If RA is larger than LA

What are right atrial functions?

• Contractile pump that delivers blood to RV

• Receives and stores deoxygenated blood from SVC, IVC, and coronary veins during ventricular systole

What is the purpose of 2D in RA function assessment?

Assess the RA dimensions, atrial septum motion and collapsibility of IVC

What is the purpose of Doppler in RA function assessment?

Assessment of RA filling done by viewing flow patterns of IVC or hepatic veins in SC 4Ch

What are the parts of the spectral wave form of IVC and Central Hepatic Vein?

Systolic = S

Diastolic = D

Atrial kick = a

When is there increased filling in the RA?

During inspiration (expansion of thoracic cavity= sucks in venous return)

What is the eustachian valve?

The fetal remnant of the valve of the IVC

What is the Chiari network?

Fetal remnant of the valve to the coronary sinus

What is the crista terminalis?

C-shaped ridge of tissue in the RA, ranging from SVC to IVC

What is a marker for RV systolic and diastolic function?

RAE

A deviated IAS toward the LA throughout the cardiac cycle may be a sign of...

Increased RA volume/pressure

RAE or dilation can be present in patients with the following:

• Tricuspid valvular disease (TR, TS)

• RV pressure overload (PHTN)

• Atrial fibrillation

• Congenital Heart Disease

• Cardiac transplantation

• Sleep Apnea

What does the bowing of the IAS toward the LA + distortion of the right heart with no movement suggest ?

compression by extracardiac structures within the liver or mediastinum.

What can the bowing of the IAS toward the LA with a mass in RA is suggestive of?

A cyst or tumor

When is a thrombus in the RA appendage commonly found?

In consequence of low flow, atrial arrhythmia, or Prescence of catheters and pacemakers

A multilobed, freely mobile, and wormlike thrombi is more likely formed in?

Lower extremities

What 10 views visualize the RV?

1. PLAX

2. RVIT

3. RVOT

4. PSAX @Ao

5. PSAX @MV

6. PSAX @PM

7. AP4

8. AP5

9. AP3

10. SC 4Ch

Structures of RV

• TV

• PV

• RV free wall

• IVS

• Moderator band

Where is the RV free wall thickness measured?

at end-diastole using Subcostal 4Ch or PLAX

_{^{Using 2D or M-mode - measure at the tip of the anterior TV leaflet, assessing the RV dimensions and wall motions}}

What is the normal free wall thickness?

≤ 0.5 cm

Where is 2D RV linear dimension measured?

In 2D at AP4 at end diastole

Where is d1 measured?

Basal diameter → base of chamber from corner to corner behind TV leaflets

What is a normal d1?

≤ 4.2 cm

Where is d2 measured?

Mid-cavity dimension → measure at the middle third of RV at level of papillary muscles, stay under MB

What is a normal d2?

≤ 3.5 cm

Where is d3 measured?

Longitudinal dimension → measure at mid plane of the TV annulus to RV apex

What is a normal d3?

≤ 8.6 cm

How is RVOT dimension measured?

In 2D at PSAX or subcostal at end-diastole

Where is RVOT proximal (RVOT₂) measured?

Using PLAX or PSAX AO measure RVOT

What is a normal RVOT proximal?

≤ 3.3 cm

Where is RVOT distal (RVOT₃) measured?

Using PSAX Ao measure RVOT near the PV annulus

What is a normal RVOT distal?

≤ 2.7 cm

What is the function of the RV?

Contractile pump that delivers unoxygenated blood into pulmonary circulation

How do you measure RV area and Fractional Area Shortening?

Using 2D at AP4, trace at the TV annulus, along the wall to the apex, down the IVS, and back to the annulus

• Perform this in end-diastole AND end-systole

What is an abnormal FAC?

Less than 35%

What is TAPSE?

Tricuspid annular plane systolic excursion → Amplitude of the free wall up and down during peak systole

how do you measure TAPSE?

Using M-Mode at AP4, Place cursor through TV annulus and measure the longitudinal motion of TV anulus at peak systole

What is a normal TAPSE?

1.7 - 3.1 cm

Why do we use tissue doppler imaging at RV and how do you measure it?

• Measuring the speed of the tissue moving up and down

• In AP4, place gate at the TV annulus or in the middle of basal segment to measure peak systolic velocity

What is a normal S' ?

10-14 cm/s

How do you assess RV diastolic function?

RV diastolic function follows the pattern of the LV, so it is discussed with LV diastolic function

What is RV dysplasia?

The replacement of RV myocardium with adipose or collagen

What are common signs of RV dysplasia?

• RV enlargement

• focal RV wall motion abnormalities

• localized aneurysms of free wall

How does RV dysplasia appear in ultrasound?

echogenic

What is ARVD and what does it cause?

Arrhythmogenic Right Ventricular Dysplasia is a rare form of familial RV cardiomyopathy, may cause Vtach and sudden cardiac death

What happens in a hypercontractile RV?

Pulmonary hypertension, pulmonary embolism, long term sleep apnea

What causes RV volume or pressure overload?

Constrictive pericarditis and cardiac tamponade

What is a result of RV volume or pressure overload?

Ventricular interdependence: Septal shift and D shaped LV