Advanced Echo by Dr. Elizabeth J. Yetter, MD MHPE

on

 

Left Heart Evaluation

Anatomy & Normal Values

  • LV diameter (diastole): < 5.2 cm

  • LV wall thickness (diastole): < 1.2 cm

  • Left atrial diameter: < 4.0 cm



Cardiac Output

  • CO = Stroke Volume × Heart Rate

  • Stroke Volume = LVOT Area × VTI

    • LVOT Area = π × (LVOT diameter/2)²

    • VTI measured via PW Doppler in Apical 5-Chamber or Long Axis view

Tips for VTI Measurement

  • Optimize gain, baseline, and sweep speed

  • Measure over several cardiac cycles (especially in atrial fibrillation)

  • Use passive leg raise (PLR) or fluid bolus to assess volume responsiveness

    • >10% increase in SV or >15% increase in VTI → fluid responsive

Ejection Fraction (EF) Assessment

  • Visual estimation: Normal 50–70%, Hyperdynamic >70%, Severe <30%

  • EPSS (E-point septal separation):

    • <7 mm = normal EF, >10 mm = low EF

    • EF ≈ 75.5 − (2.5 × EPSS)

  • Fractional Shortening (FS):

    • Normal: 25–45%

    • FS ≈ ½ of EF; less reliable with regional wall motion abnormalities

  • Simpson’s Method (Method of Discs):

    • Most accurate; requires A4C & A2C views + software

    • EF = (EDV – ESV) / EDV × 100


Cardiac Output (mL/min)= Heart Rate (beats/min) x Stroke Volume (mL/cycle)

Stroke Volume (cm3)= LVOT area (cm2) X VTI (cm)

Where LVOT is the Left Ventricular Outflow Tract area and VTI is the Velocity Time Interval


Measuring VTI

Obtain either Apical 5 Chamber or Apical Long Axis with clear outflow tract
At level where LVOT measured, place Pulsed Wave Doppler Gate
Must be in middle of blood flow
Select VTI and trace the negative wave form




Images Tips for Getting the Best VTI Tracing
Adjust your Gain
So you can see the whole waveform
Adjust your Baseline
So you capture the top of the wave form
Adjust your Sweep Speed
So you have enough cycles to choose the best one (or measure 5-10 waveforms for atrial fibrillation)

LVOT diameter, VTI, & Passive Leg Raise

Using the VTI method to obtain stroke volume, calculate while the patient’s head of bed is at 30 degrees
Provide 250mL fluid bolus
Raise legs to 45 degrees with head down and remeasure stroke volume after approximately 30 seconds
A change in stroke volume of >10% or change in VTI >15% indicates volume responsiveness



Ejection Fraction
EPSS
Fractional Shortening
Simpson’s Method (Method of Discs)

A note on Hyperdynamic EF 
Greater than 70% EF
It is NOT just tachycardia although often seen with tachycardia
Both walls of LV touch
Often due to hypovolemia





E-Point Septal Separation (EPSS)
<7 mm = Normal EF
>10mm = Low EF
LVEF=75.5-(2.5xEPSS)
Not valid if Mitral Stenosis, Mitral Regurgitation, Mitral Valve Calcification or Aortic Regurgitation, Mitral Annulus Dilation due to Cardiomyopathy or Extreme LV Hypertrophy


Fractional Shortening
If significant cardiovascular disease or regional wall motion abnormalities, it will be inaccurate
Does not account for the heart being a 3D object
Normal is 25-45%
FS is usually half the ejection fraction
FS=[(4.11-2.81)/4.11]*100= 31.6%


Simpson’s Method of Discs

Require special software
Need A4C and Apical 2 Chamber views
Trace the endocardial borders
Most accurate estimate of EF
LVEF= (EDV-ESV)/EDV*100



Right Heart Evaluation

Anatomy & Measurement

  • RV Free Wall Thickness: <5 mm (measured in diastole, subxiphoid view)

  • Measure RV:

    • Width above annulus and mid-ventricle

    • Apex to annulus length

Functional Measures

  • TAPSE (Tricuspid Annular Plane Systolic Excursion):

    • <17 mm = RV dysfunction

    • <14 mm = poor prognosis

  • S' (Systolic Excursion Velocity) via Tissue Doppler:


    • 10 cm/s = normal

       Right Heart

       

       

Anatomy
Right Free Wall <5mm
Thickened in Pulmonary Hypertension, Heart Failure, Cardiomyopathies
Measure from Subxiphoid view in Diastole
Anatomy
Measure just above the annulus on the screen

Anatomy
Measuring RV size
Width just above the annulus
Width Mid- ventricle
Length from apex to annulus

TAPSE
Tricuspid Annular Plane of Systolic Excursion
In A4C view, place M-Mode marker along the right free wall over the tricuspid annulus
Measure from the peak to trough of the annulus movement


Interpretation

*American Society of Echocardiography cutoffs
<17mm = RV dysfunction 
<14mm = poor prognosis, survival implications


S’ or Systolic Excursion Velocity

TAPSE measures how FAR the annulus moves, S’ measures how FAST the annulus moves
Select Pulse Wave Doppler and then set to Tissue Doppler instead of M-Mode just apically to the Tricuspid Annulus
>10cm/s is considered Normal
S’

Ventricular Overload

Pressure overload 🡪 Systolic Dysfunction
Pulmonary Embolism
Volume overload 🡪 Diastolic Dysfunction
Massive Fluid Bolus (MTP)



Chronic vs Acute Changes
RV Free Wall Thickness >5mm
In Diastole from the Subxiphoid View
Hypertrophied trabeculae, moderator band, papillary muscles
Acute on Chronic- Need to compare echos

🫁 Pulmonary Circulation & Volume Status

Eccentricity Index (EI)

  • Differentiates pressure overload (PE, pHTN) from volume overload (MTP, CHF)

  • EI seen in parasternal short axis view: flattened septum suggests pressure overload

Pulmonary Artery Systolic Pressure (PASP)

  • PASP = RVSP + RAP

    • RVSP = 4v² (where v = peak TR velocity)

    • RAP estimated by IVC size/collapsibility

      • IVC >2.1 cm & <50% collapse → RAP ~15 mmHg

  • PASP >36 mmHg = abnormal


Eccentricity index


⏱️ 60/60 Sign (Suggestive of Pulmonary Embolism)

  • PASP <60 mmHg

  • Pulmonary Acceleration Time (PAT) <60 ms

    • Measure via PW Doppler in RVOT

    • 94% specificity for PE when both <60

🩸 Pathology Recognition

Pulmonary Embolism

  • TAPSE ↓, 60/60 sign, Eccentricity Index

  • McConnell’s sign not specific (also seen in pHTN, ARDS, RV MI)

Cardiac Tamponade

  • RV diastolic collapse (specific, 60% sensitive)

  • RA systolic collapse (94% sensitive)

  • Plethoric IVC, low cardiac output

  • Use M-mode for pulsus paradoxus detection

📸 Extra Views

  • Suprasternal notch: Aortic arch and dissection evaluation

  • Apical 2- & 3-Chamber: Required for Simpson’s method

Comments

Post a Comment