Basic Echocardiography

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Basic Echocardiography

• Wendy Blount, DVM
• Nacogdoches TX

2
Echo Technique - Anatomy

• Tricuspid valve
• Septal leaflet
• Parietal leaflet
• Pulmonic Valve
• Right cusp
• Left cusp
• Intermediate cusp

• Mitral valve
• Leaflets are less distinct
• Aortic Valve
• Right cusp
• Left cusp
• Septal cusp

3
Echo Technique - Anatomy

• RV
• Conus arteriosus
• 3 papillary muscles
• LV
• 2 papillary muscles

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Echocardiography

• Equipment
• Transducer small footprint
• Fan-shaped beam or sector
• High frequency for small animals
• Low frequency for large animals
• Machines range from 2.5-10 Mhz
• 5-7 MHz will work fine for most dogs and cats for
  echo

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Echocardiography

• Equipment
• Double window with simultaneous B and M modes
  (video)
• Can do measurements on B-mode or M-mode
• Need a cursor which can measure mm, or cm marks
  on the images
• Ability to capture images is important

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Echocardiography

• Preparation
• Thin coated animals alcohol, part the hairs,
  gel
• Thick coated animals shave the window at the
  sternum, just behind the elbow
• Sedation only if needed
• Acepromazine 0.025 mg/lb (max 1 mg)
• Buprenex 0.01-0.02 mg/kg
• Mix together and give IV (handout)

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Echocardiography

• Positioning for 8 standard views
• Right lateral recumbency
• Cardiac table is nice but not necessary
• Sonographer needs a stool or chair
• Placement of probe
• Feel the apical beat, and put your probe there
  (probe marker cranial)
• Imagine the longitudinal axis of the heart, probe
  at 90o (short axis views)
• Adjust 1 intercostal space Cr or Cd PRN
• Rarely move the probe head just fan and
  twist (video)

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1. Short Axis Left Ventricle

• Fan from base to apex, until you have just passed
  the mitral valve, and the LV papillary muscles
  appear (mushroom view)
• Rotate until PM are the same size
• If you are getting a rib shadow, try one
  intercostal space cranial or caudal
• Fan cranial and caudal to center the heart on the
  screen

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1. Short Axis Left Ventricle

• Abbreviations - Structures
• P pericardium
• RV right ventricle
• IVS intraventricular septum
• LV left ventricle
• PPM posterior papillary muscle
• APM anterior papillary muscle

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1. Short Axis Left Ventricle

• Measurements
• IVSTd - IntraVentricular Septum Diastole
• LVIDd - LV Inner Diameter Diastole
• LVPWd LV Posterior Wall Diastole
• IVSTs - IntraVentricular Septum Systole
• LVIDs - LV Inner Diameter Systole
• LVPWs LV Posterior Wall Systole

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1. Short Axis Left Ventricle

• Measurements
• IVSTd IVSd VSd
• LVIDd LVd LVLd
• LVPWd LVFWd LVWd
• IVSTs IVSs VSs
• LVIDs LVs LVLs
• LVPWs LVFWs LVWs

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1. Short Axis Left Ventricle

• Measurements - Calculated
• FS fractional shortening
• (LVIDd LVIDs)
• LVIDd
• Assumes perpendicular to myocardium
• Assumes contractility is uniform in the LV
• Extremes in preload and afterload can affect FS,
  as well as myocardial function

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1. Short Axis Left Ventricle

• Measurements - Calculated
• FS fractional shortening
• AKA shortening fraction (SF)
• gt30 in the dog
• gt40 in the cat
• gt45 if MR is compensated

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1. Short Axis Left Ventricle

• Measurements - Tips
• Make sure you dont include PM in the LVPW
  measurement
• If you do, your LVPW will be artifactually
  thicker
• Clue check for this if LVPW is much thicker
  than IVS
• Make sure you are not too far apical
• If you are, your LVID will be artifactually small
• And LVPW will be artifactually thick

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1. Short Axis Left Ventricle

• Measurements - Tips
• Measure three times
• Take the average
• Throw out any outliers
• Several sets of normals published
• 1-2mm outside normal may not always be significant

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2. Short Axis Apex

• Structures
• Pericardium
• May or may not see RV
• LV apical lumen
• No measurements here

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3. Short Axis Chordae Tendinae

• Structures
• Pericardium
• RV
• LV
• CH - Chordae Tendinae (posterior anterior)
• No measurements here

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4. Short Axis Mitral Valve

• Structures
• Pericardium
• RV
• RV Papillary Muscles
• LV
• MV - Mitral Valve (Posterior Anterior)

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4. Short Axis Mitral Valve

• Measurement
• EPSS E-Point to Septal Separation
• Can denote decreased LV systolic function
• Less than 6 mm in large dogs
• Less than 3-5 mm in small dogs and cats

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5. Short Axis Aortic Valve

• Structures
• RVOT Right Ventricular Outflow Tract
• TV Tricuspid Valve
• PV Pulmonic Valve
• Ao Aortic Valve
• LA Left Atrium

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5. Short Axis Aortic Valve

• Measurements
• Ao at largest dimension (systole)
• LA at largest dimension (diastole)
• LAAo
• 0.8 to 1.3 in dogs
• 0.8 to 1.4 in cats

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6. Short Axis Pulmonary Artery

• Structures
• RA Right Atrium
• Ao Aorta (ascending)
• PA Pulmonary Artery
• LPA left pulmonary artery
• RPA right pulmonary artery
• CaVC Caudal Vena Cava

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7. Long Axis 4 Chamber

• Technique
• Get short axis mushroom view
• Rotate 90 degrees counterclockwise

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7. Long Axis 4 Chamber

• Structures
• RV Right Ventricle
• RA Right Atrium difficult to view completely
• TV Tricuspid Valve
• LV Left Ventricle
• LA Left Atrium
• MV Mitral Valve, PM papillary muscle

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7. Long Axis 4 Chamber

• Video

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8. Long Axis LVOT

• Technique
• Find 4 Chamber view
• Angle the dot toward the shoulders
• Elevate the cord end of the probe

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8. Long Axis LVOT

• Structures
• RV, TV, RA
• LV, PM, MV
• Very edge of the LA
• LVOT AV (LC, SC), ascending Ao
• RPA Right Pulmonary Artery

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8. Long Axis LVOT

• Video
• Normal Dog Video

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Dog RV Measurement Values

• RVWd less than LVWd
• RVIDd 1/3 or less of LVIDd
• (handout)

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Cat Echo Normal Values

• IVSTd 3-6 mm
• LVIDd 10-21 mm
• LVPWd 3-6 mm
• IVSTs - 4-9
• LVIDs 4-11 mm
• LVPWs 4-10 mm
• Aos 6-12 mm
• LAd 7-15 mm

• FS - gt40
• EPSS - 0-3 mm
• EF - gt70
• LAAo 0.8-1.4
• RVIDd - 3-7 mm
• RVWd - lt3 mm
• (form)

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Ferret Echo Normal Values (Mean)

• LVIDD 11.0 mm
• LVIDS - 6.4 mm
• LVPW - 3.3 mm
• FS - 42
• EPSS - 0