Basic Echocardiography
Wendy Blount, DVM
Nacogdoches TX
Echo Technique - Anatomy
Tricuspid valve
• Septal leaflet
• Parietal leaflet
Mitral valve
• Leaflets are less
distinct
Pulmonic Valve
• Right cusp
• Left cusp
• Intermediate cusp
Aortic Valve
• Right cusp
• Left cusp
• Septal cusp
Echo Technique - Anatomy
RV
• Conus arteriosus
• 3 papillary muscles
LV
• 2 papillary muscles
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
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
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)
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)
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
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
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
1. Short Axis – Left Ventricle
Measurements
• IVSTd = IVSd = VSd
• LVIDd = LVd = LVLd
• LVPWd = LVFWd = LVWd
• IVSTs = IVSs = VSs
• LVIDs = LVs = LVLs
• LVPWs = LVFWs = LVWs
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
1. Short Axis – Left Ventricle
Measurements - Calculated
• FS – fractional shortening
• AKA shortening fraction (SF)
– >30% in the dog
– >40% in the cat
– >45% if MR is compensated
1. Short Axis – Left Ventricle
Measurements - Tips
• Make sure you don’t 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
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
2. Short Axis – Apex
Structures
• Pericardium
• May or may not see RV
• LV apical lumen
No measurements here
3. Short Axis – Chordae Tendinae
Structures
• Pericardium
• RV
• LV
• CH - Chordae Tendinae (posterior & anterior)
No measurements here
4. Short Axis – Mitral Valve
Structures
• Pericardium
• RV
• RV Papillary Muscles
• LV
• MV - Mitral Valve (Posterior & Anterior)
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
5. Short Axis – Aortic Valve
Structures
• RVOT – Right Ventricular Outflow Tract
• TV – Tricuspid Valve
• PV – Pulmonic Valve
• Ao – Aortic Valve
• LA – Left Atrium
5. Short Axis – Aortic Valve
Measurements
• Ao – at largest dimension (systole)
• LA – at largest dimension (diastole)
• LA:Ao –
– 0.8 to 1.3 in dogs
– 0.8 to 1.4 in cats
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
7. Long Axis – 4 Chamber
Technique
• Get short axis “mushroom” view
• Rotate 90 degrees counterclockwise
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
7. Long Axis – 4 Chamber
Video
8. Long Axis – LVOT
Technique
• Find 4 Chamber view
• Angle the “dot” toward the shoulders
• Elevate the cord end of the probe
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
8. Long Axis – LVOT
Video
Normal Dog Video
Dog RV Measurement Values
• RVWd – less than LVWd
• RVIDd – 1/3 or less of LVIDd
(handout)
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 - >40%
EPSS - 0-3 mm
EF - >70%
LA:Ao – 0.8-1.4
RVIDd - 3-7 mm
RVWd - <3 mm
(form)
Ferret Echo Normal Values (Mean)
•
•
•
•
•
LVIDD – 11.0 mm
LVIDS - 6.4 mm
LVPW - 3.3 mm
FS - 42%
EPSS - 0