basic echocardiography wendy blount, dvm nacogdoches tx wendy blount, dvm nacogdoches tx
TRANSCRIPT
Basic EchocardiographyBasic Echocardiography
Wendy Blount, DVMNacogdoches TXWendy Blount, DVMNacogdoches TX
Echo Technique - AnatomyEcho 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
Echo Technique - AnatomyEcho Technique - Anatomy
RV• Conus arteriosus• 3 papillary muscles
LV• 2 papillary muscles
Echo Technique - Physiology
Echo Technique - Physiology
Ventricular filling - volume• 70% passive• 30% atrial contraction
Diastole – time period• First 1/3 - rapid passive filling from atria• Second 1/3 – filling slows (diastases)• Final 1/3 – atria contract
Echo Technique - Physiology
Echo Technique - Physiology
Heart Sounds• HS1
– AV Valves close– Beginning of systole
• HS2– Semilunar valves close– Beginning of diastole
Echo Technique - Physiology
Echo Technique - Physiology
Heart Sounds• HS3 – protodiastolic gallop
– Rapid ventricular filling– First 1/3 of diastole– stiff LV– large diastolic volume
• HS4– Atrial contraction– Last 1/3 of diastole– Stiff LV or 3rd degree heart block
Echo Technique - Physiology
Echo Technique - Physiology
Heart SoundsGallop Rhythms
– HS3?– HS4?– Can’t tell the difference if heart rate
is above 160-180– Just call it a summation gallop
EchocardiographyEchocardiography
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
EchocardiographyEchocardiography
Equipment• Double window with simultaneous
B and M modes• 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
EchocardiographyEchocardiography
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
EchocardiographyEchocardiography
Positioning for 8 standard views• Right lateral recumbency• Cardiac table is nice but not necessary• Sonographer needs a stool or chair• Placement of probe:
– 3rd-6th ICS– Usually 4th-5th ICS– Feel the apical beat, and put your probe
there– Adjust one space forward or back as needed– Rarely move the probe head – just fan and
twist
1. Short Axis – Left Ventricle1. Short Axis – Left Ventricle
• Feel the right apical beat• Point the probe marker cranially• Place the probe at the apical beat• Rotate and fan until papillary muscles
are seen, and the same in size• If you are getting a shadow, try one
intercostal space forward or back
1. Short Axis – Left Ventricle1. Short Axis – Left Ventricle
Abbreviations - Structures• P – pericardium• RV – right ventricle• LV – left ventricle• PPM – posterior papillary muscle• APM – anterior papillary muscle
1. Short Axis – Left Ventricle1. Short Axis – Left Ventricle
Measurements• IVSTDIVSTD - IntraVentricular Septum Diastole• LVIDD - LV Inner Diameter Diastole• LVPWD – LV Posterior Wall Diastole• IVSTSIVSTS - IntraVentricular Septum Systole• LVIDS - LV Inner Diameter Systole• LVPWS – LV Posterior Wall Systole
1. Short Axis – Left Ventricle1. 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 prelood and afterload can affect FS, as
well as myocardial function
1. Short Axis – Left Ventricle1. Short Axis – Left Ventricle
Measurements - Calculated• FS – fractional shortening• >30% in the dog• >40% in the cat• >45% if MR is compensated
1. Short Axis – Left Ventricle1. Short Axis – Left Ventricle
Measurements - Tips• Make sure you don’t include PM in the LFPW
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 Ventricle1. 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 – Apex2. Short Axis – Apex
Structures• Pericardium• May or may not see RV• LV apical lumen
No measurements here
3. Short Axis – Chordae Tendinae3. Short Axis – Chordae Tendinae
Structures• Pericardium• RV• LV • CH - Chordae Tendinae (posterior & anterior)
No measurements here
4. Short Axis – Mitral Valve4. Short Axis – Mitral Valve
Structures• Pericardium• RV• RV Papillary Muscles• LV • MV - Mitral Valve (Posterior & Anterior)
4. Short Axis – Mitral Valve4. 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 Valve5. 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 Valve5. 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 Artery6. 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
Ferret Echo Normal Values (Mean)Ferret Echo Normal Values (Mean)
• LVIDD – 11.0 mm• LVIDS - 6.4 mm• LVPW - 3.3 mm• FS - 42%• EPSS - 0
7. Long Axis – 4 Chamber7. Long Axis – 4 Chamber
Technique• Get short axis LV-PM view• Rotate 90 degrees counterclockwise
7. Long Axis – 4 Chamber7. 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• PVe – Pulmonary Vein
8. Long Axis – LVOT8. Long Axis – LVOT
Technique• Find 4 Chamber view• Angle the “dot” toward the shoulders• Elevate the cord end of the probe
8. Long Axis – LVOT8. 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