Basic Echocardiography Wendy Blount, DVMNacogdoches TX
Echo Tech echnique Anatomy Tricuspid valve Mitral valve • Septal leaflet • Leaflets are less • Parietal leaflet distinct Pulmonic Valve Aortic Valve • Right cusp • Right cusp • Left cusp • Left cusp • Intermediate cusp • Septal cusp
Echo Tech echnique Anatomy RV• Conus arteriosus • 3 papil ary muscles LV• 2 papil ary muscles
Echocardiography Equipment• Transducer – smal footprint • Fanshaped beam or sector • High frequency for smal animals • Low frequency for large animals • Machines range from 2.510 Mhz • 57 MHz wil work fine for most dogs and cats for echo
Echocardiography Equipment • Double window with simultaneous B and M modes (video) • Can do measurements on Bmode or Mmode • 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 – 0.010.02 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. Sh Short Axis s – – Left Ve V n entricle • Fan from base to apex, until you have just passed the mitral valve, and the LV papil ary 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. Sh Short Axis s – – Left Ve V n entricle Abbreviations – Structures• P – pericardium• RV – right ventricle• IVS – intraventricular septum• LV – left ventricle• PPM – posterior papil ary muscle• APM – anterior papil ary muscle
1. Sh Short Axis s – – Left Ve V n entricle Measurements• IVSTd – IntraVentricular Septum Diastole• LVIDd – LV Inner Diameter Diastole• LVPWd – LV Posterior Wal Diastole• IVSTs – IntraVentricular Septum Systole• LVIDs – LV Inner Diameter Systole• LVPWs – LV Posterior Wal Systole
1. Sh Short Axis s – – Left Ve V n entricle Measurements• IVSTd = IVSd = VSd• LVIDd = LVd = LVLd• LVPWd = LVFWd = LVWd • IVSTs = IVSs = VSs• LVIDs = LVs = LVLs• LVPWs = LVFWs = LVWs
1. Sh Short Axis s – – Left Ve V n entricle 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 wel as myocardial function
1. Sh Short Axis s – – Left Ve V n entricle Measurements – Calculated• FS – fractional shortening• AKA shortening fraction (SF) – >30% in the dog– >40% in the cat– >45% if MR is compensated
1. Sh Short Axis s – – Left Ve V n entricle 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 wil be artifactual y smal– And LVPW will be artifactual y thick
1. Sh Short Axis s – – Left Ve V n entricle 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. Sh Short Axis s – – Apex Structures• Pericardium• May or may not see RV• LV apical lumenNo measurements here
3. Sh Short Axis s – – Chordae Tendinae ae Structures• Pericardium• RV• LV • CH – Chordae Tendinae (posterior & anterior)No measurements here
4. Sh Short Axis s – – Mitral Val alve ve Structures• Pericardium• RV• RV Papil ary Muscles• LV • MV – Mitral Valve (Posterior & Anterior)
4. Sh Short Axis s – – Mitral Val alve ve 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 smal dogs and cats
5. Sh Short Axis s – – Aortic c Val alve ve Structures• RVOT – Right Ventricular Outflow Tract• TV – Tricuspid Valve• PV – Pulmonic Valve• Ao – Aortic Valve• LA – Left Atrium
5. Sh Short Axis s – – Aortic c Val alve ve 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. Sh Short Axis s – – Pulmonar ary 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 er Technique• Get short axis “mushroom” view• Rotate 90 degrees counterclockwise
7. Long Axis – 4 Chamber er Structures• RV – Right Ventricle• RA – Right Atrium – difficult to view completely• TV – Tricuspid Valve• LV – Left Ventricle• LA – Left Atrium• MV – Mitral Valve, PM – papil ary muscle
7. Long Axis – 4 Chamber er 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 • FS – >40% • LVIDd – 10-21 mm • EPSS – 0-3 mm • LVPWd – 3-6 mm • EF – >70% • IVSTs – 4-9 • LA:Ao – 0.8-1.4 • LVIDs – 4-11 mm • RVIDd – 3-7 mm • LVPWs – 4-10 mm • RVWd – <3 mm • Aos – 6-12 mm• LAd – 7-15 mm (form)
Ferret Echo Normal Values (Mean) • LVIDD – 11.0 mm• LVIDS – 6.4 mm• LVPW – 3.3 mm• FS – 42%• EPSS – 0
