Right parasternal short axis view at the level of left atrium and aorta (‘Mercedes Benz’) Measurement on frozen B-mode image Measurement taken during diastole (just before QRS on ECG) Measurements taken: LA Diam + Ao Diam (machine will calculate LA:Ao for you) Lines should be drawn through middle of aortic valve leaflets and continued through left atrium in a straight line Normal value - <1.5 in normal dog Increased value in left atrial enlargement (disease like Mitral regurgitation)
FS (Fractional shortening) Right parasternal short axis view at level of chordae tendinae (Mushroom view) Measurement on frozen M-mode image 3 measurements taken during diastole and 3 during systole (6 total) Diastole (just before QRS on ECG) - IVSd (Interventricular septum at end diastole) - LVIDd (Left ventricular internal diameter at end diastole) - LVPWd (Left ventricular posterior wall thickness at end diastole) or LVFWd (Left ventricular free wall thickness at end diastole) – depends on if human machine Systole (at nadir of septal motion – when ventricular diameter narrowest) - IVSs (Interventricular septum at end systole) - LVIDs (Left ventricular internal diameter at end systole) - LVPWs (Left ventricular posterior wall thickness at end systole) or LVFWs (Left ventricular free wall thickness at end systole) – depends on if human machine All measurements are taken from leading edge to leading edge (see below) Machine will calculate Fractional shortening Normal value - >25% in normal dog (breed variations!) Decreased in DCM (heart contracting poorly during systole)
EF (Ejection fraction) Right parasternal long axis view (4 chamber view) Measurement on frozen B-mode image Simpson’s rule used to evaluate left ventricular volume 2 measurements made during diastole and 2 measurements taken during systole Diastole - LVLd (Left ventricle length during diastole) - LVAd (Left ventricle area during diastole) Systole - LVLs (Left ventricle length during systole) - LVAs (Left ventricle area during systole) Machine will calculate Ejection fraction (will also display EDV and ESV – End diastolic volume and End systolic volume) Normal value - >50% in normal dog Decreased in DCM (heart contracting poorly during systole)