POC Echo Flashcards
Name the four main POC Echo views
Right parasternal short axis at LV papillary; Right parasternal short axis view at heart base; Right parasternal 4 chamber long axis view; Right parasternal LV outflow tract view
What two ways can a global assessment of left ventricular contractility be assessed?
Qualitative “eyeball” assessment or quantitative assessment by fractional shortening or ejection fraction
Fractional shortening equation (%FS):
(LVIDd - LVIDs / LVIDd) x 100
What is the normal %FS range?
28-45% in dogs
30-50% in cats
FS% below ____ is suggestive of severe myocardial systolic failure?
Below 20%
FS% above ____ is considered hyperdynamic LV function
Above 55%
Especially in human ICUs, most if not all patients with septic shock experience what kind of LV changes?
LV hypokinesis and LV dilation
Sepsis induced myocardial depression is a global (systolic and diastolic) biventricular dysfunction that can be
Reversible
Normal fractional area change
30-60%
Normal ejection fraction
55-75%
Normal intra-cardiac pressures of RA, LA, RV, LV
5, 10, 25, 125
Simplified Bernoulli equation and what it tells you
Pressure gradient = 4x V2
Estimation of pressure from velocity
As the speed of a moving fluid increases, the pressure within the fluid decreases
In human ICUs, the two most common causes of right heart failure secondary to primary lung disease
Massive pulmonary embolism, ARDS
(other causes include sepsis, high levels of PEEP and increased pulmonary vascular resistance due to chronic lung disease)
Common acquired causes of right-sided heart failure in the dog? (5)
Heartworm disease
Other causes of pulmonary hypertension
Neoplasia
Valvular heart disease
Cardiomyopathy
Young dog congenital diseases that cause RV dysfunction?
Pulmonic stenosis
Tricuspid valve dysplasia
What is TAPSE?
Tricuspid Annular Systolic Excursion
A technique assessing RV function
Obtained in MMode in left-sided apical four chamber view
Measures the distance moved by the TV annulus from end diastole to end systole
TAPSE is reduced with RV systolic dysfunction
Why does positive pressure ventilation result in decreased preload and subsequently decreased aortic velocities?
Decreases venous return during inspiration
Studies in humans have shown that magnitude of respiratory variation of _________________________ measured by pulse wave Doppler at the aortic annulus is superior to static measurements of LV end diastolic area to predict fluid responsiveness.
peak aortic velocity
In one study of humans with septic shock, an aortic pulse variation of >____ predicted a fluid responsive state.
> 12%
A fluid responsive animal will have an obviously small caudal vena cava with >______ respiratory fluctuation
> 50-60%
An animal with severely elevated RA pressures will have a dilated vena cava that fluctuates <________ with respirations
<25-30%
And is usually accompanied by dilated hepatic veins and ascites, +/- GB halo sign
