Essentials of Echocardiography Flashcards
what are the normal echocardiographic windows?
right parasternal window
left parasternal windows
what can cause left ventricular outflow tract obstruction?
systolic anterior motions of the mitral valve
left ventricle tumor
what is fractional shortening?
a measure of the difference in size of the left ventricle in diastole and systole
what is the equation for fractional shortening?
FS= (LVIDd-LVIDs)/LVIDd
what is a normal left atrium:aorta ratio in the short axis?
<1.5:1
what can cause abnormal flow velocity or direction on doppler echocardiography?
valvular regurgitation
septal defects
what is doppler frequency shift directly proportional to?
velocity of red blood cells in the direction of the ultrasound beam
what are the doppler modalities?
spectral doppler
color flow doppler
tissue doppler
what does spectral doppler allow?
interrogation of blood flow velocities in specific area of interest
determination of location and timing of turbulence
what is tissue doppler used for?
velocity of myocardial motion
diastolic function
systolic function
left atrium filling pressures
what does spectral doppler continuous wave allow?
recording of higher blood flow velocities
what is a normal short axis LA:Ao?
<1.3:1
should not be able to fit >2-3 aortic areas within the body of the LA
what are some applications of dopper echocardiography?
characterize abnormal flow velocity or direction
identification of turbulent blood flow
estimation of flow volumes
assessment of pressure gradients
evaluation of diastolic dysfunction
estimation of cardiac filling pressures
what is the principle of doppler?
frequency of ultrasound waves is altered in a predictable fashion when they are reflected by a moving target
what must be the angle of the doppler beam in relation to the direction of flow?
must be parallel: <20 degrees difference
