Radiology, echocardiography Flashcards
What are indications for thoracic radiographs?
- cough
- heart murmurs, abnormal lung sounds
- exercise intolernce
- neoplasia
- dyspnea, tachypnea
- arrhythmias
What is the value of thoracic radiographs for cardiology?
- determine cardiomegaly, vascular status, heart failure, lung changes
Which species are radiographs more diagnostic in?
dogs (in cats may not see change in heart outside–concentric hypertrophic cardiomyopathy but still diagnostic for heart failure in both species)
What is a major problem with radiographs (compromised patient)
can be fatal!
What are the standard positions for radiographs?
right lateral (LATERAL), VD or DV
When in resp cycle should a thoracic radiograph be?
full inspiratory
Why is anesthesia not a good time to do radiographs?
if they are breathing, not breathing in enough, if ventilating not reflective of actual breathing and there is atelectasis
Why would you think the heart is enlarged with expiratory radiograph?
the heart appears big because the lung field is smaller
Why can breed differences cause issues with thoracic radiographs?
smaller barrel chested dogs have more sternal contact. Hard to judge increased sternal contact in a barrel chested dog!. on a VD, the heart appears more on the left hemthorax (associated with left ventricular enlargement but very difficult to judge on a barrel chested dog)
Why might an obese dog appear to have a large heart?
deposition of fat, cannot breath in well, hard to position well
What is the most important view for looking at the heart for dogs for the left atrium?
the lateral because the left atrium sits dorsocaudally and as enlarged it gets bigger over a lung field so can see it.
If coughing or have pulmonary edema have to have left atrial enlargement.
What happens with left ventricular enlargement?
deviation of the trachea
What is the vertebral heart score?
measure vena cava across heart and from bifurcation down the heart and go up to T4 and measure the number of vertebral bodies for each measurement. if greater than 10.5 you have heart enlargement.
How can you get an impression of left atrium enlargement on VD?
the splitting of the bronchi. but often hard to see that.
Why can it be easier to spot early pulmonary edema in VD?
because travelling only through one lung field. stuff is less dense in that area so can see abnormality
How can you detect left ventricular enlarmgenet on VD?
increased heart in left side
How can you detect right atrium and ventricle enlargement?
hard on lateral!!–increased ventricular size appears as more sternal contact but hard to judge in barrel dog. On VD, can detect right atrial enlargement and can detect right ventricular enlargement with the reverse D on VD but barrel chested dogs to some extent all look like that! right sided disease very difficult to spot on radiograph unless a deepchested dog but we rarely deal with primary right sided disease
If you have pulmonary venous congestion what side is affected>
left side (but doesn’t happen that often)
Why is important to know where the pulmonary arteries are?
so you can detect a right sided problem–e.g. heartworm!!!! The changes of heartworm are in the pulmonary arteries
Why is looking at vessels not a reliable tool for heart disease?
can be normal in a dog with heart failure
What does aspiration pneumonia appear as in dogs?
anterioventral distribution with alveolar pattern (not edema because that would be perihilar)
What animals is the bronchial pattern common in ?
older dogs
A generalized interstitial pattern think of
- poor inspiratory
- obese
- cancer, fungus, some forms of penumonia
What is interstitial/alveolar pattern in the perihilar region with left atrial enlargement indicative of?
pulmonary edema and left sided heart failure?
Structures to evaluate with thoracic radiographs?
- heart
- vessels
- lung
- extra-thoracic structures
What must you remember when you look at thoracic radiographs of a dog you suspect has heart disease?
LOOK AT EVERYTHING. e.g. look at everything else first before you look at something you think is wrong
What are indications for echocardiography?
- cardiac dz in cats
- congenital dz
- endocarditis suspects
- early detection of DCM
- pericardial effusion
- arrhythmias without obvious cause
what is the treatment for hypertrophic cardiomyopathy in cats?
nothing–unless atrium starts getting large–echos are useful
Who are endocarditis suspects?
large breed dogs
lab, etc
usually not that cardiac sick, usually systemically ill
Why do you need echo for early detection of DCM?
becuase may not see on radiograph but you will use echo because if diagnose will start treating at that time!
Why is echo useful with pericardial effusion?
may not be evident on radiograph
look for tumor! hemangiosarcoma or heart base mass
What are the types of echocardiography?
2D
M-mode
Doppler
What is the use of M-mode
to detect motion–measure–contractility, lumens
What does doppler tell us?
velocity and direction of blood flow-good for congenital defects etc
What can you see on right parasternal long axis, 4 chamber view
assess wall thickness, mitral valve? etc
What can you see on right parasternal ventricular outflow tract?
look for subaortic stenosis, aortic valves
What is fractional shortening
how much heart muscle changes with diastole vs systole. if too low hypocontractile (may be DCM) and hypercontractile–hypertrophic cardiomyopathy, hyperthyroidism, fever
What can you see on echo with HCM?
large left atrium, small lumen of left ventricle and thick walls of left ventricle
