2.2.3: Cardiac radiography Flashcards
Is this an enlarged heart or pericardial effusion?
Pericardial effusion
How would you differentiate between generalised cardiac enlargement and a pericardial effusion?
Ultrasound is very useful to differentiate! (V sensitive)
With a pericardial effusion:
* Whole silhouette is grossly enlarged (not just one side or chamber)
* The heart has a globular appearance
* The outline is distinct because there is no movement
* There will be secondary signs of R-sided heart failure
Enlarged heart or pericardial effusion?
Generalised cardiac enlargement and a possible mass, and ascites in the abdomen
This shows generalised cardiac enlargement
* There is more sternal contact
* There is displacement of the trachea by the enlarged left atrium and left auricular appendage
This is a pericardial effusion
* There is possibly an enlarged heart within this also
* The trachea is being displaced by the heart
* This could be a haemangiosarcoma bleeding within the pericardium
Microcardia
This tends to be seen in hypovolaemic patients
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Left atrium
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Left ventricle
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Aorta
An enlarged left atrium will mean which of the following is more likely to be seen on radiography:
a) more sternal contact with the heart
b) the trachea will be displaced dorsally
b) the trachea will be displaced dorsally
See this example of left sided heart failure:
Describe the findings on this radiograph
- Massively enlarged left atrium that displaces the trachea dorsally
- Alveolar pattern consistent with pulmonary oedema
- This supports a diagnosis of left-sided heart failure
Which of the following is more likely to be seen on radiographs of an animal with right-sided cardiac enlargement?
a) more sternal contact with the heart
b) displacement of the trachea dorsally
a) more sternal contact particularly when the enlargement is to the right ventricle
See this example:
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Left sided enlargment
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Enlargment of the right ventricle
The normal feline heart is the same width as ??? intercostal space when viewed on lateral radiographs.
The normal feline heart is the same width as 2 intercostal spaces when viewed on lateral radiographs.
True/false: in cats, the cardiac silhouette enlarges far before we reach the point of heart failure.
False
By the time the external silhouette of the heart enlarges, the cat is in heart failure.
(In cats, HCM common, meaning that the wall hypertrophies and can reduce the lumen before it expands outwards and increases the cardiac silhouette).
Describe the findings on this radiograph
Atrial enlargment consistent with HCM. Ventricles appear normal.
Describe the findings on this radiograph
- Bronchial pattern starting to develop (precursor to alveolar) as pulmonary oedema develops
- There is increased sternal contact
- The left atrium is subtly enlarged
True/false: tracheal displacement can be seen with cardiac enlargement in heart failure. This feature is more commonly seen in cats than dogs.
False
We see less tracheal displacement with cats compared to dogs because cat hearts are much smaller to start with.
Below is a cat with cardiomegaly
This is:
a) normal
b) abnormal
a) normal
In older cats it is common to find a more horizontal heart with a prominent aortic arch
It is also worth noting that in cat thoraxes everything is very mobile, so the heart may not be in exactly the position expected. Also must remember that you can induce a murmur by pressing too hard on the chest wall.
Describe the radiographic findings
- Alveolar and bronchial pattern due to pulmonary oedema
- Large left atrium displacing the trachea upward
- Increased sternal contact
This is feline cardiac enlargement
Cardiac radiography has limitations. What questions should you ask before diagnosing based on images?
- Is the radiographic quality consistent with the clinical findings?
- Is the quality of the radiograph adequate to permit a confident radiograph diagnosis?
This is:
a) normal
b) abnormal
a) normal - this is a deep chested dog
e.g. GSD, Weimeraner, Doberman
This is:
a) normal
b) abnormal
a) normal
This is a shallow-chested dog e.g. Dachshund, pug, French bulldog
What is the normal vertebral heart score range?
Dogs: 8.5-10.5, average 9.7
Cats: average 8
Remember that breed specific ranges are available
