Cardiac Radiology

Lectures 23, 24

What is a normal vertebral heart sum for canine?

9.7 ± 0.5 vertebrae

normal range 8.5-10.5

What is a nomal vertebral heart sum for feline?

7.5 ± 0.3 vertebrae

Explain how to perform a vertebral heart sum.

draw your lines in short and long axis (carina to apex then approximately 90 degree)

take each line and measure parallel to thoracic spine beginning at T4 vertebral body 

count the number of vertebrae caudally

sum your two line measurements 

When you make your line from the carina to apex of the heart, what is the normal proportions for right and left sides?

3/5 on the right

2/5 on the left 

How many intercostal spaces is the cat heart normally on a lateral radiograph?

less than or equal to 2.5 ICS

How big is a feline heart normally on a VD or DV radiograph?

approximately half to two-thirds width of thorax

What part of the heart sits at 11 to 1 o’clock?

aorta

What part of the heart sits at 1 to 2 o’clock?

pulmonary artery

What part of the heart sits at 2 to 3 o’clock?

left atrium

What part of the heart sits at 3 to 5 o’clock?

left ventricle

What part of the heart sits at 5 to 9 o’clock?

right ventricle 

What part of the heart sits at 9 to 11 o’clock?

right atrium

What part of the heart is enlarged in this lateral radiograph?

left atrium

What radiographic changes can we see on a lateral view if there is left atrial enlargement?

straightening of caudo-dorsal heart margin

What radiographic changes can we see on a VD view if there is left atrial enlargement?

splitting of mainstem bronchi

round opacity superimposed over caudal aspect of heart

with severe changes you can see left auricular appendage bulge at 2-3 o’clock on VD 

What part of the heart is enlarged on this lateral radiograph?

left ventricle

What radiographic changes can we see on a lateral or VD/DV view if there is left ventricular enlargement?

may appear radiographically normal

in severe enlargement, heart may elongate

dorsal displacement of the entire thoracic trachea (thoracic inlet to carina)

What part of the heart is enlarged on this lateral radiograph?

right atrium 

Right atrial enlargement is more obvious on which view?

VD

What radiographic change can we see due to right atrial enlargement?

shift apex of heart

What radiographic changes can we see as a result of right ventricular enlargement?

bulging on VD/DV (reverse D pattern)

elevation of apex from sternum on left lateral 

What are common causes of right ventricular enlargement?

hypertrophy most common

heartworm disease

pulmonic stenosis

A 4 month old puppy fell in the pool yesterday and presents today struggling to breathe. What is the predominant pulmonary pattern?

alveolar

A 4 month old puppy fell in the pool yesterday and presents today struggling to breathe. What is your primary differential?

non-cardiogenic pulmonary edema 

A 4 month old puppy fell in the pool yesterday and presents today struggling to breathe. Why si your primary differential not aspiration pneumonia?

because this is a caudo-dorsal alveolar pattern, not ventral

What are causes for non-cardiogenic pulmonary edema?

neurologic (seizures)

severe allergic reaction

advanced uremia

pancreatitis

irritating inhalants

drowing (or near drowning)

List some common acquired cardiac diseases/abnormalities. 

mitral valve insufficiency 

tricuspid valve insufficiency 

heartworm disease

cardiomyopathy 

pericardial effusion 

Define heart failure.

Failure of left or right ventricle of heart affects portion of circulation “upstream” from affected chambers.

Unilateral is most common but can be combined in late disease.

What are radiographic indications of left sided carciac failure/

pulmonary venous congestion (vein dilated, larger than corresponding artery)

pulmonary edema

If you suspect pulmonary edema is due to left sided heart failure, what can you do to confirm?

give a diuretic (lasix)

if edema due to left sided heart failure, there will be a rapid response within 12-24 hours 

What is the radiographic appearance of cardiogenic pulmonary edema in dogs?

interstitial to alveolar pulmonary pattern in caudal lung lobes and perihilar region

pattern is patchy to diffuse

left atrial dilation, pulmonary vein dilation, cardiomegaly

What is the radiographic appearance of cardiogenic pulmonary edema in cats?

there is no typical pattern of cardiogenic edema in cats

often a more patchy pulmonary pattern 

can also have pleural effusion with left-sided heart failure 

What are radiographic indications of right sided heart failure?

hepato-splenomegaly

ascites

pleural effusion

enlarged CVC

What are the four general categories of common acquired cardiac diseases?

valvular

myocardial

heartworm disease

pericardial effusion

Common presentation: cough

middle aged to old small breed dogs 

degenerative disease of atrioventricular valves (nodular, myxomatous changes, usually mitral)

valves fail to close properly 

chronic degenerative valvular disease 

Mitral valve insufficiency can create what on radiograph?

left atrial enlargement with progression to include left ventricular enlargement 

Cough associated with mitral valve insufficiency can be caused by what?

left atrial compression of left caudal lobar bronchus

left sided congestive heart failure results

A 9yo MC Cocker Spaniel mix presents for coughing and exercise intolerance. What is the primary pulmonary pattern?

primarily unstructured interstitial pattern

predominantly in the caudodorsal lungs and perihilar region

left worse than right

A 9yo MC Cocker Spaniel mix presents for coughing and exercise intolerance. Your primary pulmonary pattern is unstructured interstital but what other pattern is present?

focally more severe alveolar pattern 

A 9yo MC Cocker Spaniel mix presents for coughing and exercise intolerance. What can be seen in this radiograph as far as heart features?

left sided cardiomegaly and left atrial enlargement

A 9yo MC Cocker Spaniel mix presents for coughing and exercise intolerance. What is your primary differential?

cardiogenic edema secondary to left sided congestive heart failure 

What can be seen in these cat radiographs?

Nothing, these radiographs are normal

What presenting signs can be associated with feline hypertrophic cardiomyopathy?

murmur, gallop rhythm, severe dyspnea, hind or fore limb paralysis (“saddle thrombus”)

What breed has a hgiher incidence of feline hypertrophic cardiomyopathy?

Maine coon

What radiographic changes can be seen with feline hypertrophic cardiomyopathy?

heart may be normal 

mild to severe left atrial enlargement 

apex often displaced rightward

classic “valentine shaped” heart 

What can be seen on these feline radiographs?

left atrial enlargement

What pulmonary pattern can be seen in this radiograph?

diffuse interstitial pattern

What pattern does feline cardiogenic edema generally present as?

random

patchy

peri-vascular in distribution 

True or false: Feline cardiogenic edema will show a dramatic (rapid) response to treatment.

True

What breeds do we most commonly see canine dilated cardiomyopathy?

large and giant breed dogs (great dane, boxer, doberman)

cocker spaniel

What clinical signs can be associated with canine dilated cardiomyopathy?

dyspnea, tachypnea, pulmonary edema

What radiographic changes can be seen with canine dilated cardiomyopathy?

heart may be normal to severe cardiomegaly

mild to severe left atrial enlargement (may be only change visible)

radiographic presentation varies between breeds

Canine dilated cardiomyopathy is caused by what?

myocardial dysfunction (decreased contractility of ventricle leads to atrial dilation)

Mature heart worms live where? What does this cause?

the right outflow tract 

causes pulmonary arterial intimal thickening —> inflammation and mechanical obstruction

Heart worm disease can present with what clinical signs?

cough, exercise intolerance

Radiographic changes with heartworm disease are related to what?

worm burden

What can be seen in this magnified canine radiograph?

dilated cranial lobar artery due to heartworm disease 

What part of the heart is enlarged in this radiograph?

Main pulmonary artery (bulge at 1:00)

What lung changes can be associated with heartworm disease?

eosinoohilic bronchopneumopathy

pulmonary thromboemboli

unstructured interstitial pattern throughout the lungs

What is the most common cause of pericardial disease?

effusion

What presenting signs can be associated with pericardial disease?

weakness

collapse

pale

What can be seen in this canine radiograph?

pericardial effusion

What are abdominal manifestations of pericardial effusion?

dilated CVC

hepato-splenomegaly 

ascites 

What border description of the heart can be associated with pericardial effusion?

curved caudal dorsal border

What are causes of pericardial effusion?

idiopathic (golden retrievers)

neoplastic (right atrial tumors or chemodectomas)

hemorrhage

infectious

11 month old female kitten presents with 1 day history of lethargy and tachypnea. What is your primary differential?

cardiogenic pulmonary edema, likely due to congenital malformation

What are the four categories of congenital cardiac disease?

valvular stenotic lesions

valvular incompetence lesions

shunting lesions

vascular ring anomalies

How does subaortic stenosis/stenotic aortic valve appear on radiograph?

enlargement of the aortic arch due to turbulent blood flow (11-1 o’clock(

elongation of the left ventricle due to hypertrophy 

What can be seen in these radiographs?

subaortic stenosis/stenotic aortic valve

How does pulmonic stenosis present on radiograph?

dilated main pulmonary artery (1-2 o’clock)

enlargement of right ventricle secondary to hypertrophy

± pulmonary under circulation (small arteries and veins)

What can be seen on this radiograph?

pulmonic stenosis 

What radiographic changes can be associated with pulmonic stenosis?

enlargement of right ventricle secondary to hypertrophy

dilated main pulmonary artery

bulge at 1-2 o’clock

Sometimes on lateral view: apex elevated from sternum, bulge in cranio-dorsal margin of heart

What breed is predisposed to mitral valve dysplasia?

cavlier king charles spaniel

What radiographic changes can be associated with mitral valve dysplasia?

left heart enlargement (left atrium ± left ventricle)

± pulmonary venous congestion

What can be seen in this radiograph?

left atrial enlargement due to mitral valve dysplasia

What can be seen in these radiographs?

mitral valve dysplasia

Shunting lesions almost always shunt in which direction?

left to right (high pressure to low pressure)

What radiographic changes can we see with shunt lesions?

heart may be radiographically normal

look for overperfused lung (congestion/distention of main vessels, increased size and number of peripheral vessels)

progresses to left sided heart failure

A ventricular septal defect is a ___ to ___ shunt. 

left to right 

Ventricular septal defect is usually located where?

in the membranous septum

What breeds do we commonly see affected with a ventricular septal defect?

english bulldog, springer spaniel, cats 

What are radiographic changes assoicated with ventricular septal defect?

often difficult to identify radiorgaphically (use echocardiography)

can see variable heart enlargement, mild pulmonary over circulation

What can be seen in this angiogram?

ventricular septal defect

What connects aorta with pulmonary artery?

ductus ateriosus

What is the “three knuckles” sign?

associated with patent ductus arteriosus but rare

dilation of aortic root, main pulmonary artery (1-2 o’clock), and left auricle (3 o’clock)

What is seen in this magnified radiograph?

three knuckles sign associated with patent ductus arteriosus

What radiogrpahic changes can we see with aptent ductus arteriosus?

generalized cardiomegaly

“three knuckles sign” rare, usually onlt 1-2 bulges

pulmonary over circulation