Cardiology Flashcards
What encloses the heart?
fibroserous pericardial sac
an increase in myocardial mass
hypertrophy
an increase in chamber volume
dilation
an overall increase in the external dimensions of the heart
cardiomegaly
What two structures support the AV valves?
How many cusps do the tricuspid and mitral valves have?
chordae tendineae
T= 3 (dog only 2)
M= 2
What structure unique to the aortic and pulmonic valves is connected to the leaflets and is a fibrous saddle shaped ring?
annulus
Normal or not? Nodules on the free edges of the semilunar valve leaflets?
Normal
nodules of arantius
Normal Anatomy of the valves.
Process of valve closing: describe what the leaflets and the annulus do.
The cardiac skeleton supports the cardiac muscle & valves. Consists of four fibrous rings, fibrous triangle, and fibrous or membranous part of the septum
What is the cardiac skeleton made up of in pigs, cats, dogs, horses, large ruminants?
Dense fibrous CT in pigs & cats
Fibrocartilage dogs
Hyaline cartilage horse
Bone (os cordis) large ruminants*
What is the major blood supply to the heart?
When does the most flow occur?
coronary arteries that branch directly off the aorta
most flow during diastole
What is the dominant pacemaker of the heart?
Where is it located?
SA node
located subepicardially at
junction of cranial vena cava and right auricle
Describe the conduction system of the heart?
abnormalities in rate and rhythm
Dysrhythmias
What is the most common cause of dysrhythmias?
injury to the atrial/ventricular myocytes
also known as the visceral pericardium: Thin layer of mesothelium on elastic fiber-rich
connective tissue
epicardium
When is Atrial natriuretic factor released?
dilation/stretch of the atria
causes increase Na excretion and inhibits renin release
From what layer of the heart as AV valves infoldings of?
endocardium
Can mature cardiac muscle cells divide?
no, limits capability for compensation
Describe the compensatory mechanism for a failing heart?
What limits the extent to which cardiac myocytes can hypertrophy?
Causes of concentric hypertrophy?
Concentric cardiac hypertrophy
(Right side- increase size of moderator band)
Causes for Eccentric hypertrophy
Type of hypertrophy?
Eccentric hypertrophy
Globose heart (wall appear thin even though there has been hypertrophy d/t dilation)
Evidence of cardiac dilation d/t attenuation of papillary muscles and severe subendocardial fibrosis
What may be the best indicator of dilation in the atria?
subendocardial fibrosis
Left sided heart failure
pulmonary congestion/edema
left atrial enlargement
What sequelae of L-sided HF is shown here?
pulmonary edema
What sequelae of L-sided HF is shown?
hemosiderosis
How does the signs of R-sided heart failure manifest differently in horses vs. ruminants vs. dogs vs. cats?
Fibrosis on surface of liver
difference in zonal apperance- bright red from atrophy of cells around portal v. when blood is pooling
dark black- around central v. - backflow of blood- pressure on hepatocytes leads to cell death and darkening from blood buildup
nutmeg liver
Describe the changes in the liver d/t R-side HF?
dilations of sinusoids
congestion of sinusoids
atrophy of hepatocytes around central veins
Sequelae of R-side HF
Which species most likely?
ascites
dog
Sequelae of R-side HF
Which species most likely?
hydrothorax
cat
for what disease is this pathognomonic?
Cor pulmonale d/t HW w/ endarteritis (arrow)
pathognomonic for HW
In developing heart, there are 3 major
arteriovenous communications
Great vessels (Ductus arteriosus)
Between the atria
Between the ventricles
What structure in the heart has a flap that closes at birth to prevent from L to R shunting?
foramen ovale
Causes of atrial septal defects
What happens when there is an atrial septal defect?
What is the arrow pointing to?
What does the star indicate?
What three parts of the embryonic heart make up the ventricular septum?
Membranous portion of the septum derived form the endocardial
cushions
Muscular portion
Downward growth of the conotruncal ridges
Consequences of a VSD?
VSD in membranous portion
VSD in muscular portion
How long does it take DA to close after birth?
5 days
>5d = PDA
PDA
subendocardial hemorrhage
subendocardial mineralization
valves have large, adhering, friable, yellow-to-
gray masses of fibrin termed vegetations
Microscopically – layers of fibrin, numerous bacteria, leukocytes, granulation tissue
DDX?
vegetative endocarditis
valvular endocarditis
A dog presents with this.
uremic endocarditis
An 8 yr old chihuahua presents with this on the mitral valve. DDx?
What are the possible sequelae of endocardiosis?
What is this a possible sequela for?
endocardiosis
Likely species?
Is this a problem?
Hematocysts or lymphocysts
ruminants
no- regress in a couple of months after birth
DDX? A lamb presented with this.
Vit E and Se def
White muscle dz
DDX? Swine
mulberry heart disease
What is the cause of myocardial necrosis from the brain-heart syndrome?
injury to the brain causes
- coronary a. spasm
- excess catecholamines- free radical damage
A cow presented with myocarditis from what type of an infection?
C. chauvoei
A dog presented with this.
myocarditis-Blastomyces dermatitidis
Myocarditis – canine parvovirus 2
What substances when def could lead to cardiomyopathy?
taurine and carnitine
A cat presents with the following.
HCM
A cat presents with heart failure.
HCM
fat cardiomyocytes in different directions (not linear) more fibrosis and stiff
What is the gross & histo appearance of RCM in cats?
A cat presents with the following?
DCM
Excessive moderator band
What condition does this dog likely have?
DCM
subendocardial fibrosis
A wooly coat hereford calf presents to you in heart failure.
cardiomyopathy (Fibrosis, necrosis, mineralization)
hydropericardium
hemopericardium
serous atrophy of pericardial fat
cachexia
foal
DDX? causative agent?
Fibrinous pericarditis
mycoplasma felis
DDX? causative agent?
It’s from a pig
glasser’s dz
fibrinous pericarditis
A cow
Chronic constrictive pericarditis
What primary tumors of the heart in dogs may arise at the heart base?
aortic body (chemodectomas) and ectopic thyroid and parathyroid tumors may arise at heart base in dogs
DDX?
sequelae?
chemodectoma
cor pulmonale
rhabdomyoma
An old dog
lymphoma
