Pathology of the Cardiovascular System Pt 1 Flashcards
What is the function of the cardiovascular system?
What are the compensatory mechanisms that are available to mantain cardiac function? 4
◦ Heart has ability to increase in size if there is increase in requirements.
◦ Whenever there is any type of problem affecting the cardiac system, there is compensatory mechanisms.
Label the parts of the heart indicated in this image:
A.) Pulmonary Valve
B.) Tricuspid Valve
C.) Aortic Valve
D.) Mitral Valve
Which side i the left in this image
Left Ventricle is 5x size of right since it does more work/ more powerful
What does the right side do to the blood?
What are characteristics of cardiac muscle?
Striations with central nuclei, Z bands
What issues can affect cardiomyocytes?
- Fatty degeneration (can cause atrophy)
- Lipofuscinosis (presence of lipofuscin granules that can be found close to nuclei) Sometimes you can see it in heart of animal that is cachectic. (Wear and tear pigment)
- Vacuolar degeneration
- Fatty infiltration
- Myocytolysis (partial loss of contractile proteins, sarcomeres)
- Neoplasia
- Necrosis: Cell death
Which of the issues with cardiomyocytes are reversible?
- Fatty degeneration (can cause atrophy) -> reversible
- Vacuolar degeneration -> reversible
- Fatty infiltration -> reversible
- Myocytolysis (partial loss of contractile proteins, sarcomeres)-> Reversible
Which of the issues with cardiomyocytes are irreversible?
- Lipofuscinosis (presence of lipofuscin granules that can be found close to nuclei)-> irreversible will happen to everyone. Sometimes you can see it in heart of animal that is cachectic. (Wear and tear pigment)
- Neoplasia -irreversible
- Necrosis: Cell death -> irreversible
What occurs if there is preservation of the basement membrane occurs with cardiomyocytes? How does it differ to skeletal muscle?
Preservation of basement membrane in skeletal muscle it can regenerate.
If this happens in cardiac tissue, fibroblasts deposition and colleges deposition/ scar will replace instead. There is some degree of regeneration, but for practical purposes, no cardiac Myocyte regeneration.
Heart damage = Loss of Cardiac myocytes -> Scar
TRUE or FALSE: An animal with history of a heart attack is less susceptible to heart failuure since they have a scar in cardiac tissue.
FALSE
* Someone who has had a heart attack is more susceptible for heart failure since they have scar in cardiac tissue from the heart attack (cardiac myocyte damage)
What is the ratio of thickness of Right ventricle to left ventricle?
L ventricle is larger than right ventricle.
Thickness is 1: 3-4 in regards to right and left ventricle.
In large animal medicine, what is the assumption if the ventricular wall ratio is 1:3 or 1:4 ( R : L)?
The assumption is that there was not a cardiac issue
What is the pathway of blood from the placenta to the umbilical arteries?
Oxygenated blood is carried to fetus from umbilical vein/ The deoxygenated blood returns through the 2 umbilical arteries.
What can happen if the bypasses that are open in fetal development remain open instead of closing?
If these bypasses that are specific to fetus remain open instead of closing, it is considered a congenital abnormality.
Fetal liver is small and is not being utilized for toxin filtration, so level of blood going to the liver is less than it is in adult animals.
If they still have a patent ductus arteriosis you can have encephalitis.
Lungs in fetus non functional, so there is communication between atria, so oxygenated blood coming from caudal vena cava goes right to the left side. Only a small amount of blood will be mixed with deoxygenated blood.
Foremen ovale
What is seen in this image? What is the cause?
Common change that is visible.
* Gelatinous yellow appearance of coronary groove.
* Fat of coronary groove is abnormal looking
* This indicates an animal in poor nutritional state, due to dental, illness, GI issues, starvation.
* Indicates very little fat deposition.
◦ Areas of fat mobilization
What is seen in this image? What is the cause? When is a typical time this is seen?
Petechia, ecchymosis
Terminal hypoxia can result in petechia,
* Petechia noted on coronary groove.
* This is indicates that animal was anoxic, hypoxic, or sepsis
* This can be seen in cows after slaughter, and normally did not have this before going into slaughterhouse.
◦ Animals are stunned, and then they are hanged to bleed them after cutting spinal cord, they take some time to die so there is terminal hypoxia.
What is cardiac syncope?
- Cardiac syncope – acute onset of cardiac failure causing collapse and unconsciousness (abnormal heart rhythm, defective heart valves etc.).
What is Congestive heart failure?
- Congestive heart failure (CHF): Develops slowly from gradual loss of cardiac output due to pressure or volume overload or myocardial injury.
Which is slower to develop: Congestive heart failure or cardiac syncope?
Congestive heart failure
What is wrong with this bull? What is this a manifestation of? What is the pathogenesis?
Brisket edema -> manifestation of chronic cardiac failure.
* Swelling in area of brisket, presence in cattle with high altitude disease/ high mountain disease.
* Pathogenesis: High altitude air is very light/ very little o2, to compensate, heart has to work harder and pump more blood into lungs to be oxygenated and causes pulmonary hypertension, which leads to congestion/ heart failure ( from increased vascular resistance)
What animals may have pulmonary hypertension ? What extracardiac lesion can be seen with these patients with chronic congestion?
- Pulmonary hypertension: animals that have recovered from severe bouts of pneumonia. Areas of the lung necroses and was replaced by connective tissue. This places pressure on the vasculature and causes congestion/ hypertension. Increased hydrostatic pressure, right side will compensate, but when myocardium increases to a certain size their is ischemic injury. Liver is right there, if there is stagnation of blood in caudal vena cava, this blood will cause chronic hepatic congestion, and this will cause** nutmeg liver. **
What is seen in this image?
Heifer, idiopathic pulmonary hypertension leading to CHF
How can pulmonary fibrosis lead to right sided heart failure? What can be seen in these animals?
- Pulmonary Fibrosis -> Pulmonary hypertension -> Chronic hepatic Congestion -> Right Sided Heart Failure.
- Seen: Pulmonary edema, ascites
True or False: Left sided heart failure is characterized by acites
FALSE: Right sided heart failure is characterized by ascites.
How does congestion cause ascites? What is another differential for ascites?
Congestion backs up to the veins -> causing congestion, and ascites
DDX: Hypoprotienemia is another example)
What are we looking for in a post mortem exam of the heart?
- Comparison of Left and right cardiac wall to make sure ratio is correct.
- Look at valves, make sure they are normal
- Make sure that there is no communications between the atria or ventricles
- Size of aorta/ pulmonary artery -> make sure there is no narrowing
- Looking for gross lesions like petechiae, ect.
Is this valve normal or abnormal?
Normal ( thin)
Is this valve normal or abnormal?
Normal (thin)
What must you look for when opening the heart and use caution not to damage when opening?
Cordae tendinae
What are you looking for with the cordae tendinae? When may this issue occur?
Need to look for cordae tendonare rupture. Can happen to people who have car accidents and they hit steering wheel and impact can cause rupture. You can see it in animals with trauma, endocarditis, ect.
What are the congenital abnormalities associated with the heart?
Will congenital abnormalities present at birth? What may indicate them to us?
May take time for these to present. We need to be looking at this when looking at small animals.
* cyanosis, poor condition, poor growth, ect are all examples of things to look for congenital abnormalities
What is seen in this image? What is important to note about it?
Valvular hematocyst -> usually don’t cause symptoms. Regress with age.
How does cardiomyocytes receive nutrients after birth? What about with fetal life? What can be found at these locations where valves were?
No blood vessels within valves after birth. They get nutrients/ oxygen from adjacent osmosis. In fetal life, their are vessels that send nutrients to the heart. This is where these hemacysts grow
What is the tetrology of fallot?
Tetralogy of Fallot: VSD, Overriding aorta (dextroposition of the aorta), pulmonic stenosis, -> right ventricle hypertrophy.
What breeds are predisposed to having tetrology of fallot?
Inherited in Keeshonds, also common in English bulldogs
What is the most common cardiac abnormalities in human babies?
tetrology of fallot
Known as “blue babies”
What is occuring in this picture (circled in green) what is this likely a consequence of?
What is seen in this image? What is indicated by the blue arrows? What is indicated by the green arrows? What is the resulting compensatory mechanism?
What is occuring in this image? What is the outcome of animals with this issue?
This is tricuspid dysplasia (Valvular insufficiency). This is not compatible with life, most animals are born dead.
What is the outcome usually of tricuspid dysplasia? What animals are usually affected? Is this common?
Tricuspid dysplasia usually not compatible with life -> born dead
-> more in cats, but can see in all other animals. Rare overall
What is a ventricular septal defect?
Opening between ventricles. Depending on size of defect will cause the severity of signs.
What is the issue with a ventricular septal defect?
-> left ventricle is more powerful, blood moves from left to right through the defect, but then you scan see it with exercise that they have intolerance. They also will have ventricular overload on the right side since their is increased blood volume/ pressure. This will cause right ventricular hypertrophy and then congestive heart failure. You can see cyanosis in the animals when the blood moves from right to left due ton the hypertrophy.
What is seen in this image?
Ventricular Septal Defect
You have a calf who has stunted growth, a heart murmur on ascultation, and a valvular hematocyst. The calf developed clinical signs of heart failure and exercise intolerance, and decided to pursue humane euthanasia. Durring the necropsy you find the following: (see image)
What was this calves problem
Ventricular septal defect