Unit 4 Case 3

Question 1

What is Unit 4 Case 3 about?

Answer 1

Mario Moretti, 70 years of age, suffered a head wound and complained of a sore chest. A chest-x-ray was ordered and the inferior mediastinum looked enlarged. A CT scan was done revealing enlargement of the descending aorta. He was given a beta-adrenergic antagonist to manage his thoracic aortic aneurysm. A few weeks later the aneurysm had ruptured. Successful emergency surgery was done and he was discharged.

Question 2

What is an aneurysm?

Answer 2

An aneurysm a dilation of an artery or blood vessel caused by weakness in the vessel wall

Question 3

What are the different types of aneurysm?

Answer 3

There are 3 types of aneurysm

• Saccular
• Fusiform
• Pseudoaneurysm

Question 4

What is a saccular (berry) aneurysm?

Answer 4

A type of true aneurysm, where the dilation of the blood vessel is asymmetrical and is only one side.
-because there is higher pressure on one side of the artery or it is weaker

Question 5

Why are aneurysm’s more common in arteries?

Answer 5

As the blood pressure in arteries is greater than in veins

Question 6

When is the dilation of a blood vessel deemed an aneurysm?

Answer 6

When the diameter of the blood vessel enlarges to become at least 1.5 times larger than the original diameter

Question 7

What are the main 2 classifications of aneurysms?

Answer 7

True aneurysm- where all the layers of the blood vessel dilate
False (Pseudoaneurysm)- where there is a hole in the blood vessel causing blood to leak out, which becomes encased with connective tissue, causing a bulge.

Question 8

What are fusiform aneurysms?

Answer 8

A type of true aneurysm, where the dilation of the blood vessel is symmetrical
-due to the weakness of high pressure in the vessel

Question 9

What is a pseudoaneurysm?

Answer 9

A type of false aneurysm, where there is a hole in the blood vessel causing blood to leak out and become encased by connective tissue, causing a bulge

Question 10

Where do aneurysms most often take place?

Answer 10

around 60% abdominal aorta

around 40% thoracic aorta

Question 11

Why do most abdominal aneurysms take place below the renal arteries?

Answer 11

Less elastin so vessels are weaker

Question 12

How is an aneurysm caused?

Answer 12

Walls of a blood vessel weaken, meaning it cannot control the blood pressure

Question 13

How can Laplace’s law explain an aneurysm?

Answer 13

Increased blood pressure causes an increase in diameter. This increases the tension
-causing a positive feedback loop that leads to the continued growth of the aneurysm

Question 14

Can your chances of an aneurysm be affected by genetics?

Answer 14

There are some genetic disorders (Marfan’s syndrome, Ehlers-Danlos syndrome) that weaken the walls of the blood vessels, therefore increase chances of an aneurysm

Question 15

What is an intact aneurysm?

Answer 15

When the aneurysm hasn’t ruptured. Normally doesn’t have symptoms unless pressing on other organs or vessels e.g on the aortic valve preventing it from closing

Question 16

What are the consequences of an aneurysm rupturing?

Answer 16

Blood leaks out, causing internal bleeding, decreasing blood flow down the vessel leading to ischemia in cells (decreased blood flow to cells )

Question 17

What is the mechanism of action of beta-adrenergic antagonists?

Answer 17

Also known as beta-blockers. These bind to beta-adrenoceptors and thereby block the binding of norepinephrine and epinephrine to these receptors. This inhibits the sympathetic effects of these receptors, making the heartbeat slower and with less force to reduce blood pressure and help control the aneurysm

Question 18

What is pericardial effusion?

Answer 18

Excess fluid in the space around the heart (pericardium). This can put pressure on the heart

Question 19

What is pericardial tamponade?

Answer 19

When the tough membrane can no longer stretch and accommodate, thereby exerting pressure on the heart

Question 20

What are the risk factors for an aneurysm?

Answer 20

• Age -most common after 65
• Smoking
• High blood pressure
• Plague build-up in arteries (atherosclerosis)
• Marfan’s syndrome (and other related genetic syndromes)
• Bicuspid aortic valve
• Obesity

Question 21

What is the difference between an emergency and elective surgery?

Answer 21

Elective surgery- is scheduled in advance
Emergency surgery- must be performed without delay
All based on urgency

Question 22

What are the types of surgery to treat an aneurysm?

Answer 22

Open thoracic surgery-

Endovascular surgery-

Question 23

What are the risk factors for thoracic and abdominal aneurysms?

Answer 23

High blood pressure
High cholesterol
Smoking
Family history

Question 24

What are some approaches in place to try to reduce the incidence of thoracic and abdominal aneurysms?

Answer 24

Strategies to decide overweight/obesity - like the sugar tax
Strategies to reduce smoking- packaging

Question 25

What is the short term regulation of decreased blood pressure/volume?

Answer 25

Sympathetic activation- adrenal glands release epinephrine and norepinephrine

• this increases cardiac output and peripheral vasoconstriction
• increasing blood pressure

Question 26

What is the long term regulation of decreased blood pressure/volume?

Answer 26

Kidneys produce renin which leads to the secretion of aldosterone
-this increases cardiac output and peripheral vasoconstriction and therefore increases blood pressure
Kidneys also produce erythropoietin, which increases red blood cell formation which increases blood volume

Question 27

What are chronotropic drugs?

Answer 27

Chronotropic drugs are drugs that affect the heart rate by affecting the electrical conduction system of the heart.
With positive chronotropic drugs increasing heart rate and negative chronotropic drugs decreasing heart rate

Question 28

What are inotropic drugs?

Answer 28

Inotropic drugs are drugs that change the force of your hearts contractions
With positive inotropic drugs increasing force of contraction and negative inotropic contraction decreasing the force of contraction

Question 29

What is the vasovagal syncope

Answer 29

This is when you faint at the sight at the sight of blood due to a drop in blood pressure