Pathology of Ischemic CV Disease

Question 1

Name the most common cause of ischemic heart disease

Answer 1

90% of ischemic heart disease is caused by obstructive coronary atherosclerosis with reduced coronary blood flow.

Question 2

What are some of the clinical manifestations of insufficient blood supply to the heart?

Answer 2

1) Angina Pectoris
2) Acute Myocardial Infarction
3) Chronic Ischemic Heart Disease (blockage that either leads to acute MI or multiple small ischemic events). This results in myocyte replacement by fibrous tissue, leading to a loss of contractility.

Question 3

What are the 2 types of plaques in vessels?

Answer 3

1) Stable Plaques-thickened caps
2) Vulnerable Plaques-thin caps

Question 4

What are the differences between stable and vulnerable plaques?

Answer 4

Stable-thick fibrous cap.

Vulnerable-thin cap that is vulnerable to stress. Increased plaque inflammation that leads to vascular remodeling. Vaso vasorum neovascularization that leads to intra-plaque hemorrhage.

Question 5

What is the pathogenesis of myocardial infarction?

Answer 5

You get an irreversible necrosis of myocytes. This is usually caused by a thrombus that interacts with a ruptured plaque which then blocks blood supply and causes some of the heart tissue to die.

Question 6

Where do MIs usually start, and how do they progress?

Answer 6

MIs typically start in the subendocardium since this is furthest from blood supply. The infarct then spreads towards the epicardium over the next few hours.

Question 7

T or F?

Ischemia due to hypoxia is worse than ischemia due to hypoxia and low blood supply

Answer 7

False.

This is obvious, but seemed to be pointed out as a key point in the PDF.

Question 8

What’s the difference between a subendocardial and a transmural infarction?

Answer 8

Transmural is more common. Transmural involves the full thickness of the wall, caused by a thrombus occluding the coronary artery.

Subendocardial is only in the inner third of the endocardium, usually due to hypoperfusion of the heart

Question 9

What vessel is most commonly involved in MI?

Answer 9

The left anterior descending artery. These infarcts involve the anterior and apical LV as well as the anterior 2/3 of the septum

Question 10

What area of the heart would be effected if there is an occlusion of the left circumflex artery?

Answer 10

The lateral left ventricle wall

Question 11

What area of the heart would be effected if the right coronary artery is occluded?

Answer 11

The posterior left ventricle and septum.

Question 12

T or F?

Reperfused infarcts are typically hemorrhagic

Answer 12

True

Question 13

What type of hypertrophy does the pressure overload state associated with hypertension cause in the heart?

Answer 13

Concentric hypertrophy

Question 14

Which type of hypertension is most common, and what does hypertension predispose you to?

Answer 14

Primary (idiopathic) is most common. It predisposes you to athersclerosis.

Question 15

What are the common causes of Cor Pulmonale and what effect does it cause on the heart?

Answer 15

Common causes: COPD, pulmonary vessel diseases, or disorders effecting chest movement.

Effect on heart: Right ventricular hypertrophy due to pulmonary hypertension

Question 16

Define aneurysm

Answer 16

Aneurysms are localized congenital or acquired dilations of a vessel that occur secondary to the weakening of a wall

Question 17

Where do Berry aneurysms (congenital) occur, and what are some of the symptoms?

Answer 17

Berry aneurysms occur at the bifurcation of cerebral vessels. They are most common cause of subarachnoid hemorrhage, may present with sudden severe headaches, and may be associated with polycystic kidney disease.

Question 18

Briefly describe the pathology of an atherosclerotic aneurysm.

Answer 18

The atherosclerosis compresses the wall of the vessel and makes the media weaker. Inflammation promotes degradation of the ECM, which makes the vessel wall even more weak, predisposing it to aneurysm and possible dissection.

Question 19

T or F?

Athersclerotic aneurysms typically occur in the lower abdominal aorta superior to the renal arteries

Answer 19

False

They typically occur in the lower abdominal aorta INFERIOR to the renal arteries.

The renal arteries create turbulence below which promotes atherosclerosis and makes aneurysm development more likely.

Question 20

What happens in aortic dissection?

Answer 20

Blood dissects into the media of a vessel following an intimal tear. The blood can then tear back through the media back into the lumen or move externally and hemorrhage into different cavities in the body.

Question 21

List some of the clinical features as well as predisposing factors of aortic dissections.

Answer 21

Clinical features: sudden severe pain radiating to the back, unequal pulses, shock.

Predisposing factors: Hypertension, Connective Tissue disorders (ie Marfans)

Question 22

When is ventricular rupture most likely to happen following an MI?

Answer 22

2-10 days

Question 23

What percentage of sudden cardiac death does ischemic heart disease account for?

Answer 23

75-90%

Question 24

What is the general pathophysiology of vasculitis?

Answer 24

In vasculitis you have a narrowing of the lumen due to inflammation of the blood vessel. This narrowing can lead to ischemia, fibrosis, or aneurysm formation. It’s suspected that immune complexes are depositing in the vessels, could be an immune response to the endothelial lining itself.

Question 25

An old woman comes in with headaches, tenderness near her temporal artery, and vision loss. What is the most likely diagnosis and how should you treat her?

Answer 25

Diagnosis: Giant Cell Arteritis (Temporal Arteritis)

Treatment: Corticosteroids

*this is the most common arteritis, characterized by granulomatous vasculitis

Question 26

Best way to differentiate between Polyarteritis nodosa and Kawasaki’s disease? (both are medium vessel vasculitis)

Answer 26

Polyarteritis nodosa: poly means many, it attacks many different organs (the arteries involved with those organs) including kidneys, GI tract, heart.

Kawasaki’s Disease: Targets coronary arteries of kids. K for kawasaki, K for kids.

Question 27

In general, what factors determine the classification of vasculitis?

Answer 27

The size of the vessels involved (Large, Medium, Small), anatomic site, histological characteristics and clinical manifestations.