Pathology of Ischemic CV Disease Flashcards
Name the most common cause of ischemic heart disease
90% of ischemic heart disease is caused by obstructive coronary atherosclerosis with reduced coronary blood flow.
What are some of the clinical manifestations of insufficient blood supply to the heart?
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.
What are the 2 types of plaques in vessels?
1) Stable Plaques-thickened caps
2) Vulnerable Plaques-thin caps
What are the differences between stable and vulnerable plaques?
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.
What is the pathogenesis of myocardial infarction?
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.
Where do MIs usually start, and how do they progress?
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.
T or F?
Ischemia due to hypoxia is worse than ischemia due to hypoxia and low blood supply
False.
This is obvious, but seemed to be pointed out as a key point in the PDF.
What’s the difference between a subendocardial and a transmural infarction?
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
What vessel is most commonly involved in MI?
The left anterior descending artery. These infarcts involve the anterior and apical LV as well as the anterior 2/3 of the septum
What area of the heart would be effected if there is an occlusion of the left circumflex artery?
The lateral left ventricle wall
What area of the heart would be effected if the right coronary artery is occluded?
The posterior left ventricle and septum.
T or F?
Reperfused infarcts are typically hemorrhagic
True
What type of hypertrophy does the pressure overload state associated with hypertension cause in the heart?
Concentric hypertrophy
Which type of hypertension is most common, and what does hypertension predispose you to?
Primary (idiopathic) is most common. It predisposes you to athersclerosis.
What are the common causes of Cor Pulmonale and what effect does it cause on the heart?
Common causes: COPD, pulmonary vessel diseases, or disorders effecting chest movement.
Effect on heart: Right ventricular hypertrophy due to pulmonary hypertension
Define aneurysm
Aneurysms are localized congenital or acquired dilations of a vessel that occur secondary to the weakening of a wall
Where do Berry aneurysms (congenital) occur, and what are some of the symptoms?
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.
Briefly describe the pathology of an atherosclerotic aneurysm.
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.
T or F?
Athersclerotic aneurysms typically occur in the lower abdominal aorta superior to the renal arteries
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.
What happens in aortic dissection?
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.
List some of the clinical features as well as predisposing factors of aortic dissections.
Clinical features: sudden severe pain radiating to the back, unequal pulses, shock.
Predisposing factors: Hypertension, Connective Tissue disorders (ie Marfans)
When is ventricular rupture most likely to happen following an MI?
2-10 days
What percentage of sudden cardiac death does ischemic heart disease account for?
75-90%
What is the general pathophysiology of vasculitis?
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.
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?
Diagnosis: Giant Cell Arteritis (Temporal Arteritis)
Treatment: Corticosteroids
*this is the most common arteritis, characterized by granulomatous vasculitis
Best way to differentiate between Polyarteritis nodosa and Kawasaki’s disease? (both are medium vessel vasculitis)
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.
In general, what factors determine the classification of vasculitis?
The size of the vessels involved (Large, Medium, Small), anatomic site, histological characteristics and clinical manifestations.
