Pathology of the Cardiovascular System 1 Flashcards
(105 cards)
Atherosclerosis
the process of narrowing within the arteries due to a buildup of fatty plaques over time
Atheroma
fatty plaque deposits consisting of an outer firm shell with a soft inner fatty core.
Ischaemic heart disease
When the coronary arteries become narrowed, blood flow and oxygen supply to the myocardium is reduced
Ischaemia
inadequate blood supply
Chest pain resulting from ischeamic heart disease
angina
Most common symptoms of stable angina
pain or a feeling of discomfort or tightness in the chest, which can often spread to the jaw, back, shoulders and arms
The pain is usually worse on exertion / stress (myocardial demand is higher in these conditions and the heart does not receive enough blood) and relieved after a few minutes on resting.
Shortness of breath is also a common symptom
Risk Factors for IHD:
- Diabetes
- Family history
- High cholesterol
- High blood pressure
- High blood triglycerides
- Obesity
- Physical inactivity
- Smoking
Ischemic heart disease can lead to:
Chronic Angina
myocardial Infarction
congestive heart failure
arrhythmia
Thrombosis
Arteries can become narrower at some locations due to build-up of cholesterol rich deposits
Blood flow can become compromised due to obstructions (plaque) in the lumen of blood vessel
Plaque build up leads to…
Reduced diameter = increased resistance = reduced blood flow in vessel = increases velocity = reduces pressure at the location of the plaque
Can lead to angina/heart attack if occurs in blood vessels leading to heart
Atherosclerosis
is the hardening and thickening of the walls of the arteries
Thrombus
a cellular mass formed within the blood vessel. Composed of platelets, red blood cells, neutrophils and lymphocytes, held together by fibrin derived from the coagulation pathway
Major precipitating event in arterial thrombosis…
Platelet activation at the sites of atherosclerotic plaques
Plaque rupture leads to…
acute thrombosis → acute artery occlusion → tissue death → organ failure → death
Atherosclerotic plaques form due to…
build-up of lipids
If an atherosclerotic plaque ruptures…
thrombus forms which blocks the circulation of blood
Atherosclerosis is a…
progressive disease
Thrombosis =
formation of a blood clot
Thrombosis can lead to…
sudden block of coronary blood supply = heart attack
Over several years a plaque can grow…
obstructs artery which may mean that exercise may result in chest pain = stable angina
The plaque can spontaneously rupture…
the blood system tries to cover up the rupture by sending platelets and coagulation factors → thrombus forms…
the thrombus can cause occlusion of the remaining lumen.
If this occlusion is partial = episode of chest pain (can lead to small heart attack).
Full block = full heart attack.
Myocardial ischaemia…
Lack of blood flow to the heart muscle
no supply of metabolites
loss of oxygen
ATP depletion
loss of calcium homeostasis
calcium concentration becomes high inside cardiac cells
muscle cell cross-bridges remain bound so relaxation cannot occur = they contract to a point where the membrane ruptures and cell death occurs
Overtime this leads to…Cell death
Eventually… Tissue death = area of “infarction”
This leads to… Heart failure
After ischeamia…
Cells can recover with reperfusion depending on how long ischemia took place for
Most common cause of myocardial ischeamia…
the block of the coronary artery (artery that supplied blood to the heart tissue).