Cardiovascular disease Flashcards
What is cardiovascular disease?
Umbrella term
CHD is an important component
Biggest cause of death in the UK
What has happened to the rates of CVD in the last years?
They have risen
Due to changes in the lifestyle of humans
What is an important molecular aspect of CHD?
Atherosclerosis
Chronic inflammatory condition characterised by the development of plaques on the artery walls
What are the plaques formed in atherosclerosis?
Patchy deposits of fatty material
Is atherosclerosis fatal?
No
But the rupture of the atherosclerotic plaque often leads to thrombosis, which can cause life-threatening complications
4 stages of atherosclerosis development
Endothelial dysfunction - healthy arteries undergo injury, increasing the permeability of the walls
Fatty streak - immune cells and low-density lipids are recruited. Monocytes mature into macrophages which ingest cholesterol to form foam cells
Plaque progression - smooth muscle cells migrate into intimal layer and form fibrous cap over the plaque by releasing collagen
Plaque rupture - when the contents of the plaque are exposed to blood, coagulation forms a thrombus
What are the two types of risk factors of atherosclerosis?
Modifiable
Non-modifiable
Examples of modifiable risk factors
Dyslipidemia
Hypertension
Smoking
Diabetes Mellitus
Obesity
Examples of non-modifiable risk factors
Age
Male gender
Hereditary
How do risk factors increase the development of atherosclerosis?
Cause damage to the endothelial cells lining the artery
Trigger an immune response that leads to migration of leukocytes, lipids and other materials into the artery wall
Describe cardiac ageing
Over time the heart shows dysfunction to the heart muscle wall and stiff aorta
This is due to hypertrophy and fibrosis
Leads to reduced ejection fractions
What is an important factor underlying cardiac ageing?
Angiotensin 2 release
Changes in ECM of ageing heart
Increase collagen concentration
Decreased elastin concentration
What is seen in vascular ageing?
More ROS, inflammation and angiotensin II
Decreased bioavailability of the precursor of NO
How is iNOS pathogenic in vascular ageing?
Instead of producing NO, it produces superoxides which damage the vessel
What is the superoxide produced by iNOS?
Peroxynitrite
Destroys plasma membranes, decreases NO availability, decreases vasodilation and causes endothelial dysfunction
How is angiotensin dysfunctional in vascular ageing?
Increases production of MMPs
Decreases NO
Increases vessel thickness
TRUE or FALSE
Men are always more likely to develop CVD
FALSE
Men are more likely to develop CVD up to a certain age
Women are protected due to oestrogen, which activates second messengers leading to mitochondrial biogenesis and increased fatty acid utilisation
How does increased mitochondrial bioavailability protect against CVD?
Protects from ROS through production of antioxidant defences
Compare the mitochondrial function of men and women
Females = high ATP, less ROS, little calcium, cell survival is more efficient
Males = mitochondria are more prone to damage, cell survival is less efficient
TRUE or FALSE
After menopause, women are equally as likely to develop CVD as men
FALSE
Women have higher CVD risks after menopause
How is ethnicity linked to CVD?
CHD, Type II DM and stroke rates are higher in South Asians
High BP and Type II DM rates are higher in African Caribbeans
Which system is faulty in arterial hypertension?
Renin angiotensin system
Arterial stiffness and ventricular changes activate this system
How does the renin angiotensin system increase chances of CVD?
Remodelling arterial walls
Calcification
Elastic fibre degradation
Effects of hypertension
Increased afterload
Increased stroke volume
Increased myocardial oxygen demand
Arterial damage
Heart failure
What is one of the most important risk factors of CVD?
Smoking
How does smoking increase CVD rates?
Tobacco has a high number of substances that activate endothelial cell dysfunction
This facilitates the development of atherosclerosis
How is cholesterol linked to CVD?
The higher the cholesterol, the higher the risk
What are the two types of cholesterol important in CVD?
LDL = deposits cholesterol in blood vessels
HDL = removes cholesterol from blood vessels to the liver
What is important regarding cholesterol and CVD?
The correct balance between HDL and LDL levels
How is obesity related to CVD?
Not a direct risk factor
Increases the incidence of underlying mechanisms relating to CVD
How is diabetes related to CVD?
Increases inflammation
How much does diabetes increase the chances of developing CVD?
Diabetic individuals are 3 times more likely to develop CVD compared to normal
Two important therapies that help prevent CVD
Fibre
Exercise - most important
How does fibre decrease the chances of developing CVD?
Helps lower the cholesterol content in the blood
Forms a gel which binds some cholesterol in the small intestines
Takes it out of the body
Beneficial effects of exercise
Reverses endothelial dysfunction
Anti-atherogenic effects
Anti-inflammatory effects
