Download Atherosclerosis

Cardiovascular Diseases
Cardiovascular Diseases: is a general
term describing diseases of the heart and
blood vessels
• Cardio= heart
• vascular= blood vessels
Atherosclerosis
Atherosclerosis
• Atherosclerosis is hardening of the
arteries”
Artery
walls
become
progressively
thickened
due
to
accumulation
of
fatty
deposits,
smooth muscle cells, and fibrous
known as”plaque’’
Atherosclerosis
The presence of plaque narrowing the
lumen of an artery and in turn restricts
blood flow.
 It can affect any organ or tissue in the
body .Coronary arteries ,Brain ,Kidneys .
Development of Atherosclerosis
• Atherosclerosis begins to develop as early
as childhood or adolescence. Usually
progresses over several decades before
symptoms develop.
• it initially arises in response to minimal but
chronic injuries that damage the inner arterial
wall.
• Damage to the artery causes the immune
system to respond and attracts monocytes, T
cells and platelets.
• Monocytes attached to LDL and results in fatty
deposits along artery walls ( fatty streaks)
Atherosclerosis
• As the plaque thickens – accumulates
calcium and cholesterol within the
lipid core can crystallize and harden
• The lipid accumulation eventually
narrows the diameter of the arterial
lumen
Atherosclerosis
• Plaque progression may cause
narrowing or expansion of an
artery
• Arteries that expand are less
likely to interfere with blood blow
but more likely to have:
Rupture
Induce clotting
Increase risk of heart attack or
stroke
Causes of Atherosclerosis
• Reasons for atherosclerosis
development are complex.
• Factors that initiate atherosclerosis
either cause:
1. direct damage to the artery wall
2. allow lipid materials to penetrate its
surface.
Causes of Atherosclerosis
1. Inflammation and infection
 Plaque development is an inflammatory
response to an injury on the artery wall
so the body’s immune system is directly
involved in its development.
 Persistent infection within the body may
contribute to plaque formation
2- Shear stress
The stress of blood flow along the
artery walls is called shear stress.
 Shear stress can cause damage
within the arteries and cause
inflammatory response
 High blood pressure intensifies
the stress of blood flow on arterial
walls

Causes of Atherosclerosis
3. Cigarette smoking
 Chemicals in smoke (nicotine) are
toxic to endothelial cells, and the
resulting damage can initiate plaque
development
 Impairs normal functions of artery
cells and induces vasoconstriction
 Promotes blood clotting, raises LDL
and lowers HDL cholesterol levels
 Passive smoking can cause these
effects as well
Causes of Atherosclerosis
. Elevated (LDL) and (VLDL):
 Elevated (LDL) and (VLDL) can
promote atherosclerosis
especially if they are oxidized
from free radical
 Oxidized LDL and VLDL taken
up and retained in the artery
wall
Stimulate blood clotting
• Inhibit some of the normal protective
functions of high-density lipoproteins
(HDL)
• Low levels of HDL may contribute to
the development of atherosclerosis
because it prevent oxidation of LDL
and
remove
cholesterol
from
circulation
Causes of Atherosclerosis
5. Diabetes Mellitus (DM)
Chronic hyperglycemia leads to the
production of advanced glycation end
products(AGEs) which :
• Damage blood vessels
• Worsen atherosclerosis
Promotes blood clot formation that
contributes to plaque progression
Causes of Atherosclerosis
6 . Age and gender:
• Advancing age is strongly associated with
atherosclerosis due to accumulative
exposure to risk factors.
 Aging is significant risk factor for men at
age 45 or older and women at age 55 or
older
 Women’s risk increases as they
reach menopause is attributed to
loss of estrogen’s protective effect
on arterial function in women
 Levels of amino acid
homocysteine may damage
artery walls and promote blood
clotting, rise with age and are
generally higher in men
Coronary Heart Disease
CHD
Coronary Heart Disease
• Caused by :
1. atherosclerosis in the large and
medium-sized arteries
2. Coronary spasms or inflammatory
diseases that cause narrowing of the
coronary arteries
Symptoms of CHD
• Pain or discomfort in chest region
• Perceived as feeling of heaviness,
pressure or a squeezing sensation
• Pain radiating to left arm, shoulders,
back throat, jaws or teeth
• Pain is persistent for several minutes,
subsides with rest
CHD Risk Assessment
CHD is often linked with multiple risk
factors of the metabolic syndrome
• LDL (> 100 mg/dL) and total blood
cholesterol (> 200 mg/dL) levels
• High-density lipoprotein levels (HDL)
≤ 60 mg/dL
• Triglycerides, fasting >150 mg/dL
CHD Risk Assessment
• Body mass index (BMI) >24.9
• Abdominal obesity
Male > 40 inches
Female > 35 inches
• Blood pressure (systolic and/or diastolic
pressure) >120/>80
• Physical inactivity
• Smoking
• Presence of diabetes
Therapeutic Lifestyle
Changes for Lowering CHD
Risk
People who have CHD are often
advised to make dietary and lifestyle
chances.
An approach to risk reduction called
Therapeutic Lifestyle Changes
The main features include:
1. Cholesterol lowering diet
2. Weight reduction
3. Regular physical activitty
1- Polyunsaturated & Monounsaturated Fat
 Replace saturated fats with monounsaturated or
polyunsaturated fats
 Polyunsaturated fats promote slight reduction of
HDL & may contribute to oxidative stress or
increase inflammation within the body
 So limit the consumption of polyunsaturated to
10% kcalories
 Monounsaturated fat to 20% of kcalories
2-Dietary cholesterol
 high cholesterol intake can raise LDL
levels.
Therapeutic lifestyle changes (TLC)
recommendation is to reduce
cholesterol intake to < 200 mg/day
3-Trans fats
when Trans fatty acids replace saturated
fats in the diet as when margarine replaces
butter can :
 Raise LDL levels
 May cause decline in HDL levels
TLC recommendation – keep trans fat intake
as low as possible
Reduce consumption of doughnuts, potato
chips, crackers, fast foods and French fries.
4-Soluble fibers
 diet rich in soluble fibers can reduce LDL-c
by inhabiting cholesterol absorption in small
intestineReduce the absorption of
cholesterol and bile by binding them in the
intestinal tract
 Adding an extra 5 – 10 grams of soluble
fiber daily is associated with approximately
5% reduction in LDL cholesterol.
 Dietary sources include oats, barley,
legumes and fruits
5-Sodium/potassium intake:
some people are sensitive to sodium than
others
• Sodium may raise blood pressure whereas
potassium can has blood lower blood
pressure
 Low sodium diet that contain generous
amounts of fruits and vegetables, low fat
milk products , nuts and whole grains has
been found to substantially reduce blood
pressure
6-Fish and omega-3 fatty acids
may benefit people with heart
proplems by:
• Suppressing the inflammatory response
• Reducing blood-clotting time
• Stabilizing heart rhythm
• Lowering triglyceride levels
• Two servings of fish per week or 1
gram of EPA and DHA daily
7-Regular physical activity
Regular physical activity reverses a
number of risk factors for CHD
Lowers triglycerides, raises HDL, lowers
blood pressure, promotes weight loss,
improves insulin sensitivity, strengthens
heart muscle and increases coronary
artery size and tone.
At least 30 minutes of moderate-intensity
exercise most days of the week
7-Regular physical activity
60 minutes of physical activity is
recommended for weight loss
Vigorous activity increases risk of MI and
sudden death in individuals with
diagnosed heart disease – increase
activity gradually
8-Smoking
• Compounds in smoke :
Damages blood vessel cells
Decreases the oxygen-carrying
capacity of the blood (contributing to
ischemia)
Promotes vasoconstriction & blood
coagulation
Raises heart rate and blood pressure
quitting smoking improves CHD risk
quickly.
9-Weight reductions
May improve CHD risk factors such as
blood pressure, insulin resistance,
triglyceride levels and HDL levels
Initial weight-loss goal – no more
than 10% of original body weight
10-Vitamin supplementation &
CHD risk
• Homocysteine is known risk factor
for CHD . Increased intakes of
folate, B6 & B12 can lower
homocysteine levels.No
recommendation for antioxidant
vitamins – C & E
Lifestyle Changes for
Hypertriglyceridemia
• For mild hypertriglyceridemia
Controlling body weight
Becoming physically active
Quitting smoking
Avoiding a high carbohydrate intake
Restricting alcohol
Lifestyle Changes for
Hypertriglyceridemia
• For severe hypertriglyceridemia
Medications
Very-low-fat diet, < 15% kcal from fat
If fat restriction severe – MCT replace
fats and oils
Hypertension
Hypertension (Htn)
• An estimated 30% of people are unaware
that they have Htn.
• Elevated blood pressure forces the heart to
work harder to eject blood into the
arteries; this effort weakens heart muscle
and increases the risk of developing heart
arrhythmias, heart failure, and even
sudden death.
• Primary cause of stroke and renal failure
Hypertension
Contributing Factors for Hypertension
• Aging – increases with age
• Genetic – family trait
• Obesity – BMI > 25 . obesity raises blood
pressure, in part, by altering kidney
function and promoting fluid retention.
• Salt sensitivity – 30 – 50 % with Htn are
sensitive to salt and can improve blood
pressure by reducing salt consumption.
Hypertension
Contributing Factors for Hypertension
• Alcohol : heavy consumption (3 or
more drinks/day) is strongly associated
with hypertension. Alcohol’s specific
role in blood pressure is unclear.
• Diet – low in potassium, calcium and
magnesium have been shown to
reduce blood pressure
Hypertension
Treatment for Hypertension
• Lifestyle modifications – see next
table
• Weight reduction
• DASH eating plan
Provides fiber, K+, Mg, Ca
 Limits red meat, sweets, sugar-containing
beverages,
 ≤ 7% saturated fat, ≤ 150 mg
Cholesterol/day
 Na restriction : less than 2400 mg/ day
best if ≤ 1500 mg/day
medications