Cardiovascular Dysfunction Flashcards
Definition - cardiovascular disease
NICE, 2014
British Heart Foundation, 2015
No universally agreed definition…
Cardiovascular disease (CVD) describes disease of the heart and blood vessels caused by the process of atherosclerosis. It is the leading cause of death in England and Wales accounting for almost one third of deaths (NICE, 2014)
Cardiovascular disease (CVD) includes all the diseases of the heart and circulation including coronary heart disease, angina, heart attack, congenital heart disease, heart failure and stroke. (British Heart Foundation, 2015)
What disordered are included in CVD?
CVD tends to incorporate hypertension, ischaemic heart disease, angina pectoris, myocardial infarction, stroke, rheumatic
heart disease, congenital cardiac defects and
heart failure
Most of the diseases grouped under the
heading CVD are inter-related (e.g. stroke and hypertension = same process)
What causes heart failure?
- CVD is the primary aetiology of heart failure, although a variety of other factors also cause heart failure
(e.g. Heart valve defects caused by diseases such as
rheumatic fever or infection, primary disease of the
heart muscle known as cardiomyopathy, and
congenital heart disease)
- Much CVD is caused by atheromatous plaque build up
on the intima or inner layer of the arterial wall
Risk factors for CVD?
- Age
- Sex (More M)
- Family history of CVD
- Ethnic background
- Smoking
- Raised Blood Pressure
- Raised Cholesterol
- Low income/social deprivation (north/south divide)
Air pollution
Cholesterol…
What is
Total cholesterol
‘Good’ cholesterol
‘Bad’ cholesterol
Triglycerides
total cholesterol – the overall amount of cholesterol in
your blood, including both “good” and “bad”
cholesterol
good cholesterol (called HDL) – this makes you less
likely to have heart problems or a stroke
bad cholesterol (called LDL and non-HDL) – this
contributes to atherosclerosis and makes you more
likely to have heart problems or a stroke
triglycerides – a fatty substance similar to bad
cholesterol and considered the building blocks of
cholesterol
High levels of triglycerides and low levels of HDL raise
your risk for heart disease
Normal values for:
Total cholesterol
‘Good’ cholesterol
‘Bad’ cholesterol
Triglycerides
Normal
Total cholesterol - 5 or below
‘Good’ cholesterol - 1 or above
‘Bad’ cholesterol- 4 or below
Triglycerides - 2.3 or below
Lifestyle factors ?
Stress Personality - 'type a' Smoking Sedentary lifestyle CVD - brain and heart
Genetic link
- Genetics can influence the risk for heart disease. A
family history of cardiovascular disease (CVD) modifies
future risk of CVD depending on the number and age of
affected first-degree relatives
-Many cardiac disorders can be inherited, including
arrhythmias, congenital heart disease, cardiomyopathy,
and high blood cholesterol
- CHD leading to heart attack, stroke, and heart failure
can run in families - The gene variant ADAMTS7 is linked to a build up of plaque in the coronary arteries and is one of a number of genes associated with heart disease risk identified within the last few years
- Variants on chromosomes 9, 6 and 2, as examples, are also associated with heart
disease
Foetal Origins Hypothesis
David Barker
The Barker hypothesis states that adverse influences early in development, and particularly during intrauterine life, can
result in permanent changes in physiology and metabolism, which result in increased disease in adulthood
- This hypothesis originally evolved from observations by Barker and colleagues that the regions in England that had the highest rates of infant mortality in the early twentieth century also had the highest rates of mortality from coronary heart disease decades later
- The fetal origins hypothesis states that fetal under-nutrition in middle to late gestation, which leads to disproportionate fetal growth, programmes later coronary heart disease
Like other living creatures in early life,
human beings are “plastic” and able to
adapt to their environment.
The development of the sweat glands in first 3 years of life provides a simple example of this
Plasticity allows a ‘weather forecast’ - if mother is poorly nourished, baby expects environment to be harsh. This leads to reduced size and altered metabolism.
Disparities between predicted environment and actual environment then results in disease
e.g. diabetes, hypertension
Rapid weight gain in early childhood is associated with CVD
Links between cardiovascular factors & babies?
A substantial number of published studies suggest
that impaired fetal growth is related to higher risk of
hypertension, diabetes and CVD.
- Recent studies point to a particularly high risk of
cardiovascular disease in overweight or obese subjects with a history of impaired fetal growth and in subjects who experienced accelerated growth in childhood - Neonatal abdominal circumference has also been
shown to predict plasma cholesterol and fibrinogen
levels in men in later life-CVD linked - Babies born small in relation to the size of their
placenta have an increased risk of developing
hypertension - On the other hand babies who were reported to have
small placentas in relation to their birth weight are
more at risk of developing type 2 diabetes, sometimes
in combination with hypertension - Babies born small tend to have higher basal plasma
cortisol levels
Links with birth weight
Babies born small in relation to the size of their placenta have an increased risk of developing:
- Hypertension
- Coronary heart disease
- Non-insulin dependent diabetes
- Stroke
- Dislipidaemia
- Elevated clotting factors
- Impaired neuro-development
less well replicated inc.
depression
schizophrenia
lung disease
High birth weight -
polycystic ovary disease
Heart oxygen journey?
deoxygenated blood enters the Right Atrium, travels into the right ventricle, travels into the lungs via the pulmonary artery, oxygenation happens, then via pulmonary VEIN (oxygenated) into Left Atrium,then into left ventricle, via aorta into body, deoxygenated back to RA via vena cava
What illnesses are meant by: Acute Coronary Syndrome?
Includes The term 'acute coronary syndromes' encompasses a range of conditions including unstable angina, non-ST-segment-elevation myocardial infarction (NSTEMI) and ST-segment-elevation myocardial infarction (STEMI).
Whats the differene between Non-ST elevation MI and Unstable Angina?
Non-ST elevation MI is an unstable coronary syndrome which is differentiated from unstable angina by a subsequent rise in cardiac
enzymes.
NICE (2011) clinical guideline 94 – Unstable angina and NSTEMI
What is the disease process of ACS?
- This process is generally initiated by the
fissuring of an atheromatous plaque in the
coronary artery. - The extent to which the fissuring reduces
the blood flow to the myocardium determines the nature of the clinical events.
What is artherosclerosis?
From Atheroma which is Greek for porridge
Atherosclerosis is caused by the build up of fatty
deposits in the lumen of the artery.
As the fatty deposits build up they cause plaques or
atheroma to develop.
These plaques cause a narrowing of the artery lumen.
This narrowing means that there is reduced blood flow to the myocardium.
Theories of artherosclerosis?
‘Response to injury’ theory - repetitive injury to the inner lining of the artery
- “Thrombolitic Theory” - arterosclerotic process
What are schistocytes?
Fragments of RBC, broken off due to atheroma
Atheroma formation - describe the process.
Damage to Tunica Intima LDL enter (cholesterol) Oxidation of LDL Macrophages engulf Foam Cells Fatty Streak Fat moves into the intima = Bulge Hard white plaque Ulcerates – platelet aggregation – thrombosis
Pathogenesis of ACS - describe…
Haemorrhage into the plaque or atheroma causing internal
swelling and restriction of the lumen.
Smooth muscle contraction within the artery wall causing further
restriction of the lumen.
Platelet aggregation & formation of a thrombus on the surface of
the plaque causing partial or complete obstruction of the artery.
Reduces blood flow through arteries (Ischaemia, peripheral
vascular disease, angina)
Predisposition to thrombosis - MI
Weakening of vessel walls - aneurism
How many patients are aware that they have CVD prior to heart attack?
For 50% of patients their first
indication that they have
cardiovascular disease is the day they have their heart attack
Angina Pectoris
- Stable angina is NOT an Acute Coronary Syndrome.
The pain is usually experienced on exertion is
predictable, and is relieved with rest. - Controlled, preventative therapy, on movement or after
meals, partial occlusion, relieved with GTN. - Glyceryl trinitrate (GTN) is a spray used to relieve
angina (chest pain). When sprayed under. the tongue, it
relaxes and widens blood vessels in the heart and in the rest of the body improving oxygen delivery
Chest pain could be angina if:
Chest pain could be angina if: Feels tight, dull or heavy although some people (especially women) may have sharp, stabbing pain Spreads to the arm, neck, jaw or back Is triggered by physical exertion or stress Stops within a few minutes of resting Angina can also cause breathlessness Nausea Pain similar to indigestion Tiredness Some people have these symptoms without pain Presents when 70-75% of artery is occluded
How is unstable angina defined?
Unstable angina is defined by one or more of the
following:
1. Angina of effort occurring over a few days with
increased frequency provoked by less exertion
(crescendo angina).
2. Angina that occurs unpredictably and recurrently
without specific provocation. Usually short lived
may settle spontaneous or temporarily relieved by
GTN. But will reoccur within a few hours.
3. An unprovoked and prolonged episode of chest pain raising suspicion of an acute myocardial infarction but without definitive ECG or blood result changes.
4. When myocardial ischaemia is present, but without evidence of actual myocardial necrosis (normal serum troponin level), the clinical syndrome is described as
Unstable Angina.
Myocardial Infarction - define?
Occurs when a coronary artery becomes blocked or
significantly narrowed.
This is due to spasm or atheroma
Indicates a defined area of myocardial necrosis caused
by local ischaemia.
Myocardial necrosis begins within approximately 20-30
mins of the time of coronary artery occlusion
Infarct reaches full size in 3-6 hrs
Location of the MI is determined by site of the
occlusion within the coronary circulation.
ST elevation OR non ST elevation
Assessment of chest pain in MI?
The chest can feel like its being pressed or squeezed by a heavy object Pain can radiate across the chest, jaw, back or arms Accompanied by shortness of breath Weak/light headed Overwhelming anxiety Only relieved with opiates
Chest Pain P = Precipitating factors Q = Quality R = Region/Radiation S = Symptoms associated with pain T = Timing
How can you identify MI?
Chest Pain - crushing? heavy? breathlessness?
ECG Changes - ST elevation?
Blood test changes - troponin elevated?
Non-ST Elevation Myocardial Infarction vs.
Unstable Angina?
No troponin with angina
Thombus vs. Embolus
both are blood clots
Embolus is a travelling clot
Thrombus is a stationary slot
What is troponin?
regulatory protein, released with damage to the myocardial cells (as this is where troponin resides)
