HistoPath of Cardiovascular Disease Flashcards
What percentage of deaths are caused by heart & circulatory disease?
- 26% of all deaths
- 1/4 die from it
Roughly how many people in the UK have heart disease?
- 7 million people alive have heart disease
Describe Athersclerosis
= build up of fatty plaques within artery walls, constricting blood flow
- caused by various factors - generally unhealthy lifestyle
- plaques build up over a lifetime
-depending on the location = different disease (called myocardial infarction)
What is a heart attack?
- heart attack occurs when 1 of the coronary arteries is blocked - 2 effects;
1. Lack of oxygen may cause electrical instability
2. longer term oxygen deprivation will cause necrosis of a region of heart muscle
What does electrical instability result in?
- chaotic heartbeat (known as ventricular fibrillation)
- this can then cause the heart to stop beating (cardiac arrest) which is lethal if resuscitation is not performed
Describe Heart Failure
- heart becomes less efficient, at pumping blood around the body
- characterised by shortness of breath & sometimes swelling in extremities when circulation is poor
- can lead to fibrillation & cardiac arrest
What does the heart do to compensate in heart failure?
it develops extra muscles in the ventricles
Describe Aneurysm
- aneurysm = weakening of the wall of an artery
- causes artery to form a balloon-like protrusion
- if the aneurysm bursts this can be life-threatening
- commonly affects the aorta, but also in the brain
Describe Congenital Heart Disease
- caused by an error during process of embryonic development
- most common = affecting almost 1% of children
Describe Cyanotic Congenital Heart Disease
- 25% of cases
- heart defects that reduce the amount of oxygen delivered to the body
- leading to blue appearance & shortness of breath
- requires urgent treatment
Describe Acyanotic Congenital heart disease
- 75% of cases
- Heart defects where the blood contains enough oxygen, but it’s pumped throughout the body abnormally
- generally less severe but may have long-term health effects
- patient may have no symptoms & appear healthy
What are examples of acyanotic congenital heart disease?
- ventricular septal defect = 20-25% of CHD
- atrial septal defect = 8-13% of CHD
Atrioventricular septal defect = 4-5% of CHD
Describe Ventricular Septal Defect
= hole in heart linking 2 ventricles
Describe Left to Right Shunt
- common in acyanotic CHD
- blood pressure is higher in left than right ventricle
- so a hold in a ventricular wall lead to L->R flow
- oxygenated blood is still pumped through aorta so effect is relatively minor
Describe Atrial Septal Defect
- ASD is similar to VSD but affects the upper part of the heart
- leads to mixing of oxygenated & deoxygenated blood
- L->R shunt
Describe Patent Ductus Arteriosus
- in the womb, lungs aren’t functioning & foetus receives oxygen from mother
- a bypass exists which allows blood from right side to skip the lungs & enter the aorta
- so both sides of the heart are working to pump the blood around the body of the foetus
- this bypass= Ductus Arteriosus
- vessel usually closes at birth when baby takes its first breath
- in some CHD conditions it remains open meaning the heart has to work harder
Describe Coarctation of the Aorta
- some conditions result from narrowing of an artery
- both coarctation & stenosis meaning narrowing & may affect either the aorta or pulmonary artery
- in this case the aorta is narrowed near the arch of the aorta
What are an example of cyanotic heart disease?
Conotruncal (outflow tract) defects ;
- Tetralogy of Fallot
- Transposition of the great arteries
- Double-outlet right ventricle
- Truncus arteriosus
Describe Tetralogy of Fallot
- Cyanotic CHD
- can be found individually & will cause a cyanotic disease but when found together they will produce a more serious cyanotic condition;
1. Ventricular septal defect
2. pulmonary stenosis
3. overriding aorta
4. right ventricle hypertrophy
Describe Right to Left Shunt
- cyanotic CHD
- Tetralogy patient has a hole in ventricular septum but it is a R->L shunt this is due to other lesions which reverse blood flow;
1. Pulmonary artery is narrowed so not much blood can enter
2. aorta entrance is shifted to right to lie over VSD (overriding aorta) makes it easier for doexygenated blood to get into aorta
Describe the Transposition of Great Arteries
- cyanotic CHD
- arteries are switched around (transposed) so that the aorta is connceted to right ventricle & pulmonary artery to left ventricle
- means deoxygenated blood is pumped around body
- condition is only viable if there is a connection between systemic & pulmonary circulations allowing lixing of blood
Describe a Double Outlet Right Ventricle
- cyanotic CHD
- both arteries are connected to right ventricle
- meaning deoxygenated blood is pumped around the body
- condition is only viable if there is a connection between systemic & pulmonary circulation allowing mixing of blood
Describe how the heart is derived from the mesoderm
- shortly after implantation the human embryo undergo a process called gastrulation
- results in formation of 3 germ layers
- cardiovascular system is derived from the mesoderm
Describe an embryonic heart
- heart is the first organ to form in the body
-first heart structure takes the shape of a linear tube, very different to the mature anatomy
