Heart disorders I Flashcards
Describe the structure of the heart and the cardiac cycle
Deoxygenated blood from systemic to right atrium which passed to right ventricle which primary which primary function is to pump oxygenated blood into the pulmonary circulation to allow oxygenation to occur in the lungs
Oxygenated blood from the lungs passes into the left atrium into the left ventricle and out through the aortic valve into the aorta , the aortic arch and into the systemic circulation to oxygenate the organs in the systemic circulation
Diastoles is a term refers to the filling of the ventricles with blood
Relaxation phase of ventricular - systole
Refers to the contraction phase of the ventricles where the blood is ejected from the ventricles either into the pulmonary circulation or into the systemic circulation
Describe the valves and circulation of the normal heart
Tricuspid valve separates the right atrium from the right ventricle
Blood then from right ventricle is ejected through the pulmonary valve into the pulmonary artery
Left atrium is separated from left ventricle by the mitral valve
Oxygenated blood is ejected through the aortic arch through the aortic valve
Deoxygenated blood comes from the systemic circulation into the right atrium int the right ventricle and into the pulmonary circulation where its oxygenated goes into the left atrium through the mitral valve out thought the arctic valve into the systemic circulation again to allow oxygenated blood to pass into the capillaries of the end tissues
Describe the coronary vasuclatrue of the normal heart
3 main vessels that supply oxygenated blood to the heart
left main coronary artery passes to the font of the heart
circumflex coronary artery passes to the left hand side of the heart and passes posteriorly in some individuals and
the right coronary artery passes to the right hand side of the heart
For most people, the blood supply from the back of the heart comes from the right coronary artery
what is ischaemic heart disease
Ischemia = cell injury resulting from hypoxia induced by reduced blood flow most commonly due to mechanical material obstruction
describe the epidemiology of ischamic heart disease
what are the risk factors of Ischaemic heart disease
What is the pathogenesis of Ischaemic heart disease
Main coronary vessels
Give rise to damage and ultimately death to different parts of the heart
Being able to detect changes in electrical activity over the surface of the heart gives us an indication of which part of the heart is damaged
Basics of ECGS
Look at pattern of change of electrical activity over the heart, we can look at which part of the heart or determine which part of the heart is damaged
at a cellular level , myocardial damage results from ischemia , mechanical obstruction of blood flow into the tissues
Blood clot which is blocking the flow of blood into the heart
Affects the respiratory function at a cellular level and impaired mitochondrial function and has sorts of adverse effects on cells
So the cellular pumps start to fail, normal aerobic respiration and protein synthesis starts to fail
In short term , the cells start to swell up
When hypoxia staines, the cells will break apart
Important in diagnosis because when ,lymphocytes start to break , they release very specific proteins into bloodstream which can be detected to allow diagnosis of ischemic heart disease
What is atherosclerosis
Mechanical obstruction to blood flow into heart
Lipid can build up in intima of vessel
Smoking or blood pressure can damage blood vessel
Leads to accumulation of material in arteriole vessel all
Build up of lipid in the vessel wall and as the lipid accumulates, the lipid is absorbed by macrophages
The macrophages die and over time an inflammatory response builds up or is elicited in the vessel wall in the intima and eventually there is a build up of smooth muscle as well
Process of by which you get lipid buildup and the lesion is called a fatty streak and then eventually you get smooth muscle accumulation and fibrosis and this is called fibrolipid plaque
The development or accumulation of fat smooth muscle as a result of endothelial dysfunction is atherosclerosis
Atherosclerosis is a buildup of fatty material,smooth muscle and fibrotic material within the intima of a blood vessel
What happens int eh process of atherosclerosis
Lipid build up occurs in artery
Fatty streak
Accelerated endothelial damage
Smooth muscle proliferation
Fibrofatty plaque
Individuals due of something else
Critical stenosis- plaque grown so large it that is significantly occluding blood flow into the part of the heart that’s supplied with the vessel
Critical stenosis occurs when the plaque occludes over 75% of the vessel luminal diameter
Autopsy - when we see someone that has died , there’s no other obvious causes of death and we see coronary arteries that are over 75% occluded, then its reasonable on the balance of probabilities to conclude that they have likely died of ischaemic heart disease
Critical stenosis can cause impairment of blood flow and people can become symptomatic, IE develop chest pain if for example the heart is put under unusual amounts of strain so for example under exercise
Under resting conditions, the blood can just about meet the demands of the myocardium but when the individual exercises , then the blood flow is impaired
Plaque can instead of becoming progressively narrow, can suddenly rupture
The top of the plaque cna burst open and this exposes the inner contents of the plaque to the blood
Results in a sudden blood clot forming it over the ruptured plaque and you get a sudden occlusion of the vessel by a thrombus
The resultant coronary artery thrombosis causes much more dramatic and sudden symptoms such as unstable angina, or myocardial infarction
Normal artery that over a period of time is exposed to increased amounts of lipids in the blood
The lipid accumulates in the vessel wall
Eventually there is a inflammatory reaction to the lipid accumulation and there’s fibrosis and smooth muscle proliferation
If this progresses over a certain period of time and becomes critical then you have a fixed lesion or a critically stenotic lesion which when the individual exercise , they have a clinical presentation of something called stable angina
This plaque cna rupture as we’ve discussed, if the rupture does cause complete conclusion then the individual has a symptom that’s described as unstable angina or if it completely occludes and causes death of the myocardium, then this results in myocardial infarction.
These presentations of unstable angina and acute MI, when the plaque ruptures, they give much more dramatic symptoms and this presentation of these sets of symptoms are known as acute coronary syndromes
Acute coronary syndromes are sudden and severe clinical manifestations of ischemic heart disease
Unstable angina and MI are caused by unstable plaque rupture
More severe symptoms and are termed acute coronary syndromes
The difference is that there is no detectable myocardial cell damage in UA
what are the clinical features of angina pectoris
describe stable angina
Describe unstable angina
Describe other clinical features of angina
How would you diagnose Ischamic heart disease
Cardiac cells - normal electrical activity of heart - determine damage to heart
Protein helps in cardiac muscle cells, the proteins released into the bloodstream
Troponin is important in diagnosing MI
Describe NICE guidelines for stable angina
What are the complications of MI
Contractility can be impaired
If heart globally impaired, heart will not work properly
Inability of heart to sufficiently perfuse the body as a result of sudden cardiac injury is called cardiogenic shock
Tissue necrosis - rupture mitral valve - lead to congestive heart failure
Cardiac tamponade is accumulation of blood in the pericardial sac
When heart is damaged through myocardial infarction , you can also get abnormal electrical activity in the heart
Sudden aberrant electrical activity going through the heart
Result in arrhythmias
Abnormal heart rhythms and this can cause rhythms such as ventricular fibrillation which and cause symptoms and even death
If the surface of the heart that is irritated or is inflamed due to cell death of the ventricular surface, then you can get inflammation in the pericardium
Sac around the heart - called pericarditis
Arrhythmias can cause sudden death in chronic IHD
Abnormal regulation causes patients to collapse and die
Define heart failure and its symptoms
what is the pathogenesis of heart failure
Cardiac hypertrophy - heart is working harder to ambient CO
Neurohumoral responses
renin angiotensin- kidney detect CO is not efficient
Reacts by retaining fluid
Valvular damage
Heart has to react and compensate damage
Larger and thicker
Remodelling and adapting
Abnormal protein development
Heart is enlarged and fibrotic
Dysfunction of heart failure
what is ejection fraction
what is systolic dysfunction
what is Diastolic dysfunction
Describe 3 different types of heart failure
Congestive heart failure - both and left and right = breathlessness, pulmonary edema and peripheral oedema
How do valves go bad
Valves can either fail to close fully
Abnormal valve function - risk of clot formation , endocarditis
Describe acquired valve disease
Describe Aortic stenosis
What is Mitral regurgitation
What is Aortic regurgitation
What is Mitral stenosis
