PATHOLOGY- Heart disorders 1 Flashcards
Name the 4 chambers of the heart
Right ventricle
Right atrium
Left ventricle
Left atrium
What does the right hand side of the heart do?
Pumps deoxygenated blood to the lungs
What does the left hand side of the heart do?
Pumps oxygenated blood to the rest of the body
What does diastole mean?
Refers to the filing of the ventricles with blood (relaxation phase)
What does systole mean?
Refers to the contraction phase of the ventricles where good is ejected from the ventricles
Name the different valves of the heart
- Tricuspid valve
- Pulmonary valve
- Mitral valve
- Aortic Valve
Wha does the tricuspid valve separate?
It separated the right atrium from the right ventricle
What does the mitral valve separate ?
The left atrium from the left ventricle
What does the pulmonary valve separate?
The right ventricle from the pulmonary artery
What does the aortic valve separate
The aorta from the left ventricle
Talk though the path blood takes starting from the vena cava
1 Vena cava into the right atrium 2. Cuspid valve 3 Right ventricle 4. Pulmonary valve into the pulmonary artery 5. Lungs 6. Re-enters via the pulmonary vein into the left atrium 7. Mitral valve 8. Left ventricle 9. Aortic valve 10. Aorta to rest of the body
What is the general rule regarding blood found in the arteries (and which artery is the exception)
Arteries take OXYGENATED blood AWAY from the heart
apart from the pulmonary artery that carries DEOXYGENATED blood AWAY from the heart
What is the general rule regarding blood found in the vein (and which vein is the exception)
Veins take DEOXYGENATED blood to VISIT the heart
apart from the pulmonary VEIN that carries OXYGENATED blood to VISIT the heart
Name the 3 main vessels that supply OXYGENATED blood to the heart
- Left anterior descending artery
- The circumflex artery
- The right coronary artery
Where is the left anterior descending artery found?
Passes down the front of the heart
Where is the circumflex artery found?
Passes to the left hand side of the heart
Where is the right coronary artery found?
Passes to the right hand side of the heart
Which artery supplies the back of the heart (in most people)?
The right coronary artery
What are the circumflex artery and left descending coronary artery branches of?
The left main coronary artery
What is another name for the left main coronary artery?
The left main stem
What is the significance of the left main corner artery?
It is a small branch of the aorta that splits into the
- Left anterior descending artery
- The circumflex artery
What is ischaemic heart disease?
It describes a GROUP of clinical syndromes that relates to myocardial ischaemia
Define ischaemia
Cell injury resulting from localised HYPOXIA induced by reduced blood flow, most commonly due to a mechanical arterial obstruction
What s another name for ischaemic heart disease?
Coronary heart disease
What causes ischaemic heart disease in the majority of cases?
Coronary artery atherosclerosis causes this in 90% of cases
Give some clinical manifestations of ischaemic heart disease
- Myocardial infarction
- Angina (stable or unstable)
- Chronic ichaemic heart disease and heart failure
- Sudden cardiac death
Name the leading cause of death in the uk and worldwide
ischaemic heart disease
How any deaths in the UK are accused by ischaemic heart disease?
64,000 per year
180 per day
1 every 8 mins
Death rates for ischaemic heart disease have fallen over the years why?
- Awareness of modifiable life style factors
- Awareness of medical risk factors
- Better diagnosis and treatment
Give some treatment options we now have to manage ischaemic hear disease
- Drugs like statins
- Angioplasty
- Stenting
- Implantable defibrillators
- Ventricular asst devices
Give some common risk factors fo ischaemic heart disease
- Smoking
- Obesity
- Hypertension
- Diabetes
- Old Age
- Family history
- Dyslipidaemia
Who are more likley to get ischaemic heart disease men or women?
Men are at a grater risk than women
What is dyslipidaemia?
Abnormal lipid levels usually increased LDL levels relative to HDL
How can we treat dyslipidaemia?
Statins
What is the pathogenesis of ischaemic heart disease?
Imbalance between supply of oxygen and demand
Talk through the brief stages that occur in the heart that can lead to myocardial infarction
- Insufficient coranary perfusion
- Cardiac hypoxia
- Cell injury
If sustained - Myocardial cell death
- Myocardial infarction
How can we identify which coronary artery is blocked
By checking on an ECG to see which area of the heart is damaged
Which of the three coronary arteries is blocked in the majority of cases?
The left anterior descending artery is blocked in 50% of cases
This is also known as the artery of sudden death
On a cellular level what damage leads to ischaemic heart disease
Mitochondria death which leads to reduced ATP production
This leads to several problems
If the mitochondria becomes damaged what problems can that cause
- Sodium pump damage causing ER ad cellular swelling and los of microvilli
- Increased aerobic glycolysis increasing lactic acid levels causing clumping of nuclear chromatin
- Detachment of ribosomes which decreases protein synthesis
What is atherosclerosis?
Material build up in the walls of arteries
Does atherosclerosis affect arteries more or veins
Arteries
Name three key things that can lead to the build up of plaque in vessels
- Build up of lipids
- smoking
- high blood pressure
Talk through how atherosclerosis can happen
- Lipids build up in the walls
- Macrophages try and get rid of the lipids
- Macrophages die
- Leads to an inflammatory response
- Leads to the build up of fat and smooth muscle and fibrotic material in the blood vessel
The initial build up of lipids vessel is called what?
A fatty streak
What forms after the initial fatty streak and how?
Smooth muscle and lipid build up lead to the formation of:
FIBROFATTY PLAQUE
What three things can happen if plaque accumulation in the vessels get too much?
- Aneurysm and rupture
- Occlusion by thrombosis
- Critical stenosis
What is critical stenosis?
When so much plaque has occluded the arteries (>70%) that it has significantly affected blood flow
What happen to arteries if occlusion by thrombus occurs
What can it lead to
The plaque can suddenly rupture and burst leading to the formation of a blood clot over the rupture plaque
sudden occlusion occurs
can cause unstable angina or myocardial infarction
The severe symptoms of unstable angina and acute myocardial infarction area termed as…?
Acute coronary syndrome (ACS)
What causes unstable angina and myocardial infarction
Unstable plaque rupture
What causes stable angina?
Significant and progressive occlusion of vessel
What are acute coronary syndromes?
More severe symptoms of unstable angina
What is the difference between unstable angina and myocardial infarction?
There is no detectable myocardial cell damage in unstable angina
What are the clinical features of ischaemic heart disease
- Angina pectoris
- Pale and clammy
- Sweating
- Nausea
- Weak pulse or low BP
- Breathlessness
What is angina pectoris
“strangled chest”
What causes pain in angina pectoris?
Pain is due to inflammatory mediator release
Where is angina pectoris felt?
What is it preipitated by
Retrosternal chest pain that radiates to epigastrium, back, neck, jaw or shoulders
exertion, eating, exposure to cold or emotional stress
What is stable angina?
Angina pectoris that occurs for 1-5 minutes and is relieved by rest or GTN or other drug
What is unstable angina?
Angina pectoris that is more intense, lasts longer, can occur spontaneous at rest and can be prcicipiated by less exertion
Can progressively get worse
what are the clinical symptoms of ischaemic heart disease
chest pain
pale and clammy
sweating
nausea and vomiting
weak pulse/low blood pressure
breathlessness
How do we diagnose ischaemic heart disease
- Look at clinical features of pain
- Can look at changes on an electrocardiogram
- Look for cardiac blood markers
How do cardiac blood markers work?
When myocardial cells die they release a protein into the blood that is specific to those cells
If you take a blood sample and see the specific proteins (eg troponin) then you know cardiac cells are dying
what do you see with a sudden coronary artery thrombosis and why
nothing because theres no time for the tissues to react
what do patients who have a previous history of angina usually carry
GTN spray or tablets
If you fear patient is having an unstable angina attack or myocardial infarction what should you do?
- Call 999
- Reassure patient and put them in a comfortable position
- Give oxygen
- Give sublingual GTN if patient has it
- DO NOT give an inter muscular injection
- Aspirin 300mg and give note to hospital
- CPR if they collapse
What do the NICE guidelines say regarding patients with nonsystematic ischaemic heart disease?
- Vulnerable for 4 weeks following MI so check with medical practitioner before treatment
- Low dose aspirin should not be stopped or altered before dental treatment
- Antibiotic prophylaxis not recommended following surgery
BASIC RULE: don’t stop treatment if minor procedure with low risk fo bleeding and I you are unsure consult a cardiologist
Name some complications that can arise after suffering from a myocardial infarction
- Stroke (embolism)
- Cardiogenic shock (inability of the heart to sufficiently profuse the body as a result of sudden cardiac injury)
- Congestive heart failure (chronic impaired contractility)
- Cardiac tamponade (accumulation of blood in the pericardial sac)
- Arrhythmias (abnormal heart rhythms)
- Pericarditis (inflammation in the pericaridum (sac around heart))
Name the 4 main ways the heart can be effected after a myocardial infarction
- Impaired contractility
- Tissue necrosis
- Electrical instability
- Pericardial inflammation
What can impaired contractility cause?
1, Can lead to ventricular thrombus leading to stroke
- Hypotension that can increase ischaemia and cause cardiogenic shock
- Congestive heart failure
What can tissue necrosis cause?
- Papillary muscle infarction leading to congestive heart failure
- Ventricular wall rupture that causes cardiac tamponade
What is cardiac tamponade
Accumulation of blood in the pericardial sack
What can electrical instability in the heart cause|
Arrhythmias
What are arrhythmias
Abnormal heart rhythm
What can pericardial inflammation cause
Pericarditis
What is pericarditis
Pericardium inflammation
What is an aneurysm
An abnormal dilation of the ventricle due to myocardial infarction
What is heart failure?
Inability of the heart to pump enough blood to meet metabolic demands of the body
When can heart failure occur?
It is usually the end stage of many forms of chronic heart disease
- Work overload e.g. valvular heart disease / hypertension
- Myocardial damage (IHD) - acute severe IHD can cause severe HF
Give symptoms of heart failure
- Fatigue
- Breathlessness
- Peripheral oedema/ swelling
What are the 3 responses of the heart to heart failure?
Initially the heart will compensate to try and maintain function. It does this by either:
- Increasing contractility
- Cardiac hypertrophy
- Neurohumoural reposens
What is cardiac hypertrophy?
The heart increasing in size to try and maintain function and cardiac output after heat failure
Give some neurohumoural responses of the body in response to heart failure
Fluid is retained after low cardiac output is sensed
This ultimately leads to fluid overload
What is the ejection fraction?
It is the proportion of blood within the ventricle that is actually pumped out
What is the ejection fraction in a healthy individual?
55-70%
Name 2 different causes of heart failure
- Systolic dysfunction
- Diastolic dysfunction
What happens to ejection fraction in systolic dysfunction?
Decreased contractility which leads an ejection fraction of <40%
What can cause systolic dysfunction
- Ischaemic heart disease
- Valve disease
What can cause diastolic dysfunction?
Heart is too stiff and cannot fill properly
Wha effect does systolic dysfunction have on the ejection fraction?
Reduces the ejection fraction
Wha effect does diastolic dysfunction have on the ejection fraction?
Ejection fraction is preserved
Wha can cause diastolic dysfunction?
Hypertrophy
What happens if the left side of the heart fails?
Impaired output causing
- congestion in the pulmonary circulation
- Stasis of blood in the left side
- Inadequate perfusion of organs
If the left side of a patents heart is damaged what signs of symptoms may you see
- Breathlessness
- Oedema due to organ failure (systemic hypoperfusion)
What happens if the right side of the heart fails?
Increased “back pressure” through the pulmonary and venous circuit
If the right side of a patents heart is damaged what signs of symptoms may you see
Leg swelling and organ congestion
Is right handed failure of left side failure more common?
Neither is more common they both usually occur in combination (known as congestive heart failure)
Name some diseases that affect the valves
- Valvular stenosis
- Valvular regurgitation/ incompetence
- Infective endocarditis
What happens in valvular stenosis
They can fail to open leading to impaired forward flow of blood (stenosis)
What happen in valvular regurgitation/ incompetence
Valves fail to close fully leading to the backflow of blood
What happens in Infective endocarditis
The valves can get infected with vegetations which can lead to embolism and impaired mobility of the valves
What are the 3 likely outcomes abnormal valve function
- Abnormal blood flow
- Clot formation
- Risk of infection (endocarditis)
What is valvular stenosis almost always due to?
Chronic injury/ rheumatic fever
Name the 2 types of stenosis
- Mitral stenosis
- Aortic stenosis
what is aortic stenosis
what does it result in
narrowing of the aortic valve resulting in impaired blood flow through the aortic valve
what can acute valve disease lead to
what can chronic valve disease lead to
sudden death
heart failure
Give some pathological causes of mitral stenosis
Rheumatic valvular disease
Give some pathological causes of aortic stenosis
Calcific degeneration (caused by general wear and tear)
or
Rheumatic valvular disease
What is valvular incompetence/insufficiency usually due to?
Disease of the cusps or supporting structures
There are may causes and they can be acute or chronic
Name the 2 types of valvular incompetence
- Mitral incompetence
- Aortic incompetence
What can damage to the atrio ventricular valves cause?
Atrial fibrillation (unusual electrical signal in the atrium)
Name the valvular disease the is most common
Aortic stenosis
How can you treat aortic stenosis?
Valve replacement
Balloon dilation
what does aortic stenosis do to the left ventricle
causes hypertrhophy of left ventricle
what can put you at risk of aortic stenosis
bicuspid valve- congenital
what can aortic stenosis cause
- Left ventricle hypertrophy -> ischaemia or loss of function
- syncope (passing out suddenly)
- eventually leading to decompensated CHF
what is the distinctive feature that patients with aortic stensosis have
ejection systolic murmur (abnormal heart sound when the heart contracts )
What 3 things cause mitral regurgitation/incompetence
- calcification of valve ring (annulus)
- ischaemic heart disease causing fibrous scarring of papillary muscle and tethering valve leaflets
- papillary muscle rupture
- infective endocarditis
- mitral valve proplapse
what is mitral valve proplapse
Congenital condition myxomatous degeneration of mitral valve leaflets
what is the distinctive feature that patients with mitral incompetence have
pan systolic murmur
how would you treat mitral incompetence
valve replacement
what 6 things can aortic regurgitation/insufficiency be caused by
- dilation of thr ascending aorta, often secondary to hypertension and/or aging
- infective endocarditis
- syphilis
- ankylosing spondylitis
- rheumtoid arthiritis
- marfan syndrome
what is vrtually the only cause of mitral stenosis
rheumatic fever/heart disease
what effect does mitral stenosis have
- Obstruction to left atrium
- Pulmonary congestion
- Right ventricular hypertrophy
- Right sided heart failure
