Pathology Flashcards
what is atherosclerosis?
a disease where there is the formation of fatty deposits (lesions) within the large and medium sized arteries known as sclerotic plaques
an atherosclerotic plaque contains what components
connective tissues (collagen) produced by smooth muscle cells providing structural strength, inflammatory cells- macrophages, lipid deposits known as fatty streaks, and foam cells- taken up lipoproteins via specialised membrane bound scavenger receptors
what are the most common sites of atherosclerosis?
points of arterial branching and bifurcation, where the lumen of the vessel is narrower- increases pressure on the endothelium hence there is a more likely chance of damage.
name 5 risk factors of atherosclerosis
obestiy, asian prevalence, smoker, inactivity and hypertensive
What are the treatments/interventions for atherosclerosis?
plasminogen inhibitors and alpha-2 antiplasmin- inhibits plasminogen being converted into plasmin.
what is high blood pressure?
a blood pressure where the treatment to reduce it will reduce the risk of complications arising. It is beneficial to treat
describe primary hyperaldosteronism (conns syndrome)
it is a benign adenoma in the adrenal gland (one or both) which results in excessive production and release of aldosterone.
Characterised by: Hypertension (increases sodium retention in the kidneys) Hypokalaemia- increases potassium loss and Alkalosis.
what is produced excessively in Cushings syndrome, and what does this result in?
cortisol, it acts in a similar way to aldosterone- increases BP but also increases glucose levels
What is fibromuscular dysplasia of the artery wall?
this is increased muscle cells in the artery wall- increased thickness
what are the treatments for hypertension?
ACE inhibitors, beta blockers, calcium channel blockers, diuretics
why are caucasians over the age of 55 and afro carribbeans given calcium channel blockers and diuretics to treat hypertension instead of ACE inhibitors?
As you get older you responsiveness to renin decreases, afro caribbeans are also less sensitive to renin and thus the ACE inhibitors have a lesser antihypertensive effect
What is heart failure?
the inability to expel blood out of the heart
what is cor pulmonale
a term used to describe right sided heart failure secondary to lung disease
give 5 reasons why blood supply to the heart may be impaired
- atherosclerosis of the arteries
- thrombosis within a blood vessel
- thromboembolic blocking a blood vessel supplying the heart
- arteritis
- reduced blood pressure
what is hypovolaemia?
shock resulting from a significantly decreased blood volume
What is polysythemia?
high production and thus levels of RBC’s in the blood plasma. It is usually a compensatory mechanism as a result of hyperaemia
Name 5 differential diagnosis for symptoms which suggest ischaemic heart disease
- Pericarditis
- pulmonary embolism
- chest infection
- dissection of the aorta
- gastro-oesophageal reflux
What is angina?
a mismatch of oxygen demand and supply in the heart because of a narrowed coronary artery which causes discomfort in the chest and adjacent areas
What is Prinzmetal’s angina?
this is the mismatch of perfusion and demand of the heart due to arterial spasms- its a type of unstable angina
unstable angina
unexpected chest pain whilst resting, due to atherosclerosis of the coronary vessels supplying the heart.
What is a myocardial infarction?
this is a term applied to necrosis of the heart after an acute interruption of the coronary blood supply
Describe the 3 types of infarction and the locations within the heart muscle where a myocardial infarction may occur.
Subendocardial infarction- death of the innermost layer of the myocardial tissue
Patchy infarction- throughout the myocardial tissue layers
Transmural infarction- tissue death the full thickness of the myocardial tissue from the epicardium to the endocardium
Describe 3 main features of a myocardial infarction
- severe angina
- raised ST segment on and ECG
- breathlessness
what anti-thrombotic therapy is given to reduce the risk of immediate vascular occlusion following a MI?
Dual anti-platelet therapy- GP2b/3a given IV, anticoagulant fondaparinux (inhibits fibrin and thrombin formation)
When are fibrinolytic drugs offered to a patient with a recent MI? and name one
Offered to patients who cannot have a percutaneous coronary laparoscopy within 90 minutes of hospital admission. Streptokinase.
What is valvular incompetence?
the loss of a normal functioning valve- it fails to prevent regurgitation of blood after contraction of an individual chamber
What is a vegetation on the heart?
an infective thrombotic nodule developing on the valves of the heart that impairs normal functions- motility and closure
what is calcific aortic stenosis?
the narrowing of the aortic valve due to calcific deposits in the cusps, progressively distorting the valve shape and ability to close properly
what are the 3 main symptoms of aortic stenosis?
- chest pain
- dizziness
- occasional fainting
what is an Austin flint murmur?
this is a sound heard in aortic regurgitation because the regurgitating jet impinges on the anterior mitral valve lobe causing it to vibrate
what is myxomatous degeneration of the mitral valve and what can it lead to?
this is the dysfunction of the mitral valve because there is too much length of papillary muscle making the tension weak and allowing the valve to invert
Name 3 signs of mitral regurgitation
- Auscultation- a soft 1st heart murmur at the apex radiating to the axilla
- 3rd heart sound- due to left arterial overload
- displaced apex beat
Name 3 signs of mitral stenosis
- diastolic mumur- low pitched rumble at the apex
- loud S1 snap at the apex beat due to the initial rapid opening of the valve (the tips are often fused and so a force is required to open them)
- shorter time interval between S1 and S2
What is rheumatic fever?
this is a condition which develops after a streptococcal infection in the upper respiratory tract. Immune reactions to the pathogen produces antibodies which cross react with myocytes and valvular glycoproteins in the heart.
Giant cell myocarditis
a rare and often fatal cardiac disease with areas of muscle cell death due to macrophage giant cells.
name 5 predisposing factors to endocarditis
- rheumatic fever
- abnormal/prosthetic heart valve
- dental sepsis
- IVDU
- age- young and elderly
What is infective endocarditis and what bacterial pathogen commonly causes it?
infection of the endocardial layer of the heart (this lines the valves and innermost layer of the heart.) Staphylococcus Aureus
what is a roth spot? and what condition is it commonly found in?
it is a vegetation in the retina. commonly seen in infective endocaridits.
What criteria is used for the diagnosis of infective endocarditis?
Modified Dukes criteria
What is the most effective method of treating infective endocarditis?
4-6 weeks IV penicillin or gentamicin.