Cardiovascular Disease 1 Flashcards
What is the definition of ischemic heart disease?
inadequate blood supply to the myocardium
What causes ischemic heart disease?
↓ coronary blood from (e.g. thrombus)
myocardial hypertrophy
imbalance in supply v demand
where is low diastolic flow most likely?
sub-endocardial - furthest way from a blood supply
how long does it take before ischemic heart disease damage is irreversible?
20-30 mins
at what % does autoregulation of coronary blood flow breaks down?
> 75%
at what % of stenosis may be insufficient at rest?
> 90%
What are the 4 Ischaemic heart disease syndromes?
angina pectoris
acute coronary syndrome
sudden cardiac death
chronic ischemic heart diesease
What are the 3 types of angina pectoris and which one is a ‘red flag’?
typical/stable: fixed obstructon, predictable symptoms depending on exertion
variant/prinzmental: coronary artery spasm
crescendo/unstable: often sue to plaque disruption. RED FLAG
What are the two types of acute coronary syndrome?
acute myocardial infarction (+/- ECG ST elevation)
crescendo/unstable angina
What are the two circumstances in which a sub-endocardial myocardium can occur without acute coronary occlusion?
stable atheromanous occlusion of the coronary circulation
acute hypotensive episode
What is a transmural MI?
ischemic necrosis of the full thickness of the affected muscle segment(s) - from the endocardium through the myocardium to the epicardium
What is the gross and microscopic appearance of an MI before 24 hours?
gross: normal/dark
microscopic: necrosis and neutrophils
What is the gross and microscopic appearance of an MI from 3-7 days?
gross: hyperaemic border, yellow centre
microscopic: macrophages
What is the gross and microscopic appearance of an MI from 3-6 weeks?
gross: scar
microscopic: collagen scar
What is the main blood marker for cardiac myocyte damage?
Troponins T & I - detectable from 2-3 hours but peaks at 12 hours, up to 7 days
raised post MI and also PE, heart failure & myocarditis
What are the 3 subtypes of the blood marker creatine kinase?
CK MM - muscle (cardiac and skeletal)
CK BB - brain, lung
CK MB - mainly cardiac, also skeletal muscle
What are the complications of MI’s?
contractile dysfunction chronic cardiac failure arrhythmias infarct extension myocarial rupture pericarditis - dresslers syndrome mural thrombosis ventricular aneurysms
What are the two most common genes mutated in familial hypercholesterolaemia?
low density lipoprotein receptor
apolipoprotein B
Is hetro or homozygous familial hypercholesterolaemia treatment less complex and more affective?
heterozygotes
develop xanthomas
early primary treatment with statins
What is a normal BP?
120/80mmHg
abnormal around 140/90 and above
Name some systems involved with causing primary hypertension
Cardiac baroreceptors
Renin-angiotensin- aldosterone system: angiotensin II = vasocontrictor, aldesterone = water retension
Kinin-kallikrekin system Naturetic peptides Adrenergic receptor system Autocrine factors produced by blood vessels Autonomic nervous system
what are the effects of hypertension?
Hypertensive heart disease
Renal failure
Cerebrovascular accident
what is the process of hypertensive heart disease?
Systemic hypertension → ↑ left ventricular blood pressure
Left ventricle hypertrophy in response to ↑ work needed to pump blood
When the pressure is too great = dilatation
What is a ‘hypertensive crisis’?
BP >180/120mmHg
signs and symptoms of organ damage e.g. renal failure
urgent treatment required
What is the Framingham risk score?
Calculates an individual’s risk of cardiovascular disease based on assessment of multiple risk factors
What us Conn’s syndrome?
excess aldosterone secretion usually due to adenocortical adenoma low renin low K+ diagnosed by CT of adrenal glands
What is phaeochromocytoma?
tumour of the adrenal medulla
due to secretions of vascoconstrictive catecholamines e.g. adrenaline
symptoms: headache, pallor, Sweating, Nervousness, Hypertension
Diagnosis: 24hr urine collection for adrenaline metabolites
What is cushing’s disease?
Overproduction of cortisol by adrenal cortex
Caused by: adrenocortical neoplasm, pituitary adenoma, paraneoplastic effect e.g. effect of small cell lung carcinoma
