28 - Cardiovascular Disease 1 Flashcards Preview

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Flashcards in 28 - Cardiovascular Disease 1 Deck (54):
1

Ischaemic heart disease - definition

Inadequate blood supply to the myocardium via atheroma/ thrombus/ myocardial hypertropy

2

Ischaemic heart disease - pathogenesis

Acute & chronic
Autoregulation of coronary blood flow breaks down if

3

Ischaemic heart disease - syndromes

Angina pectoris
Acute coronary syndrome
Sudden cardiac death
Chronic ischaemic heart disease

4

Angina pectoris - types

Typical/stable - fixed obstructable, predictable on exertion
Variant/Prinzmetal - coronary artery spasm, unpredictable
Crescendo/unstable - red flag syndrome due to plaque disruption

5

Acute coronary syndrome

Acute MI (+/- ECG ST elevation)
Crescendo/unstable angina

6

Acute ischaemia - causes and why

Atheroma + acute thrombosis / haemorrhage
Lipid rich plaques at most risk

7

Acute ischaemia - what is it?

Regional transmural myocardial infarction

8

Acute ischaemia - management

Thrombolysis

9

Acute ischaemia - Diagnosis

Clinical
ECG
Blood cardiac proteins

10

Subendocardial myocardial infarction - why is that region vulnerable?

subendocardial most vulnerable due to less blood going to it as capillaries run over endocardium

Can infarct without any acute coronary occlusion

11

Subendocardial myocardial infarction - ST elevation?

Rarely

12

Blood markers of cardiac myocyte damage - troponins T&I

Detectable 2-3hrs peaks at 12h detectable at 7 days.

Raised post-MI but also in PE, heart failure & myocarditis

13

Blood markers of cardiac myocyte damage - Creatine kinase

Detectable 2-3hrs, peaks at 10-24hrs, detectable to 3 days

14

Blood markers of cardiac myocyte damage - Myoglobin

peak at 2hrs but also released from damaged skeletal muscle

15

Blood markers of cardiac myocyte damage - lactate dehydrogenase isoenzyme 1

Peaks at 3 days, detectable to 14 days

16

Blood markers of cardiac myocyte damage - aspartate transaminase

Also present in liver so less useful as a marker of myocardial damage

17

Blood markers of cardiac myocyte damage - most useful/only one used?

Troponin

18

Blood markers of cardiac myocyte damage - creatine kinase subtypes

CK MM - muscle
CK BB - brain, lung
CK MB - cardiac, possibly muscle

19

Familial hypercholesterolaemia - commonest mutations

Low density lipoprotein receptor gene (1in500)
Apolipoprotein B (1 in 1000)

Note homozygous more severe

20

Whats a xanthoma and egs.

Tendons
Periocular
Corneal arcus
Early atherosclerosis

21

Which is more common - primary hypertension or secondary?

Primary (95%)
Main secondary is hyperthyroidism

22

Renin cycle

Synthesised, stored and release in juxtaglomerular apparatus in the wall of afferent renal arterioles.

Cleaves Angiotensinogen to Ang I
Ang I is converted to active Ang II in many tissues

23

Ang II facts

potent natural vasoconstrictor
V. short half life
Stimulates adrenal cortex to produce aldosterone

24

Aldosterone facts

Physiological mineralocorticoid
Renal action causes sodium and water retention
Circulating blood volume increases

25

Conn's syndrome - causes and why

Caused by excess aldosterone secretion

Why: adrenocortical adenoma, micronodular hyperplasia, renal sodium&water hypertension, elevated aldosterone w/ low renin, potassium loss (via muscle weakness.

26

Conn's syndrome - diagnosis

Diagnose by CT scan of adrenals in presence of metabolic abnormalities

27

Phaeochromocytoma - what is it? what causes the symptoms?

Tumour of adrenal medulla
Presents due to secretion of vasoconstrictive catecholamines - AD and NA

28

Phaeochromocytoma - clinical presentation

Pallor
Headaches
Sweating
Nervousness
Hypertension

29

Phaeochromocytoma - diagnosis

24hr urine collection for AD metabolites

30

Cushing's disease - what is it? + effects

Overproduction of cortisol by adrenal cortex

Potentiating SNS and has mineralocorticoid (aldosterone-like) action of kidneys causing hypertension

31

Cushing's disease - causes

Adrenocortical neoplasm usually an adenoma

A pituitary adenoma (80% cause) or paraneoplastic effect of other neoplasms (small lung cell carcinomas).

The other neoplasms produce adrenocorticotrophic hormone that stimulates the zona fasciculata cells of the adrenal cortex to produce cortisol

32

Hypertension - effects

CV - hypertensive heart disease
Renal failure
Cerebrovascular incident

33

Hypertension - hypertensive heart disease

Systemic hypertension leads to increased LV blood pressure -> LV hypertrophy
When pressure is too great LV fails to pump blood at normal rate and dilates

34

Hypertension - renal effects

Vascular changes:
Arterial intimal fibroelastosis
Hyaline arteriolosclerosis

Slow deterioration in renal function leading to failure

35

Hypertensive cerebrovascular disease

Hypertensive encephalopathy
Increased risk of rupture of abnormal arteries - atheromatous (intracerebral haemorrhage); berry aneurysm of the circle of Willis (subarachnoid haemorrhage)

36

Hypertension - hypertensive crisis

BP >180/120

37

Hypertension - hypertensive crisis clinical presentation

Acute hypertensive encephalopathy
Renal failure
Retinal haemorrhages

Urgent treatment

38

Hypertension - acute hypertensive encephalopathy

Clincopathological syndrome
Diffuse cerebral dysfunction - confusion, vomiting, convulsions, coma and death
Rapid intervention required to reduce accompanying raised intracranial pressure

39

Pulmonary hypertension - caused by

Loss of pulm. vasculature
2* to LV failure
Systemic to pulm. art. shunting
Primary or idiopathic

40

Pulmonary hypertension - causes

Increased RV work to pump blood
RV myocardium hypertrophy initially w/o dilation
Later dilation and systemic venous congestion as RV failure develops

41

What is Framingham risk score?

Calculates an individual's risk of CVD based on multiple risk factors and algorithms

42

Other risk assessment systems

SCORE
QRISK2
Joint British societies risk prediction charts

43

What is renin? Where is it made and released from?

Synthesised, stored in and released from juxtaglomerular apparatus in wall of afferent arteriole of kidney

44

What does renin do?

Cleaves angiotensinogen to angiotensin I

45

Where is Ang1 cleaved?

AngII in many tissues

46

What is AngII and what does it do?

Potent vasoconstrictor
Very short half-life
Stimulates adrenal cortex to produce aldosterone

47

What is aldosterone?

Physiological mineralocorticoid

Causes sodium, and in turn, water retention

Increases blood volume

48

What is Conn's syndrome?

Excess aldosterone secretion

Adrenocortical adenoma

Renal sodium and Na retention

Elevated aldosterone and low renin

Potassium loss

49

What does potassium loss cause?

Muscular weakness
Cardiac arrhythmias
Parasthaesesia
Metabolic alkalosis

50

Phaeochromocytoma - what is it?

Tumour of adrenal medulla
Secretion of vasoconstrictive catecholamines - AD & NA

51

Phaeochromocytoma clinical presentation

Pallor
Headaches
Sweating
Nervousness
Hypertension

52

Phaeochromocytoma diagnosis

24hr urine collection of AD metabolites

53

Cushing's disease

Overproduction of cortisol by adrenal cortex

Caused by: pituitary adenoma (80%)

Adenocortical neoplasm - usually adenoma

Paraneoplastic effect of neoplasms

54

How would another neoplasm cause cushing's disease?

Produce adrenocorticotrophic hormone that stimulates zona fasciculata cells of the adrenal cortex to produce cortisol

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