CVS Session 12 Flashcards Preview

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Flashcards in CVS Session 12 Deck (93):
1

What diseases are associated with arterial occlusion?

Peripheral artery disease
Coronary artery disease

2

What diseases are associated with venous congestion?

Varicose veins
DVT

3

What causes the pain experienced in intermittent claudication?

Build up of metabolites

4

Which veins in the leg are assisted by musculaneous pump?

Deep

5

When do varicose veins become symptomatic?

Perfusion is reduced leading to venous ulcer

6

Which veins of the leg are affected in varicose veins?

Superficial

7

Stasis of blood in which vessels presents with a tender, swollen calf in the affected limb?

Calf, popliteal, femoral or iliac veins

8

If a patient with DVT becomes breathless and experiences chest pain, what has most likely happened?

Pulmonary embolism

9

What is experienced with >70% occlusion of the coronary arteries?

Symptoms of ischaemic heart disease on exercise

10

When does blood flow through the LCA largely occur?

During diastole

11

What happens when there is >90% occlusionsion in a coronary artery?

Ischaemia at rest

12

What are the S/S of ischaemic heart disease?

Central chest pain that radiates to neck and left arm and is brought on by exercise, relieved by rest

13

What is defined as a positive exercise stress test?

Chest discomfort or ST depression seen on ECG

14

What is the primary action of nitrate treatment in ischaemic heart disease?

Venodilation to increase preload of the heart

15

What treatments are used to decrease the workload of the heart and act on vasculature to decrease afterload?

Calcium channel antagonists

16

What is the numerical definition of hypertension?

Arterial B.P. > 140/90

17

What complications can follow from prolonged hypertension?

LVH --> heart failure
Arterial disease of the coronary, cerebral, kidney and retinal arteries as well as the aorta

18

What lifestyle changes can be recommended to control hypertension?

Weight loss
Exercise
Decrease dietary salt intake

19

How does the radiation of chest pain in unstable angina compare to that in MI?

More limited

20

What is the role of troponin?

Regulate excitation-contraction coupling

21

Which patients tend to not feel chest pain in MI?

Diabetics

22

What causes MI patients to display pallor and sweating?

Strong sympathetic reaction

23

How does necrosis of the myocardial wall differ between NSTEMI and STEMI?

NSTEMI: not full wall
STEMI: full wall

24

What biomarkers can be used to detect MI?

CK-MB
Troponin T and I

25

How does the ECG waveform progress in STEMI?

ST elevation --> R decreases and pathological Q wave forms --> T wave inversion and Q wave deepens --> ST normal and T inverted --> ST and T normal, Q wave persists

26

How long after MI are R wave changes seen on an ECG?

Horus

27

When is T wave inversion seen on ECG following a STEMI?

Days 1-2

28

How is a pathological Q wave defined?

>1 mm width
>2 small squares depth

29

How long does it take for the ST to return to normal on an ECG following a STEMI?

Days

30

How long does it take for the T wave to return to normal on an ECG following STEMI?

Weeks

31

What is cardiac arrest?

Unresponsiveness associated w/lack of pulse

32

What are the two broad causes of cardiac arrest?

Asystole
Ventricular fibrillation

33

What is asystole?

Loss of electrical and mechanical activity in the heart

34

What is the most common cause of cardiac arrest?

Ventricular fibrillation

35

What three things can cause ventricular fibrillation and therefore lead to cardiac arrest?

MI
Electrolyte imbalance
Arrhythmias

36

Give two examples of arrythmias which may lead to cardiac arrest.

Long QT
Torsades de Pointes

37

What are the three treatments used in cardiac arrest?

Basic life support
Advanced life support
Adrenaline

38

What is basic life support?

Chest compression and external ventilation giving ~20% of cardiac output

39

How does defibrillation treat cardiac arrest?

Depolarises all cells and puts them into refractory period allowing for a coordinated restart

40

How does a pharmacological dose of adrenaline act when treating cardiac arrest?

Activates alpha-1 receptors to increase heart function and decrease TPR

41

What is generalised shock?

Acute condition of inadequate blood flow throughout the body

42

What leads to circulatory shock?

A catastrophic fall in arterial blood pressure due to decreased cardiac output or decreased TPR beyond the heart coping capacity

43

What equation describes mean arterial blood pressure?

CO x TPR (flow x resistance)

44

What equation describes cardiac output?

HR x SV

45

What causes the TPR to decrease to a level that the heart cannot cope with?

Extensive systemic vasodilation

46

Which three types of shock result from decreased cardiac output?

Mechanical (obstructive)
Cardiogenic
Hypovolaemic

47

Which types of shock arise from decreased TPR?

Toxic
Anaphylactic

48

What is cardiogenic shock?

Pump failure

49

What can cause cardiogenic shock?

Damage to L. ventricle following MI
Ventricular tachycardia
Severe bradycardia
Acute worsening of heart failure

50

How may central venous pressure be altered in cardiogenic shock?

May not be (sorry) or can be increased

51

What causes the large decrease in arterial pressure in cardiogenic shock?

The heart fills but cannot pump effectively

52

What exacerbates the problem of cardiogenic shock?

Poor perfusion of coronary arteries

53

What is the affect on the kidneys of cardiogenic shock?

Poor perfusion --> oliguria

54

Which two pathologies can cause mechanical shock?

Cardiac tamponade
Pulmonary embolism

55

How does cardiac tamponade cause mechanical shock?

Blood/fluid in pericardial space exerts pressure on heart and prevents proper relaxation and filling

56

What is limited in mechanical shock?

End diastolic volume

57

What happens to the central venous pressure in mechanical shock?

Increases

58

What happens to the arterial blood pressure in mechanical shock?

Decreases

59

Why is SV altered in mechanical shock?

Heart attempts to beat faster due to continued electrical activity so SV decreases

60

How does pulmonary embolism cause mechanical shock?

Massive PE --> occlusion of large pulmonary artery --> R ventricle cannot empty properly --> CVP increases --> decreased bloodflow to L heart

61

How does the left atrial pressure change in mechanical shock?

Decreases

62

How does the arterial blood pressure change in mechanical shock?

Decreases

63

What else may be seen in a patient with mechanical shock due to pulmonary embolism in addition to the S/S of shock?

S/S of PE: chest pain and dyspnoea

64

How does shock lead to multi-organ failure?

Decrease in arterial BP is sufficient enough to cause decrease in tissue perfusion

65

What is hypovolaemic shock?

When blood volume is reduced so that cardiac output cannot be maintained

66

What is the most common cause of hypovolaemic shock?

Haemorrhage

67

What can cause plasma loss which leads to hypovolaemic shock?

Severe burns
Diarrhoea
Vomiting
Looks of sodium ions

68

At what percentage of bloodloss does hypovolaemic shock become symptomatic?

20-30%

69

At what percentage of blood volume loss is the serious shock response seen?

30-40%

70

What does the severity of hypovolaemic shock depend on?

Amount and speed of bloodloss

71

How are baroreceptors activated in haemorrhage?

Decreased venous pressure --> decreased CO --> arterial B.P. drops

72

What effects does activation of the baroreceptors have in hypovolaemic shock?

Increased sympathetic stimulation: increased heart rate, increased contractility, peripheral vasoconstriction and venoconstriction

73

What is internal transfusion?

Body's mechanism of increasing blood volume in hypovolaemic shock

74

How does internal transfusion work?

Increased TPR reduces downstream capillary hydrostatic pressure so fluid moves in to capillaries

75

What are the S/S of hypovolaemic shock?

Tachycardia
Weak pulse
Pale skin
Cold, clammy extremities

76

What does decompensation lead to?

Multi-system failure

77

What is the progression of decompensation?

Hypoxic tissue damage --> vasodilators released, build up and overtake SNS --> increased TPR and decreased B.P. --> vital organs not perfumed

78

Which are the two types of nonvolaemic shock?

Toxic (septic)
Anaphylactic

79

What is nonvolaemic shock?

Normal blood volume but circulatory volume increases

80

How do endotoxins seen in septic shock cause nonvolaemic shock?

Overcome SNS to cause vasodilation --> severely decreased TPR --> arterial pressure drops --> vital organs unperfused

81

How can endotoxins from circulating bacteria cause hypovolaemic shock in septicaemia?

Cause capillaries to become leaky

82

What is the vasoconstriction response from activated baroreceptors overridden by in septic shock?

Vasodilation mediators

83

What is seen in the vasculature in the later stages of toxic shock?

Vasoconstriction

84

What are the S/S of toxic shock?

Tachycardia
Warm and red extremities
Strong pulse

85

Which type of shock is acutely life threatening?

Anaphylactic

86

What causes the large decrease in arterial pressure seen in anaphylactic shock?

In sever allergic reaction mast cells release powerful vasodilators such as histamine and other mediators which decrease TPR

87

How is cardiac output increased in anaphylactic shock?

Increased SNS

88

Why does the increase in cardiac output seen in anaphylactic shock not restore systemic perfusion?

It is not enough to match the systemic vasodilation

89

What do mediators released by mast cells cause in addition to vasoconstriction which makes the patient breathless and the situation acutely life threatening in anaphylactic shock?

Bronchoconstriction
Laryngeal oedema

90

What are the S/S of anaphylactic shock?

Difficulty breathing
Collapsed
Increased HR
Red, warm extremities

91

Why is adrenaline given to treat anaphylactic shock?

To activate more alpha-1 receptors than the body can with endogenous NA and adrenaline

92

What two problems with the vasculature can cause poor perfusion?

Venous congestion
Arterial occlusion

93

Which two types of shock are considered as distributive shock?

Sepsis
Anaphylaxis