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Flashcards in Cardiovascular Deck (156):
1

In what form does Hb carries about 15% of its respiratory carbon dioxide?

carbaminohaemoglobin

 

1

What percentage of respiratory carbon dioxide does Hb carry as carbaminohaemoglobin?

15%

1

Name three factors that can shift the O2 saturation curve to the right

Increased DPG Increased temperature Decreased pH

1

What effect does altitude adaptation have on the O2 saturation curve?

 

Shifts it to the right

 

1

What is a typical EDV?

110 to 120ml (Guyton and Hall, 1996)

1

 

What is a typical cardiac output?

 

 

5-5.25 L/min

 

1

What effects does parasympathetic stimulation of the heart have?

 

Decreased heart rate

 

1

What is APTT

Activated partial thrombin time

1

Identify these valve events

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1

What are the 3 layers of a blood vessel?

Intima

Media

Adventitia

1

Which vessels contribute most to blood pressure?

Arterioles

1

Define embolus

Intravascular mass carried in the blood stream to a remote site.  May be solid, liquid or gaseous

1

Define atherosclerosis

Accumulation of lipid and fibrous connective tissue (plaque) in the intima of medium and large arteries

1

Name 4 ways endothelium is implicated in atherosclerosis

  1. Endothelial damage increases permeability to LDL
  2. Damaged endothelium loses its normal anti-coagulant properties
  3. Endothelium recruits macrophages through expression of selectins, ICAM and VCAM
  4. Endothelial cells don't produce as much prostacyclin or NO → impaired vasodilation

1

What is the ligamentum arteriosum a remnant of?

Ductous arteriosus

1

What condition is this?

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Aortic regurgitation

2

What does concentric hypertrophy compensate for?

Increased afterload

3

What is the order of the cardio exam?

General inspection. Palmar creases. Capillary refill. Radial pulse. BP. Conjunctiva. Lips and tongue. JVP. Carotid pulse. Palpate apex beat. Auscultation. Lungs. Shin oedema. Dorsal pedis pulse. Posterior tibial pulse.

3

Define eccentric hypertrophy

Normal  relative wall thickness

Increased LV mass

LV enlargement

4

Define concentric hypertrophy

Increased relative wall thickness

Increased LV mass

No LV enlargement

5

Define compliance

ability of any chamber to accept increased volume

6

What are the constitutive subunits of Hb in adults and foetuses?

Adults: 2 alpha and 2 beta Foetuses: 2 alpha and 2 gamma

6

What type of blood vessels are these?

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Arterioles

7

What condition is this?

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Mitral stenosis

8

What effects does sympathetic stimulation of the heart have?

Increased heart rate and force of contraction

8

What 2 forms may a true aneurysm take?

Sacular (unilateral outpouching) and fusiform (bilateral outpouching)

8

What is the molecular target of heparin?

Heparin enhances activity of antithrombin III, which inhibits factor Xa and thrombin 

9

What percentage of red blood cell dry content does Hb make up?

97%

11

Name 4 outcomes of atherosclerosis that predispose to CV disease

• Stenosis
• Impaired vasodilation
• Unstable plaque
• Local prothrombotic environment

12

What makes up about 97% of red blood cell dry content?

Hb

14

What does eccentric hypertrophy compensate for?

Increased volume (preload)

15

What are the 4 main classes of drug used to treat hypertension?

ACE inhibitors

Angiotensin receptor antagonists

Beta blockers

Calciium channel blockers

16

What is a typical ejection fraction?

60% (Guyton and Hall, 1996)

16

List 5 acute signs of hypovolaemia

Tachycardia 

Hypotension

Cold/clammy skin

Poor capillary refill (> 2 secs)

Tachypnea (if severe hypovolaemia)

16

What are 4 distinguishing features of the phrenic nerve course?

  1. Runs along scalenus anterior muscle
  2. Passes between subclavian artery and vein
  3. Passes anterior to lung root
  4. Pierce diaphragm

17

Why does Hb carry nitric oxide bound to a globin thiol group? And when does Hb release it?

It rrelaxes vascular walls and enhance gas diffusion. Hb releases NO at the same time as oxygen.

17

What type of blood vessel is this?

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Arteriole

19

How is bradykinin degraded?

By angiotension converting enzyme

20

Define thrombus

Clotted mass of blood that forms within the cardiovascular system during life

21

Define afterload

Load encountered by ventricle at the beginning of systole.

The amount of work the heart needs to do to eject blood 

22

What effect does beta adrenoceptor stimulation have on the heart?

Increased heart rate and cardiac contractility

23

What is it called when there is an infection of heart valves?

Endocarditis

24

What effect does shifting the O2 saturation curve to the right have on Hb affinity for O2?

Decrease

24

Where does the parasympathetic nervous system innervate the heart?

SA node and AV node

25

What is the function of lipoproteins?

 liporoteins transport fats such as cholesterol in the blood

27

When CO increases, what happens to venous pressure?

Decreases

28

Name two mechanisms Hb uses to achieve variable sigmoid binding character for oxygen association

Subunit cooperativity and allosteric effectors

29

What are 4 important things to ask about when taking a syncope history?

Before. What were you doing before it happened? Did you noticing anything else just before it happened?

During. How long were you unconscious for? Did anyone see it happen...what did they say?

After. How long did it take you to recover? How did you feel afterwards?

PMHx previous episodes? Heart problems?

31

What is the main risk factor for aortic disection?

Hypertension

32

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32

What is the characteristic histological feature of elastic arteries?

Up to 50 layers of elastin in the media

33

How do beta blockers treat arrythymias? 

Reduce sympathetic drive to SA node

36

What are the braches off the arch of the aorta from right to left?

Brachiocephalic a (branches into right subclavian a and right common carotid a)

Left common carotid a

Left subclavian a

37

What type of blood vessel is this?

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Medium vein

38

What cardiac phase does S2 correspond to?

Isovolumetric relaxation

40

At the level of which thoracic vertebrae does the heart sit?

T5 to T8

42

 

The names of angiotensin receptor antagonists end with what?

 

 

-sartan

 

43

Define compliance

Ability of a chamber to accept a volume of fluid

43

Mitral regurgitaiton would typically cause which type of hypertrophy?

Eccentric hypertrophy

45

Where is the sternal angle?

Horizontal line between manubriosternal joint and T4/T5

46

Describe 5 steps in secondary haemostasis

1 vessel damage releases tissue factor 2 extrinsic pathway: parathrombin → thrombin, 3 fibrinogen to fibrin, 4 fibrin crosslinks under factor XIIIa control 5 meshwork

46

What are the contraindications to treatment with ACE inhibitors?

Bilateral renal stenosis

Pregnancy

Angioneurotic oedema

47

What does the vascular funciton curve describe?

Describes what happens to venous pressure when CO varies

48

What is cardiac remodeling?

Increase of relative wall thickness without increase in left ventricle mass

49

What are the 3 components of Virchow's triad of thrombosis?

Vessel wall Blood composition Blood flow

50

What is the descending order of WBC concentrations in the blood?

NLMEB

51

What are the 3  critical intermediates of cholesterol synthesis?

 HMG-CoA (hdroxymethyglutaryl-CoA),

isoprene 

squalene

54

What do the names of ACE inhibitors end in?

-pril

55

What is a typical SV?

70ml (Guyton and Hall, 1996)

56

What is the molecular target of warfarin?

Vitamin K reductase

Inhibition of this prevents reduced VitK acting as a cofactor for activation of factors 2, 7, 9 and 10

57

What are the 3 main components of the coagulation system?

Vasoconstriction, platelet plug and fibrin mesh

58

What type of noradrinergic receptors are found on the heart?

Beta 1 (because you have 1 heart)

58

Name 3 vasoactive agents that endothelium releases and describe their effect on vasculature
 

 

Vasoconstrictor: endothelin
Vasodilator: NO and prostacyclin (PGI2)

 

58

How do K+ channel blockers affect arrhythmias?

Prolong cardiac AP by slowing repolarisation

59

What percentage of the blood is in the arteries?

13%

62

List 5 factors that may affect the effects of warfarin

Diet (VitK)

Hepatic disease

Hypermetabolic state

Pregnancy

Drug interactions, eg NSAIDs, EtOH

63

What are the 3 general complications of atherosclerosis?

Infarct

Ischaemia

Aneurysm

65

Volume overload would typically cause which type of LV hypertrophy?

Eccentric

67

During which cardiac phase is ventricular volume greatest?

Isovolumetirc contraction

68

Define preload

The amount of stretch on cardiac myocyte fibres at the end of diastole.

 

69

Name 3 substances that have cholesterol as a precursor in their synthesis

Bile acids

VitD

Steroid hormones

70

The names of beta blockers end in what?

-olol

71

Define diaphoresis

Profuse sweating

72

Where are cholinergic receptors on the heart found?

SA node and AV node

73

What is the upper limit for recommended cholesterol levels?

 5.5 mmol/L

74

A new drug called dozatapril is on the market. What class of drug is this likely to be?

ACE inhibitor

75

Aortic stenosis would typically cause what kind of LV hypertrophy?

Concentric

76

Where does ligamentum arteriosum attach?

Bifurcation of pulmonary trunk to inferior aspect of aortic arch

77

What is the most common cause of LV hypertrophy?

Myocardial infarction

79

What is the mechanism of action of statins? 

All statins are competitive inhibitors of HMG-CoA reductase

80

What effect do Na+ channel blockers have on the cardiac action potential?

Reduce phase 0 (up phase) slope and peak of ventricular AP as well as shorten repolarisation

82

What is the average heart mass of a healthy young adult? 

159g

83

Name three factors that can shift the O2 saturation curve to the left

Decreased DPG Decreased temperature Increased pH

84

How do Ca2+ channel blockers improve arrhythmias? 

Reduce heart rate and conduction through SA and AV node

85

Name 7 modifiable risk factors for atherosclerosis

- Hypertension
- Smoking
- Diabetes mellitus
- Obesity
- High LDL:HDL ratio
- Physical inactivity
- Proteinuria

86

What are the 'big 5' risk factors for atherosclerosis?

Hypertension

Diabetes

Hypercholesterolaemia 

Smoking

Family history

87

How is ejection fraction calculated?

EF = (SV/EDV) * 100

88

Where does the sympathetic nervous system innervate the heart?

SA node, AV node and ventricles

89

 

Which factors does warfarin inhibit?

 

 

2, 7, 9, 10

 

90

Which 3 things will affect SV?

Preload

Cardiac contractility

Afterload

91

Describe 4 steps in primary haemostasis

1 Vessel damage exposes von Willibrand factor on basement membrane and collagen 2 vWF binds to Gp1b on platelets 3 Platelet: adhere, flatten, recruit, degranulate (ADP and thromboxin A2) 4 platelet plug

92

Hypertension would typically cause which type of LV hypertrophy?

Concentric

94

Which ventricle is less compliant?

Left (because has thicker wall)

95

What percentage of the blood is in the heart?

7%

96

What percentage of the blood is in the capillaries?

5%

97

During which cardiac phase is ventricular volume least?

Isovolumetric relaxation

99

A new drug called buprolol is on the market. What class of drug is this likely to be?

Beta blocker

100

How is hypertension Dx?

Chronic BP greater than 140/90 mmHg

101

Branches of the descending aorta supply which 4 structures?

Intercostal aas

Pericardium

Esophagus

Bronchial aas

102

What cardiac phase does S1 correspond to?

Isovolumetirc contraction

103

What are the 4 major classes of drugs used for arrhythmias?

Beta blockers

Calcium channel blockers

Sodium channel blockers

Potassium channel blockers

106

Fluid in the pericardial cavity is called what?

Pericardial effusion

107

What are these areas?

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109

What is INR and how is it calculated?

International normalised ratio INR = (patient PT/normal PT)^ISI INR = (Patient prothrombin time/mean normal prothrombin time)^international sensitivity index

111

What effect does shifting the O2 saturation curve to the left have on Hb affinity for O2?

Increase

112

What condition is this?

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Aortic stenosis

113

Which substance mediates endothelial vasoconstriction in coagulation?

Endothelin

115

Describe 5 steps in the feedback loop of short term regulation of low blood pressure

1. Low blood pressure sensed by stretch receptors in carotid sinus in internal carotid artery

2. Less stretch causes less firing of glossopharyngeal nerve to nucleus of solitary tract in medulla

3. Sympathetic nervous system stimulated

4. Sympathetic nervous system:

- Increases heart rate (chronotropic)

- Decreases AV conduction time

- Increases cardiac contractility (inotropic) (more Ca2+ released per contraction)

- Increases TPR (alpha adrenocetpors)

- Increase venous tone (don't want blood hanging around uselessly in the veins)

5. Blood pressure increased

116

Define left ventriuclar hypertrophy

Increase in lefr ventricle mass relative to body size

117

How do beta blockers lower blood pressure?

 

Reduce cardiac output and renin release through antagonism of beta 1 +/- beta 2 adrenocetpors

 

118

How is left ventrilce relative wall thickness calculated?

T/D

Thickness of wall / Diametre of chamber

119

What percentage of the blood is in the lungs?

10%

120

What are 3 important qualities to establish when taking a history of palpitations?

1 Rhythm. Regular or irregular? Can you tap out the rhythm?

2. Rate. Faster or slower than normal?

3. Strength. Stronger or more forceful than normal?

121

What percentage of the blood is in the veins?

65%

122

List 8 actions of thrombin

Fibrinogen → fibrin V -> Va VIII -> VIIIa IX -> IXa XI -> XIa XIII -> XIIIa Binds to thrombomodulin (inhibits Va and VIIIa) Platelet activation

123

Which factors is vitamin K a co-factor for?

2, 7, 9, 10

ie the same cofactors that warfarin affects

124

 

A raised INR indicates which 2 possible things?

 

 

There is a problem with Factor VII or the patient is on warfarin

 

125

Define anaemia and which two blood tests are used most often in diagnosis

A reduction of the total circulating red cell mass below normal limits.

Haematocrit and haemoglobin concentration

126

Dietary deficiences of which 3 substances may cause anaemia?

Iron, VitB12, folate

128

What is the molecular action of calcium channel blockers?

 

Inhibit voltage-gated L-type Ca2+ channels

129

What effect does adrenaline have on TPR and how?

What receptors are involved?

Increases TPR due to vasoconstriction.

Stimulation of alpha adrenoceptors. 

130

A new drug called stortosartan is on the market. What class of drug is this likely to be?

Angiotensin receptor antagonist

132

Name 2 substances that may be elevated in blood after death of cardiac myocytes

 

Troponin I and T

Creatine kinase MB

 

133

What type of aneurysm is classically seen on the circle of Willis and what is this called?

Sacular aneurysm

Called a berry aneurysm

134

What is the most lateral structure in the mediastinum?

Phrenic nerves

135

At what vertebral level does the aorta pass behind the diaphragm?

T12

136

Identify these stages of the cardiac cycle

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137

What is a typical ESV?

40-50ml (Guyton and Hall, 1996)

138

What type of blood vessel is this?

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Small vein.

The wall of the vein consists of two to three layers of smooth muscle fibres. Note the wide diameter of the lumen relative to the thickness of the wall.

139

What type of blood vessel is this?

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Capillary

140

At what vertebral level does the inferior vena cava pass through the diaphragm?

T8

141

Name these volumes or pressures

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142

What is the molecular target of ACE inhibitors?

 

Block conversion of Angiotensin I to Angiotensin II by inhibiting angiotensin converting enzyme

 

143

Where does left anterior descending artery supply?

LAD supplies anterior surface and anterior 2/3 of interventricular septum 

144

Where does circumflex artery supply? 

lateral wall of LV

145

Where does posterior interventricular artery supply?

Inferior part of LV and posterior 1/3 of interventricular artery

146

How soon after an AMI will cardiac enzymes begin to possibly be elevated?

3 hours

147

How long after the event will cardiac enzymes be a sensitive measure of AMI? 

6 hours

148

How soon after an AMI must repurfusion be to be effective?

6 hours

149

Which artery most commonly supplies the atrio-
ventricular node?

Right coronary artery

150

What is the most common inherited genetic disease of hypercoagulability of blood?

Factor V Leiden mutation

151

Which bacteria classically causes subacute bacterial endocarditis?

Viridans strep

152

Why is aspirin given in low doses as a blood thinner?

Low dose maintains selectivity for platelets because it will be at a low concentration by the time it reaches endothelium

153

Why do some NSAIDs increase bleeding time?

They impair thromboxane A2, thus impairing platelet aggregation

154

Where is the SA node?

In the right atrium, at the top of the crista terminalis and sweeps across in front of the SVC

155

Where is the AV node

In the right atrium, between tricuspid valve and coronary sinus