M103 T3 Symposium sudden death 1 - Harry Witchel

Question 1

What are the systems that, when affected, can cause sudden death?

Answer 1

Heart and/or its vessels
Non cardiac vessels (stroke or aneurysm)
Pulmonary system (pulmonary embolism)
CNS - rare seizures in epilepsy

Question 2

What are the disorders leading to risks for sudden cardiac death?

Answer 2

CHD / low LVEF
structural heart disease (e.g. cardiomyopathies)
developmental/genetic structural pathologies of the heart
primary arrhythmia

Question 3

What are primary cardiac arrhythmias caused by?

Answer 3

mutations in genes primarily encoding ion channels

leads to a fundamental electrical failure of the heart that causes heart failure where it discontinues beating

Question 4

What is a Cardiac Arrest otherwise known as?

Answer 4

cardiopulmonary arrest

circulatory arrest

Question 5

What can an acute myocardial infarction sometimes cause?

Answer 5

cardiac arrest

Question 6

What can happen to the heart during an acute myocardial infarction?

Answer 6

usually it will continue pumping, but less effectively

Question 7

What are the broad categories of arrhythmia causes?

Answer 7

Electrical (Primary or Arrhythmogenic)
Structural
Ischaemic

Question 8

What are electrical arrhythmias caused by?

Answer 8

when there are problems with ion channels and electrical issues at cellular level
when there might be extra conduction pathways at the organ level

Question 9

What are structural arrhythmias caused by?

Answer 9

unusual shape or size of cardiac tissue that changes signal pathway

Question 10

What are ischaemic arrhythmias caused by?

Answer 10

when the patient has hypoxia
it makes local heart tissue electrically unstable
it effectively changes signal pathway, leading to delays that interfere with cardiac conduction cycle

Question 11

What can changes to the signal pathway in structural arrhythmias result in?

Answer 11

signal delays that interfere with cardiac conduction cycle

Question 12

What can changes to the signal pathway in structural arrhythmias result in?

Answer 12

signal delays that interfere with cardiac conduction cycle

Question 13

What are the causes of primary arrhythmia?

Answer 13

Unstable myocardium
Ion channel pathologies
Accessory conduction pathways

Question 14

What is an unstable myocardium caused by in a primary arrhythmia?

Answer 14

damaged or hypoxic tissue

Question 15

What is an example of an unstable myocardium caused by in a primary arrhythmia?

Answer 15

Atrial Fibrillation

Question 16

What is an example of a channelopathy?

Answer 16

Long QT syndrome

Question 17

What happens when Accessory conduction pathways malfunction?

Answer 17

sometimes the transmission of electrical signals along the heart goes in the reverse direction
so rather than going from the atria to the ventricles, it goes the other way

Question 18

If a patient’s QT intervals are longer than normal, what are they at risk of?

Answer 18

primary arrhythmia

Question 19

If a patient’s QT intervals are longer than normal, what are they at risk of?

Answer 19

primary arrhythmia

Question 20

What are the consequences of cardiomyopathy?

Answer 20

there is a risk of pumping dysfunction
there is a risk of low output heart failure
there is a risk of conduction abnormalities

Question 21

Why does cardiomyopathy cause negative effects?

Answer 21

bc the normal pathways of electrical conduction are altered

Question 22

What are the two types of cardiomyopathy?

Answer 22

Hypertrophic

Dilated

Question 23

What are other terms for hypertrophic and dilated cardiomyopathy?

Answer 23

hy - concentric

di - eccentric

Question 24

What are the differences between hypertrophic and dilated cardiomyopathy?

Answer 24

hy - any age or gender

di - most common in 20 - 60 year olds and in males

Question 25

What causes hypertrophic cardiomyopathy?

Answer 25

Inner LV chamber shrinks | Myocardium thickens

Question 26

What is an effect of hypertrophic cardiomyopathy?

Answer 26

Sudden death in young athletes

Question 27

What is an example of a developmental defect in the heart?

Answer 27

Tetralogy of Fallot

Question 28

What are two examples of developmental defects in the heart?

Answer 28

an extrasystole | a nearby focus of rapid firing

Question 29

What might be the causes for cardiac tissue becoming a substrate?

Answer 29

a predisposing factor | an electrical defect

Question 30

What are examples of structural defects in the heart?

Answer 30

fibrosis or inflammation caused by IHD

Question 31

What are examples of electrical defects in the heart?

Answer 31

genetic or pharmacological problems with ion channels or electrolytes

Question 32

What happens during an R on T?

Answer 32

a premature QRS complex occurs during the previous T wave

Question 33

What is the vulnerable period?

Answer 33

the T wave

Question 34

When does the vulnerable period occur?

Answer 34

During repolarisation of ventricular AP | Refractory period is ending

Question 35

What is the resulting QRS wave after the vulnerable period?

Answer 35

a premature ventricular contraction

Question 36

Which conditions are Implanted Electronic Devices mostly used to treat?

Answer 36

bradyarrhythmias | heart block

Question 37

What is the difference between and an Implanted Electronic Device and an Implantable Cardioverter Defibrillator?

Answer 37

electronic - applies electrical pulses on each beat | cardioverter - applies electrical impulses ONLY when ventricular dysrhythmias detected

Question 38

When might an implantable cardioverter defibrillator be implanted?

Answer 38

cardiac arrest due to ventricular fibrillation symptomatic heart failure with low LVEF Low output heart failure after MI (40 days later) cardiomyopathies congenital

Question 39

What is an example of a cardiomyopathy?

Answer 39

Dilated cardiomyopathy

Question 40

What is an example of a congenital reason for why an implantable cardioverter defibrillator be implanted?

Answer 40

Tetralogy of Fallot

Question 41

What is an example of a Channelopathy?

Answer 41

long QT syndrome

Question 42

What is the effect of antiarrhythmic drugs?

Answer 42

they usually affect ion channel activity or sympathetic drive

Question 43

What are examples of antiarrhythmic drugs?

Answer 43

Amiodarone | Beta blockers

Question 44

Which antiarrhythmias are antiarrhythmic drugs used for?

Answer 44

supraventricular arrhythmias | Arrhythmias arising from atria or AV node

Question 45

Which works least effectively, antiarrhythmic drugs or pacing or ICDs?

Answer 45

antiarrhythmic drugs

Question 46

What can reperfusion injury lead to?

Answer 46

electrical irregularities | risk of sudden cardiac death

Question 47

When might there be an increased risk of reperfusion injury?

Answer 47

in the myocardium after percutaneous coronary intervention | in the brain tissue after an ischaemic stroke

Question 48

How does reperfusion injury occur?

Answer 48

circulation is restored | this results in inflammation and oxidative damage

Question 49

What are preventative treatments for reperfusion injury?

Answer 49

Cooling Immunosuppression - to prevent inflammation Oxygen radical scavengers

Question 50

How do xxygen radical scavengers work to stop oxygen radicals in reperfusion injury?

Answer 50

they pick up oxygen radicals and and get rid of their electrons so it prevents the oxygen radicals from causing a chain reaction of damage

Question 51

What are both syncope and seizures associated with?

Answer 51

a loss of consciousness | the symptoms are described as “black outs”

Question 52

What can delay the diagnosis of syncope and seizures?

Answer 52

figuring out which condition matches the symptoms bc they're so similar Can be difficult to differentiate from a patient’s description

Question 53

When does syncope occur?

Answer 53

when the heart and the vessels aren't supplying blood to the brain effectively

Question 54

What visual effects do seizures tend to be associated with?

Answer 54

stiffness unusual postures/ movements patients “tip over”

Question 55

What visual effects does syncope tend to be associated with?

Answer 55

patients crumple into themselves

Question 56

How might a seizure or syncope patient present which might make it hard to diagnose?

Answer 56

might have nothing abnormal on examination

Question 57

How is syncope recognised in a patient?

Answer 57

it might be registered by Holter monitor

Question 58

How do Holter monitors work?

Answer 58

involves measuring their ECG for either 24 hrs or up to five or seven days

Question 59

How are seizures recognised in a patient?

Answer 59

an EEG | a brain scan

Question 60

What does an electroencephalogram involve?

Answer 60

electrodes on the scalp

Question 61

Why are brain scans used in regard to seizures?

Answer 61

when seizures are caused by underlying structural abnormalities, the brain imaging can sometimes show what might be causing the seizures

Question 62

Why are brain scans used in regard to seizures?

Answer 62

when seizures are caused by underlying structural abnormalities, the brain imaging can sometimes show what might be causing the seizures

Question 63

What causes the different ways in which syncope and seizure patients fall?

Answer 63

syn - crumple - bc the brain has lost all power so it loses control of all the muscles seiz - tip over - bc the brain is over active, patients remain stiff

Question 64

Which condition features the same effects as a normal seizure?

Answer 64

convulsive syncope

Question 65

What are two common types of syncope?

Answer 65

Exertional syncope | Vasovagal Syncope

Question 66

What is Vasovagal Syncope associated with?

Answer 66

Vagal increase (& symp decrease) vasodilatation low heart rate

Question 67

Where in the body are Vasovagal Syncopes triggered from?

Answer 67

centrally - the brain | not triggered at level of heart

Question 68

What causes Vasovagal Syncope?

Answer 68

the physiological changes in the body that vasovagal syncope is associated with leads to a pressure drop throughout the NS so blood will stop going uphill against gravity and will not go to the brain

Question 69

What is the most common form of syncope?

Answer 69

Vasovagal Syncope

Question 70

What group is Vasovagal Syncope most common in?

Answer 70

in young adults

Question 71

Where in the body are Vasovagal Syncopes triggered from?

Answer 71

it has neurogenic origin

Question 72

What does the Number Needed to Treat indicate?

Answer 72

describes how good / bad / effective a particular treatment might be IOT to compare it to other treatments

Question 73

What happens if a mutation in the gene responsible for a particular autosomal dominant disorder has 95% penetrance?

Answer 73

95% of those with the mutation will develop the disease, while 5% will not

Question 74

What happens if a mutation in the gene responsible for a particular autosomal dominant disorder has 95% penetrance?

Answer 74

95% of those with the mutation will develop the disease, while 5% will not