Cardiac Myopathies & Channelopathies Flashcards Preview

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Flashcards in Cardiac Myopathies & Channelopathies Deck (58):
1

What is a cardiomyopathy?

A problem with heart muscle

2

What types of congenital heart defects are there?

Structural

Cardiomyopathies

Channelopathies

3

All cardiomyopathies will present themselves within the first few years of life. True or false?

False!

They can start to develop at any age.
Some people have no abnormalities for many years and suddenly one starts to manifest itself

4

Who do we screen for congenital heart defects?

People who have affected first degree relatives

Groups at risk of mortality: athletes

5

List some cardiomyopathies.

Hypertrophic
Dilated
L ventricle non-compaction
Arrhythmogenic

6

Describe some other non heart specific conditions that can cause CVS diseases.

Palmoplantar keratoderma

Marfan's syndrome:
Can cause an aortic root aneurysm

Familial Hypercholestrolaemia:
Can't take up cholesterol from blood due to an LDL receptor fault. Excess blood cholesterol = heart problems

7

List some Channelopathies.

Long QT
Short QT
Brugada
CPVT

8

What are the features of hypertrophic cardiomyopathy?

Thick walls, small cavities

When they contract the atria & ventricles contract down to almost nothing

Disorganised arrangement of myocytes

Fibrotic tissue develops: arrhythmias

9

Why does fibrotic tissue cause arrhythmias?

Fibrotic tissue is an electrical insulator, so it blocks electrical conduction in the heart.

Causes random bursts of ventricular arrhythmias

10

How do patients with hypertrophic cardiomyopathy present?

Sudden death
Angina
Dyspnoea
Palpitations
Syncope
Jerky pulse
Harsh ejection systolic murmur

11

What tests can you do to confirm hypertrophic cardiomyopathy?

ECG: shows up the random bursts of ventricular arrhythmia

Echo: shows up the hypertrophic walls

Exercise test with heart monitor

12

What is the treatment of hypertrophic cardiomyopathy?

Beta blockers or verapamil (a Ca antagonist): to reduce ventricular contractility

Amiodarone: anti-arrhythmic drug


Anti-coagulants: to prevent a clot forming as a result of arrhythmia

Septal myomectomy

Implantable defribrillator

13

What is septal myomectomy? How is it done?

Removal of a portion of the septum that is obstructing the flow of the blood from the ventricle to the aorta

Can be done surgically or chemically (alcohol ablation)

14

What is an implantable defibrillator?

A device placed in the heart that senses and corrects any arrhythmias that occur

It corrects them by giving electric shocks to get the heart back into a normal rhythm

15

Which type of cardiomyopathy causes the most sudden deaths?

Hypertrophic

16

What are the features of dilated cardiomyopathy?

A dilated, flabby heart
Thin walls
Chambers don't contract properly

17

How do patients with dilated cardiomyopathy present?

They present very young with heart failure

Breathless
Fatigue
Fluid retention
Emboli

18

What are the clinical signs of dilated cardiomyopathy?

Raised pulse
Low BP
Raised JVP
S3 gallop
Mitral or tricuspid regurgitation
Pleural effusion

19

What tests can you do to confirm dilated cardiomyopathy?

Bloods:
Look for B-natriuretic peptide which will be raised
U&E: low Ca2+

CXR: cardiomegaly, pulmonary oedema

ECG: tachycardia

Echo: flabby, dilated heart

20

What is the significance of low Ca2+ in dilated cardiomyopathy?

Low Ca2+ indicates a poor prognosis

21

What is the treatment of dilated cardiomyopathy?

Bed rest

Diuretics

Digoxin: cardiac stimulant

ACE inhibitors

Anti-coagulants

Transplant

22

What are the features of left ventricle non-compaction?

The inside of the heart is sponge like during development and is compacted prior to birth to leave chambers

In this condition there's a fault in the compaction process and the inside of the heart, especially the L ventricle remains spongy and there are excessively prominent trabeculations

This causes poor pumping performance

23

How do patients with left ventricle non-compaction present?

Heart failure symptoms
SOB
Oedema
Fatigue
Exercise intolerance

Tachycardia
Blood clot formation

24

How is left ventricle non-compaction diagnosed?

When the trabeculations are more than twice as thick as the underlying ventricular wall

25

What tests can you do to confirm left ventricle non-compaction?

Echo
CT
PET
MRI
to look at the trabeculations

26

What is the treatment of left ventricle non-compaction?

ACE inhibitors
B-blockers
Aspirin

Implantable pacemaker

Heart valve replacement

Heart transplant

27

What is palmoplantar keratoderma?

A syndrome causing abnormal thickening of palms and soles when there is minor trauma

It also causes cardiomyopathy: fibro-fatty replacement of the right ventricle

Fibro-fatty tissue causes arrhythmias

28

What is a channelopathy?

Disturbed function of ion channels or the proteins that regulate them

Cardiac Channelopathies appear normal on a scan but abnormal on ECG

29

What are the features of long QT?

There are a few different forms

Q - T segment is longer than it should be

You get random bursts of ventricular arrhythmias

30

What can cause a cardiac arrest in patients with Long QT?

Stress
Sudden noise
Strenuous exercise
Slow HR during sleep

Drugs: a huge list of drugs that can trigger a cardiac arrest

31

What is the pathophysiology of Long QT?

Flow of ions in and out of cardiac myocytes generates the heart's electrical activity

In Long QT flow of potassium ions out of cardiac myocytes is delayed

This means that after each heartbeat the heart takes longer to repolarise (reset itself)

32

What are the causes of Long QT?

Inherited

Drug induced

Anorexia: due to dangerous electrolyte imbalances

33

Which gender is more commonly affected by Long QT?

Females

34

What are the symptoms of Long QT syndrome?

Sudden death
Asymptomatic

Blackouts
Seizures
Arrhythmia: torsade de pointes
Ventricular fibrillation

35

What is torsade de pointes arrhythmia?

A type of arrhythmia that can lead to sudden cardiac arrest

It is a ventricular tachycardia

36

What is ventricular fibrillation?
Why is it so dangerous?

Uncoordinated contraction of the cardiac muscle of the ventricles

The heart quivers rather than contracts

This means that the heart can't pump blood around the body properly as there's no contraction occuring

37

What is the treatment for Long QT?

Drugs: B-blockers

Implantable cardioverter-defibrillator (ICD) that can detect and correct arrhythmias

Avoid trigger: strenuous exercise, loud noises

38

Investigations of Long QT?

ECG

History: syncope, blackouts etc.

Family history of Long QT, sudden death

39

What are the features of short QT?

QT segment is shorter than it should be

Abnormal heart beat

V-fib

40

What are the symptoms of short QT?

Palpitations
Unexplained syncope
V-fib
Sudden death

41

What is the pathophysiology of short QT?

Increased activity of K channels in cardiac myocytes, so K ions flow out of the cells quicker than they should

This alters the electrical activity of the heart

42

What causes short QT?

Inherited genetic mutations

43

What is the treatment for short QT?

Implantable cardioverter-defibrillator (ICD)
Detects and corrects arrhythmias

Anti-arrhythmic agents: quinidine

44

Investigations of Short QT?

ECG

History of blackouts etc.

Family history

45

What are the features of Brugada Syndrome?

Arrhythmias caused by problems with the electrical activity of the heart

46

What are the symptoms of Brugada Syndrome?

Blackouts
Seizures
Heart palpitations
V or A-fib
Sudden death

47

Which type of people are mot affected by Brugada Syndrome?

Males
Young and middle age
Japanese & SE Asian descent

48

What is the pathophysiology of Brugada Syndrome?

Genetic mutations that cause problems with ion channels in the heart, which causes problems with heart contraction

There are a few mutations that cause Brugada, one of which reduces the flow of sodium ions into the cell

49

Investigations of Brugada.

ECG: does not always show up problems, need to give a drug that will help to show up the problem

Genetic testing

50

What drug can be used to show up problems on an ECG when diagnosing Brugada? How does it work?

Ajmaline: an anti-arrhythmic
It blocks sodium channels

It will show up any abnormalities of heart electrical activity on an ECG

51

How do you treat Brugada?

ICD pacemaker

No drugs available

Avoid triggers: fever, diarrhoea, many more

52

What does ICD pacemaker stand for?

Implantable cadioverter defibrillator

53

What does CPVT stand for?

Catecholaminergic polymorphic ventricular tachycardia

54

What are the features of CPVT?

Ventricular tachycardia that arises during times when they have high adrenaline levels (catecholaminergic)

Can cause fainting or sudden death

55

What are the symptoms of CPVT?

Associated with exercise, emotion, things associated with high adrenaline levels

Syncope
Blackouts

Seizures - if V tachycardia persists

If it persists further, V-fib can develop
Sudden death

56

Investigations for CPVT.

ECG is not helpful on its own

Stress test: stress the heart using exercise or catecholamines

This will show up premature ventricular contractions which can sometimes progress into ventricular tachycardia

57

What is polymorphic ventricular tachycardia?

A form of ventricular tachycardia where there are QRS complexes varying in amplitude, axis and direction

58

With the Channelopathies, how come sometimes only syncope occurs and other times death occurs?

When the heart goes into ventricular tachycardia, sometimes it corrects itself and the heart goes back to normal sinus rhythm

Sometimes it doesn't and the heart goes into V-fib and can't usually get out of this without medical intervention

This is when death occurs