Inherited cardiac conditions

Question 1

What are the 3 main general types of inherited cardiac conditions?

Answer 1

Cardiomyopathies
Channelopathies
Aortopathy

Question 2

What are the 3 main inherited cardiomyopathies?

Answer 2

Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Dilated cardiomyopathy

Question 3

What are the 3 main inherited channelopathies?

Answer 3

Congenital long QT syndrome
Brugada syndrome
Catecholaminergic polymorphic ventricular tachycardia (CPVT)

Question 4

What are the 3 main aortopathies?

Answer 4

Marfan’s syndrome
Ehlers Danlos syndrome
Luiz Dietz syndrome

Question 5

What are some common symptoms of inherited cardiac conditions?

Answer 5

palpitations
Syncope
breathlessness
Pre-syncope
Chest pain
Sudden death

Question 6

What is meant by a channelopathy?

Answer 6

Mutation of genes coding for ion channel proteins
This leads to problems with conduction in the heart

Question 7

Which ion channel is most commonly mutated in long QT syndrome?

Answer 7

Potassium channels

Question 8

Which ion channel is most commonly mutated in Brugada syndrome?

Answer 8

Sodium channels

Question 9

Which ion channel is most commonly mutated in catecholaminergic polymorphic ventricular tachycardia?

Answer 9

Ryanodine receptors (In Ca2+ induced Ca2+ release)

Question 10

What is the prevalence of long QT syndrome?

Answer 10

1 in 2000

Question 11

By how much is the QT interval elongated in long QT syndrome?

Answer 11

> 440ms in males
460ms in females

Question 12

How many subtypes of long QT syndrome are there?

Answer 12

13

Question 13

What is an example of an autosomal dominant subtype of long QT syndrome?

Answer 13

Isolated long QT syndrome = Romano-Ward syndrome

Question 14

What is an example of an autosomal recessive subtype of long QT syndrome?

Answer 14

Jerrell and Lange-Nielsen syndrome (Associated with deafness)

Question 15

What are some common symptoms of long QT syndrome?

Answer 15

Polymorphic VT (Torsades du pointes)
Lone AF
Heart block
Syncope

Question 16

What are some common symptoms of arrhythmia in long QT syndrome?

Answer 16

Exercise
Sudden auditory stimuli
Sleep
Qt prolonging states due to medication or hypokalaemia

Question 17

What are some T-wave patterns that may be seen on an ECG with a person with long QT syndrome?

Answer 17

Wise based, slowly generated T wave
Wide based, double hump T wave
Low amplitude deflection of descending limb of T-wave

Question 18

What are some management strategies for long QT syndrome?

Answer 18

ß-Blockers
Avoidance of triggers
K+ infusions (Depending on mutation)

Question 19

How many subtypes of Brugada syndrome are there?

Answer 19

12

Question 20

Is Brugada syndrome autosomal recessive or dominant?

Answer 20

Dominant

Question 21

What are the risks of Brugada syndrome?

Answer 21

Risk of Polymorphic Ventricular Tachycardia or Atrial Fibrillation

Question 22

What are some examples of drugs that may exacerbate ECG changes in Brugada syndrome?

Answer 22

Flecainide
Ajmaline
This is because they both block sodium channels, making the imbalance worse

Question 23

What some common triggers of Brugada syndrome?

Answer 23

Rest or sleep
Fever
Excessive alcohol or food intake

Question 24

What are some management strategies for Brugada syndrome?

Answer 24

Avoidance of drugs that may induce changes to ECG
Avoidance of excessive alcohol
Treatment of fever with antipyretics

Question 25

What are some drugs to avoid in Brugada syndrome?

Answer 25

Anti-arrhythmic drugs Psychotropics Analgesics Anaesthetics

Question 26

What occurs in Hypertrophic Obstructive Cardiomyopathy (HOCM)?

Answer 26

A mutation, mostly in sarcomeric genes, causes hypertrophy of the ventricular wall, which decreases the volume of the heart chambers

Question 27

What are some common presentations of hypertrophic obstructive cardiomyopathy?

Answer 27

Sudden death Heart failure Angina Atrial fibrillation Can be asymptomatic

Question 28

What causes dilated cardiomyopathy?

Answer 28

Mutation of sarcomeric, desmosomal and latin genes cause 'floppy' heart walls that do not properly contract

Question 29

Which gene mutations in dilated cardiomyopathy are usually malignant?

Answer 29

Titin and Lamin C mutations

Question 30

What is the management strategy for dilated cardiomyopathy?

Answer 30

A - ACEi or ARB B - Bisoprolol A - Aldosterone antagonist L - Loop diuretic

Question 31

What occurs in arrhythmogenic right ventricular cardiomyopathy?

Answer 31

Fibro-fatty replacement of cardiomyocytes in the right ventricle (Left ventricular involvement in <50% of cases)

Question 32

Which gene mutations are autosomal dominant or recessive in arrhythmogenic right ventricular cardiomyopathy?

Answer 32

Autosomal dominant mutations in desmosomal genes Autosomal recessive mutations in non-desmosomal genes