Inherited Cardiac Conditions

Question 1

Symptoms related to the underlying condition

Answer 1

Heart rhythm: palpitations, fast heart beat, faints, breathlessness, chest pain
Heart muscle weakness: breathlessness, swollen legs, weakness
Sudden death

Question 2

Name the Channelopathies

Answer 2

Congenital Long QT syndrome
Brugada Syndrome
Catecholaminergic Polymorphic Ventricular tachycardia (CPVT)
Short QT syndrome

Question 3

Name the Cardiomyopathies

Answer 3

Hypertrophic cardiomyopathy
Arrhythmogenic Right Ventricular cardiomyopathy (ARVC)
Dilated cardiomyopathy

Question 4

describe the pathophysiology of channelpathies?

Answer 4

Mutation in genes that encode the cardiac ion channels.
Abnormal cardiac cellular electrophysiology
Mainly affecting repolarization
Abnormalities on the ECG
Normal cardiac structure and function
Propensity to develop arrhythmia both atrial and ventricular
Watch out if AF occurs in a young person

Question 5

Name the hallmark arrhythmia congenital long QT syndrome

Answer 5

arrhythmia is polymorphic VT (Torsades de Pointes VT)

Question 6

presenting complaint of congenital long QT syndrome

Answer 6

Primary presenting complaint : Syncope, SCD in children and young adults

Question 7

triggers of Torsades de pointes VT syncope

Answer 7

Exercise
Sudden auditory stimuli
Sleep
QT prolonging states 
Medication
hypokalaemia

Question 8

treatment of congenital long QT syndrome

Answer 8

Beta blockers –very effective at reducing SCD
Avoid QT prolonging drugs www.crediblemed.org
Avoidance of triggers
-strenuous swimming
-Breath holding
-Loud sudden noises
Correction of electrolyte abnormalities, maintenance of serum K at upper limit of normal range.

Question 9

what arrhythmias are ccommon in Brugada Syndrome

Answer 9

Risk of polymorphic VT, VF

Atrial fibrillation common

Question 10

What does ECG show for Brugada?

Answer 10

ST elevation and RBBB in V1-V3

ECG findings may be intermittent, change over time

Question 11

what are the associated genes for Brugada?

Answer 11

12 associated genes: Cardiac sodium channel (SCN5A) and calcium channel (CACN1Ac )

Question 12

what type of genetic inheritance is it?

Answer 12

Autosomal dominant: Adults, 8x males

Question 13

What are triggers for brugada syndrome?

Answer 13

VF Triggers:
-Usually rest or sleep
-Fever
 -Excessive alcohol,
 -large meals
Genotype and family history of SCD does not influence prognosis

Question 14

Treatment brugada

Answer 14

Avoidance of drugs that may induce Brugada changes on ECG.

Avoidance of excessive alcohol and large meals.

Prompt treatment of fever with anti pyretic medications

ICD if ventricular arrhythmia

Question 15

Drugs to avoid in Brugada

Answer 15

Anti-arrhythmic drugs (beta blockers may aggravate ECG changes, therefore only under supervision).
Psychotropics
Analgesics
Anaesthetics

Question 16

What is hypertrophic cardiomyopathy caused by/

Answer 16

mutation in sarcomeric genes

Question 17

more males/females tend to have dilated cardiomyopathy?

Answer 17

males

Question 18

what genes are involved in dilated cardiomyopathy?

Answer 18

Sarcomere and desosomal genes, laminA/C and desmin if there is conduction disease, dystrophin if X-linked

Question 19

what is arrhythmogenic RV cardiomyopathy?

Answer 19

Fibro-fatty replacement of cardiomyocytes.

Question 20

what genes cause arrhythmic RV cardiomyopathy?

Answer 20

Autosomal dominant mutations in the genes for desmosomal proteins; autosomal recessive mutations in nondesmosomal genes

Question 21

How is an ICC diagnosed?

Answer 21

Mutation found in 20-60% of ICC
Absence of a mutation does not exclude gene (? Other unknown gene/untested gene).
Often a gene variant found, of unknown significance
Diagnoses relies on combination of clinical and genetic testing: A mutlidisciplinary approach (geneticists and cardiologists)

Question 22

Lifestyle changes for long QT syndrome?

Answer 22

Diet: potassium rich foods (bananas, beans, oranges, green leafy vegetables, nuts)
Diarrhoea, vomiting
Underwater breath holding.
Avoiding sudden loud noises.

Question 23

Lifestyle changes for Brugada Syndrome?

Answer 23

Excessive alcohol

Prompt treatment of fevers

Question 24

medications for long QT syndrome to avoid?

Answer 24

Anti depresants, antibiotics, antihistamines

Question 25

what is the risk associated with competitive sport?

Answer 25

3X risk of sudden death

Question 26

why is an S-ICD better than a transverse ICD?

Answer 26

Prevention of vascular complications
Better cosmetic and functional outcome
Lead extraction safe