inherited cardiac conditions ICC

Question 1

cardiomyopathy

Answer 1

a heart muscle abnormality

• hypertrophic cardiomyopathy
• ARVC (arrhythmogenic right ventricular cardiomyopathy)
• idiopathic dilated cardiomyopathy

Question 2

channelopathy

Answer 2

heart rhythm abnormality

• long QT syndrome
• Brugada syndrome
• catecholaminergic polymorphic ventricular tachycardia (CPVT)
• short QT syndrome
• progressive familial conduction disease
• familial AF
• familial WPW

Question 3

aortopathy

Answer 3

arterial blood vessel abnormality

• marfans syndrome
• Ehlos Danlos

Question 4

presentation of ICC

Answer 4

very variable
-can seem normal and have no phenotype of the disease (ie carrier status)
-symptoms usually related to underlying condition ie arrhythmia or HF
>heart rhythms involves = palpitations, presyncope, syncope, breathlessness, chest pain, sudden death
>cardiomyopathy related = congestive HF, breathlessness, peripheral oedema, orthopnoea weakness, may be systolic HF or diastolic

Question 5

what are channelopathies

Answer 5

mutations in genes that encode cardiac ion channels
-abnormal cardiac cellular electrophysiology
-mainly affecting repolarisation
>shows abnormalities on the ECG
>normal cardiac structure and function
>propensity to develop arrhythmia - both atrial and ventricular

Question 6

the surface ECG =

Answer 6

summation of all ion currents across the cell membrane

Question 7

congenital long QT syndrome (cLGTS) 1

Answer 7

on ECG: QTc interval prolongation is >440ms in males
>450ms in females
there are 13 subtypes
»Autosomal dominant - isolated LQT : romano - ward syndrome
»autosomal recessive : associated with deafness : jervell and lange - nielsen syndrome

Question 8

cLQTS 2

Answer 8

> hallmark arrhythmia is polymorphic VT
or Lone AF / heartblock
presenting complaints usually include syncope SCD in children and young adults
triggers of TdP syncope = exercise, sudden auditory stimuli, sleep, QT prolonging states ie medication and hypokalaemia

Question 9

molecular basis of LGT

Answer 9

faulty mRNA > abnormal protein and function >reduced no of ion channels or normal number of ion channels but with abnormal function > prolonged cardiac depolarising currents > shows as QT interval prolongation
» there are external triggers ie hypokalaemia = polymorphic ventricular tachycardia

Question 10

cQLTS management

Answer 10

BBs are effective at reducing SCD
avoid QT prolonging drugs
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 11

LGTS type 2

Answer 11

when given potassium the ECG became normal ie normalisation of QT prolongation

Question 12

brugada syndrome

Answer 12

risk of polymorphic VT, VF
AF is common
ST elevation and RBBB in v1-v3
ECG findings may be intermittent/change over time
diagnostic ECG changes may seen only with provocative testing with flecainide or ajmaline (drugs that block cardiac sodium channel)
12 associated genes
Is autosomal dominant most common in adults 8x more likely to preset in males

Question 13

brugada syndrome 2

Answer 13

VF triggers = usually at rest or sleep
fever
excessive alcohol or large meals or both !
genotype and family history of SCD does not influence prognosis

Question 14

SCD

Answer 14

sickle cell disease

Question 15

brugada syndrom management

Answer 15

avoidance of drugs that may include Brugada changes on ECG
avoidance of excessive alcohol and large meals
prompt treatment of fever with anti-pyretic medications
ICD if Ventricular arrhythmia

Question 16

brugada syndrom management

Answer 16

avoidance of drugs that may include Brugada changes on ECG
avoidance of excessive alcohol and large meals
prompt treatment of fever with anti-pyretic medications
ICC if Ventricular arrhythmia

Question 17

hypertrophic cardiomyopathy (HOCM)

Answer 17

can be caused by faulty genes (sarcomeric protein gene mutation) but can also be caused by other genetic/non-genetic causes ie amyloidosis

Question 18

clinical presentation of HOCM

Answer 18

sudden death !
HF
angina
AF
asymptomatic

Question 19

dilated cardiomyopathy

Answer 19

seen more commonly in males
-sarcomere and desmosomal genes (lamin genes)
-titin and lamin C mutations tend to be malignant
>the management of dilated cardiomyopathy is the same as HF

Question 20

Arrhythmogenic right ventricular cardiomyopathy

Answer 20

fibro-fatty replacement of cardiomyocytes in the RV
LV involvement sometimes
»Autosomal dominant mutations in the genes for desmosomal proteins
»autosomal recessive mutations in nondesmosomal genes
>treat if high SCD risk with ICD

Question 21

management of ICDs

Answer 21

> diagnosis = clinical and genetic testing
risk management = risk, lifestyle, pharmacological and non-pharmacological intervention
family cascade screening

Question 22

importance of presymptomatic identification of individuals at risk of SCD

Answer 22

SCD may be the only presentation
young age groups are at risk
family members are also at risk
>effective therapies are available

Question 23

diagnosis of ICD

Answer 23

mutation normally found
absence of mutation does not exclude gene
>often a gene variant of unknown significance
»diagnosis relies on combination of clinical and genetic testing - a multidisciplinary approach

Question 24

diagnosis of ICC

Answer 24

mutation normally found
absence of mutation does not exclude gene
>often a gene variant of unknown significance
»diagnosis relies on combination of clinical and genetic testing - a multidisciplinary approach

Question 25

lifestyle and triggers for SAD (sudden arrhythmic death) in ICCs

Answer 25

sports and physical activity
diet and alcohol
medications
>there are specific triggers in different types of ICC

Question 26

lifestyle changes for

- LQTS

Answer 26

diet = potassium rich foods ie bananas
caution if diarrhoea and vomitting 
don't ! hold breath underwater 
and avoid sudden loud noises 
>> avoid !!
ant depressants , antibiotics and antihistamines

Question 27

lifestyle changes for brigade syndrome

Answer 27

avoid excessive alcohol

and prompt treatment of fevers

Question 28

competitive sport and ICCs

Answer 28

3x the risk of SAD if you play a competitive sport
certain ICCs are at higher risk
different risk with different sport

Question 29

exercise in ICCs

Answer 29

is good !
prevents CVD diabetes HRT
psychological well being

Question 30

patient centre exercise programmes

Answer 30

they involve:
patient factors ie ICC type, disease severity, Fx, ICD
exercise factors ie type of exercise
intensity , duration, frequency
personal factors ie
personal preference , quality of life , psychological impact

Question 31

what are S-ICDs

Answer 31

subcutaneous intra cardiac device

is a defibrillator

Question 32

S-ICD vs Transvenous ICD

Answer 32

S-ICD = prevention of vascular complications
better cosmetic and functional outcome
lead extraction safe
Trans ICD = high risk of vascular complications in later life
cosmetic and fucntional issues related to seatbelts etc
lead extraction has high risk

Question 33

what to do after SCD

Answer 33

make diagnosis

assess relatives for disease and risk !

Question 34

how to make a diagnosis

Answer 34

DNA retention for genetic post - mortem

clinical and genetic testing of family members

Question 35

what is cascade screening

Answer 35

its concerned with familial gene identification
>produces a greater rate of case identification than general population screening
>once diagnosis is confirmed in an individual, testing is extended to first degree and second degree relatives
>then if these relatives test positive - their first and second … etc

Question 36

ICC issues in young

Answer 36

psycho-social impact

lifestyle is jeopardised