genetics of arrhythmias Flashcards
1
Q
give examples of some channelopathies?
A
- congenital long QR syndrome
- brugada syndrome
2
Q
what are channelopathies?
A
- mutations in genes that encode the cardiac ion channels
- mainly affects repolarisation
- propensity to develop arrhythmia both atria and ventricular
3
Q
give some examples of cardiomyopathies?
A
- hypertrophic cardiomyopathy
- arrhyhtmogenic right ventricular cadiomyopathy
4
Q
what is congenital LQT syndrome?
A
- 1/2000 are carriers
- polymorphic VT (torsades de pointes) triggered by adrenergic stimulation
- risk associated with severity of QT syndrome
>440ms in males
>450ms in females - sutosomal dominant or recessive
5
Q
what are the trigger of Tdp/syncope?
A
- exercise
- sudden auditory stimuli
- sleep
- QTprolonging states
- medication
- hypokalaemia
6
Q
what is the pathway by which QT is prolonged?
A
- mutation
- 40 protein
- reduced ionic channels
- prolonged cardiac repolarisaion
- QT interval prolonged
7
Q
what is brugada syndrome?
A
- risk of polymorphic VT, VF
- AF common
- ST elevation and RBBB in V1-V3
- diagnostic ECG changes may be seen with flecainide or ajmalilne (drugs that block the cardiac sodium channel)
- 12 assoc genes: cardiac sodium channel and calcium channel
- autosomal dominant
8
Q
what are the VF trigggers for brugada?
A
- rest or sleep
- fever
- excessive alcohol, large meals
- genotype and family history of SCD does not influence prognosis
9
Q
what drugs must be avoided in brugada syndrome?
A
- antarrhythmic drugs
- psychotropics
- analgesics
- anaesthetics
10
Q
what are the ECG showings of hypertrophic cardiomyopathy?
A
- LVH
- LVstrain
11
Q
what is dilated cardiomyopathy?
A
- 1/2500
- males > females
- saceomere and desosomal gened
12
Q
what is arrhythmogenic right ventricular cardiomyopathy?
A
- fibro-fatty replacement of cardiomyoctyes
- LV involvement in >50% cases
- autosomal dominant
- 1/5000
