Genetics of SCD Flashcards
Define SCD?
“An unexpected death without obvious extra-cardiac cause that occurs in association with a witnessed rapid collapse or within 1 hour of the onset of symptoms”
Causes of SCD?
Coronary heart disease Cardiomyopathies Inherited arrthymia syndrome Valvular heart disease Channelopathies
Talk though age of onset in terms of some of the common diseases causing SCD?
Teens: Long QT syndrome, Catecholaminergic Polymorphic Ventricular Tachycardia.
Twenties: HCM, Arrythmogenic Right Ventricular Cardiomyopathy.
Thirties: Non-ischaemic dilated cardiomyopathy, ERS/BrS
Three inherited cardiomyopathies?
HCM
NIDCM
ARVC
Incidence and diagnosis of HCM?
1 in 500
LV wall thickness of more than 15 mm in more than 1 segment.
Risk factors for HCM leading to death?
A history of unexplained syncope,
Fhx of SCD,
a maximal LV wall thickness of ≥30mm, repetitive non-sustained VT,
abnormal blood pressure response to exercise
Any gender difference in HCM?
Yes - to male. This may be bias due to reporting.
Non-ischaemic dilated cardiomyopathy - define
LV dilatation and LV systolic dysfunction in the absence of abnormal loading conditions (HTN, valve dx) or coronary artery disease sufficient to cause global systolic impairment
Arrthymogenic Right Ventricular Cardiomyopathy - what is it?
Fibrofatty replacement of the RV myocardium.
Much rarer and sadly SCD may be the first arrthymic event in 50% of pts.
Arrthymogenic Right Ventricular Cardiomyopathy - inheritance?
AD - incomplete penetrance
Cardiomyopathy - ECG signs?
T wave inversion in the lateral leads
4 common primary electric disorders?
- Long QT syndrome
- Short QT syndrome
- Brugada syndrome
- Catecholaminergic polymorphic ventricular tachycardia.
What is catecholaminergic polymorphic ventricular tachycardia?
When diagnosed etc?
Polymorphic VT induced by physical or emotional stress.
Usually diagnosed during 1st/2nd decade of life.
Only sign: lower HR at rest, unless having an episode.
What is Brugada syndrome?
Sodium channel mutation.
At risk of polymorphic VT/VF.
AF common.
ECG sign of Brugada?
ST segment elevation and RBBB in V1-3.
