what is the name of a single gene mutation?
monogenic mutation
what type of inheritence are genetic predispositions usually the result of?
polygenic inheritance
what is hypertrophic cardiomyopathy?
increased thickness of cardiac wall causing cavity space to be lost
why is there a lot of scarring within a heart with hypertrophic cardiomyopathy?
because there is not enough blood supply to provide for such a big muscle- ischaemia
why are arrhythmias (particularly re-entry) common in a heart with hypertrophic cardiomyopathy?
scarring leads to arrhythmias due to increased automacity of surrounding tissue
when does a hypertrophic cardiomyopathy become apparent?
late teens/early twenties
what is dilated cardiomyopathy?
heart cavity dilation and thinning of the ventricular walls
what is the early form of dilated cardiomyopathy?
left ventricular enlargement
what are the 4 major primary cardiomyopathies?
hypertrophic cardiomyopathy (HCM) dilated cardiomyopathy (DCM) arrhythmogenic right ventricular cardiomyopathy (ARVC) restrictive cardiomyopathy (RCM)
what is arrhythmogenic right ventricular cardiomyopathy?
heart tissue is progressively replaced by fibrous and fatty tissue
what is restrictive cardiomyopathy?
a disorder of the heart muscle in which walls of the ventricles become stiff but not necessarily thickened so resist normal filling with blood, causes reduced EDV
which of the 4 cardiomyopathies has the greatest genetic link?
hypertrophic cardiomyopathy
what type of inheritance is hypertrophic cardiomyopathy?
autosomal dominant with variable penetrance
what type of inheritance is dilated cardiacmyopathy?
commonly autosomal dominant trait
sometimes autosomal recessive
what are the most common secondary syndromes of cardiomyopathies?
arrhythmias
heart failure
what is long QT syndrome?
a inherited condition where patients have a prolonged QT interval (ie relaxation of the ventricles)
what very lethal type of VT do patients with long QT syndrome have a predisposition to?
torsades de pointes
what occurs just before a torsades de pointes rhythm?
pause then an ectopic beat
what is the treatment for low risk patients with inherited long QT syndrome?
lifestyle + betablockers
what is the treatment for high risk patients with inherited long QT syndrome?
lifetsyle + ICD
+/- beta blockers
what is the cause of brugada syndrome?
cardiac sodium channel mutation
what is the main cause of sudden cardiac death in the elderly?
acquired heart disease
