Inherited cardiac conditions Flashcards
What are the 3 main general types of inherited cardiac conditions?
Cardiomyopathies
Channelopathies
Aortopathy
What are the 3 main inherited cardiomyopathies?
Hypertrophic cardiomyopathy
Arrhythmogenic right ventricular cardiomyopathy
Dilated cardiomyopathy
What are the 3 main inherited channelopathies?
Congenital long QT syndrome
Brugada syndrome
Catecholaminergic polymorphic ventricular tachycardia (CPVT)
What are the 3 main aortopathies?
Marfan’s syndrome
Ehlers Danlos syndrome
Luiz Dietz syndrome
What are some common symptoms of inherited cardiac conditions?
palpitations
Syncope
breathlessness
Pre-syncope
Chest pain
Sudden death
What is meant by a channelopathy?
Mutation of genes coding for ion channel proteins
This leads to problems with conduction in the heart
Which ion channel is most commonly mutated in long QT syndrome?
Potassium channels
Which ion channel is most commonly mutated in Brugada syndrome?
Sodium channels
Which ion channel is most commonly mutated in catecholaminergic polymorphic ventricular tachycardia?
Ryanodine receptors (In Ca2+ induced Ca2+ release)
What is the prevalence of long QT syndrome?
1 in 2000
By how much is the QT interval elongated in long QT syndrome?
> 440ms in males
460ms in females
How many subtypes of long QT syndrome are there?
13
What is an example of an autosomal dominant subtype of long QT syndrome?
Isolated long QT syndrome = Romano-Ward syndrome
What is an example of an autosomal recessive subtype of long QT syndrome?
Jerrell and Lange-Nielsen syndrome (Associated with deafness)
What are some common symptoms of long QT syndrome?
Polymorphic VT (Torsades du pointes)
Lone AF
Heart block
Syncope
What are some common symptoms of arrhythmia in long QT syndrome?
Exercise
Sudden auditory stimuli
Sleep
Qt prolonging states due to medication or hypokalaemia
What are some T-wave patterns that may be seen on an ECG with a person with long QT syndrome?
Wise based, slowly generated T wave
Wide based, double hump T wave
Low amplitude deflection of descending limb of T-wave
What are some management strategies for long QT syndrome?
ß-Blockers
Avoidance of triggers
K+ infusions (Depending on mutation)
How many subtypes of Brugada syndrome are there?
12
Is Brugada syndrome autosomal recessive or dominant?
Dominant
What are the risks of Brugada syndrome?
Risk of Polymorphic Ventricular Tachycardia or Atrial Fibrillation
What are some examples of drugs that may exacerbate ECG changes in Brugada syndrome?
Flecainide
Ajmaline
This is because they both block sodium channels, making the imbalance worse
What some common triggers of Brugada syndrome?
Rest or sleep
Fever
Excessive alcohol or food intake
What are some management strategies for Brugada syndrome?
Avoidance of drugs that may induce changes to ECG
Avoidance of excessive alcohol
Treatment of fever with antipyretics
What are some drugs to avoid in Brugada syndrome?
Anti-arrhythmic drugs
Psychotropics
Analgesics
Anaesthetics
What occurs in Hypertrophic Obstructive Cardiomyopathy (HOCM)?
A mutation, mostly in sarcomeric genes, causes hypertrophy of the ventricular wall, which decreases the volume of the heart chambers
What are some common presentations of hypertrophic obstructive cardiomyopathy?
Sudden death
Heart failure
Angina
Atrial fibrillation
Can be asymptomatic
What causes dilated cardiomyopathy?
Mutation of sarcomeric, desmosomal and latin genes cause ‘floppy’ heart walls that do not properly contract
Which gene mutations in dilated cardiomyopathy are usually malignant?
Titin and Lamin C mutations
What is the management strategy for dilated cardiomyopathy?
A - ACEi or ARB
B - Bisoprolol
A - Aldosterone antagonist
L - Loop diuretic
What occurs in arrhythmogenic right ventricular cardiomyopathy?
Fibro-fatty replacement of cardiomyocytes in the right ventricle (Left ventricular involvement in <50% of cases)
Which gene mutations are autosomal dominant or recessive in arrhythmogenic right ventricular cardiomyopathy?
Autosomal dominant mutations in desmosomal genes
Autosomal recessive mutations in non-desmosomal genes
