Inherited Cardiac Conditions Flashcards
Symptoms related to the underlying condition
Heart rhythm: palpitations, fast heart beat, faints, breathlessness, chest pain
Heart muscle weakness: breathlessness, swollen legs, weakness
Sudden death
Name the Channelopathies
Congenital Long QT syndrome
Brugada Syndrome
Catecholaminergic Polymorphic Ventricular tachycardia (CPVT)
Short QT syndrome
Name the Cardiomyopathies
Hypertrophic cardiomyopathy
Arrhythmogenic Right Ventricular cardiomyopathy (ARVC)
Dilated cardiomyopathy
describe the pathophysiology of channelpathies?
Mutation in genes that encode the cardiac ion channels.
Abnormal cardiac cellular electrophysiology
Mainly affecting repolarization
Abnormalities on the ECG
Normal cardiac structure and function
Propensity to develop arrhythmia both atrial and ventricular
Watch out if AF occurs in a young person
Name the hallmark arrhythmia congenital long QT syndrome
arrhythmia is polymorphic VT (Torsades de Pointes VT)
presenting complaint of congenital long QT syndrome
Primary presenting complaint : Syncope, SCD in children and young adults
triggers of Torsades de pointes VT syncope
Exercise Sudden auditory stimuli Sleep QT prolonging states Medication hypokalaemia
treatment of congenital long QT syndrome
Beta blockers –very effective at reducing SCD
Avoid QT prolonging drugs www.crediblemed.org
Avoidance of triggers
-strenuous swimming
-Breath holding
-Loud sudden noises
Correction of electrolyte abnormalities, maintenance of serum K at upper limit of normal range.
what arrhythmias are ccommon in Brugada Syndrome
Risk of polymorphic VT, VF
Atrial fibrillation common
What does ECG show for Brugada?
ST elevation and RBBB in V1-V3
ECG findings may be intermittent, change over time
what are the associated genes for Brugada?
12 associated genes: Cardiac sodium channel (SCN5A) and calcium channel (CACN1Ac )
what type of genetic inheritance is it?
Autosomal dominant: Adults, 8x males
What are triggers for brugada syndrome?
VF Triggers: -Usually rest or sleep -Fever -Excessive alcohol, -large meals Genotype and family history of SCD does not influence prognosis
Treatment brugada
Avoidance of drugs that may induce Brugada changes on ECG.
Avoidance of excessive alcohol and large meals.
Prompt treatment of fever with anti pyretic medications
ICD if ventricular arrhythmia
Drugs to avoid in Brugada
Anti-arrhythmic drugs (beta blockers may aggravate ECG changes, therefore only under supervision).
Psychotropics
Analgesics
Anaesthetics
What is hypertrophic cardiomyopathy caused by/
mutation in sarcomeric genes
more males/females tend to have dilated cardiomyopathy?
males
what genes are involved in dilated cardiomyopathy?
Sarcomere and desosomal genes, laminA/C and desmin if there is conduction disease, dystrophin if X-linked
what is arrhythmogenic RV cardiomyopathy?
Fibro-fatty replacement of cardiomyocytes.
what genes cause arrhythmic RV cardiomyopathy?
Autosomal dominant mutations in the genes for desmosomal proteins; autosomal recessive mutations in nondesmosomal genes
How is an ICC diagnosed?
Mutation found in 20-60% of ICC
Absence of a mutation does not exclude gene (? Other unknown gene/untested gene).
Often a gene variant found, of unknown significance
Diagnoses relies on combination of clinical and genetic testing: A mutlidisciplinary approach (geneticists and cardiologists)
Lifestyle changes for long QT syndrome?
Diet: potassium rich foods (bananas, beans, oranges, green leafy vegetables, nuts)
Diarrhoea, vomiting
Underwater breath holding.
Avoiding sudden loud noises.
Lifestyle changes for Brugada Syndrome?
Excessive alcohol
Prompt treatment of fevers
medications for long QT syndrome to avoid?
Anti depresants, antibiotics, antihistamines
what is the risk associated with competitive sport?
3X risk of sudden death
why is an S-ICD better than a transverse ICD?
Prevention of vascular complications
Better cosmetic and functional outcome
Lead extraction safe
