Inherited cardiac conditions

Question 1

What causes ICCs?

Answer 1

misprints in the blue print of the DNA

Question 2

What are the two main types of ICCs?

Answer 2

Channelopathies

Cardiomyopathies

Question 3

Name some channelopathies?

Answer 3

Congenital Long QT syndrome 
Brugada Syndrome 
Catecholaminergic Polymorphic Ventricular tachycardia (CPVT)
Short QT syndrome
Progressive familial conduction disease
Familial AF 
Familial WPW

Question 4

What are the characteristics of channelopathies?

Answer 4

Mutations in genes that encode for cardiac ion channels, so abnormal cardiac cellular electrophysiology, mainly affecting repolarisation
Normal cardiac structure and function
At risk to develop atrial fibrillation in young people and arrhythmias in atria and ventricles

Question 5

Describe Long QT syndrome?

Answer 5

Polymorphic VT (Torsades de pointes) triggered by adrenergic stimulation
Young patients
most commonnly: potassium voltage gated channel member 1 mutation
Triggers (when the arrhythmias arise): exercise, sudden sound, deep sleep or medication – hypokalaemia

Question 6

What is the treatment for Long QT Syndrome?

Answer 6

avoid QT prolonging drugs
avoid triggers (strenuous swimming, breath holding, loud sudden noises)
correction of electrolyte abnormalities

Question 7

Describe Brugada syndrome?

Answer 7

Risk of polymorphic VT, VF
Atrial fibrillation common
Mutation of Cardiac sodium channel (SCN5A) and calcium channel (CACN1Ac )

Question 8

Describe the treatment of Brugada syndrome?

Answer 8

avoidance of triggers (strenuous swimming, breath holding, loud sudden noises)
ICD if they have an arrhythmia
avoid specific drugs i.e. anti-arrhythmic, analgesics

Question 9

Name the 3 common cardiomyopathies?

Answer 9

Hypertrophic cardiomyopathy
Arrhythmogenic Right Ventricular cardiomyopathy (ARVC)
Dilated cardiomyopathy

Question 10

What is the mutation in hypertrophic cardiomyopathy?

Answer 10

in the sarcomeric genes

Question 11

What is the clinical presentation in Hypertrophic Cardiomyopathy?

Answer 11

angina, heart failure, sudden death, atrial fibrillation

Question 12

Where are the mutations in Arrhythmogenic Right Ventricular cardiomyopathy?

Answer 12

Autosomal dominant mutations in the genes for desmosomal proteins; autosomal recessive mutations in nondesmosomal genes
Rarer than hypertropic

Question 13

What are the mutated genes in Dilated cardiomyopathy?

Answer 13

Sarcomere and desosomal genes

laminA/C and desmin if there is conduction disease, dystrophin if X-linked

Question 14

What increases risk of sudden cardiac death in Arrhythmogenic right ventricular cardiomyopathy?

Answer 14

Family history of premature SCD
Severity of RV and LV function
Frequent non-sustained VT
ECG: QRS prolongation
VT induction on EPS
Male gender
Age of presentation