Inherited Cardiac Conditions

Question 1

the types of different inherited cardiac conditions

Answer 1

cardiomyopathy
channelopathy
aortopathy

Question 2

describe cardiomyoathy

Answer 2

heart muscle abnormality

Question 3

describe channelopathy

Answer 3

heart rhythm abnormality;
mutation in genes that encode the cardiac ion channels
abnormal cardiac cellular electrophysiology
mainly affects repolarisation
abnormalities on ECG
normal cardiac structure and function
propensity to develop arrhythmia both atrial and ventricular
!AF in young people!

Question 4

describe aortopathy

Answer 4

arterial blood vessel abnormality

Question 5

symptoms of inherited cardiac conditions - cardiomyopathy

Answer 5

normal appearance, no features of the disease 
breathlessness
swollen legs 
weakness
sudden death

Question 6

symptoms of inherited caridac conditions - channelopathy

Answer 6

normal appearance, no features of the disease
palpitations
fast heart beats
faints
breathlessness
chest pain 
sudden death

Question 7

examples of cardiomyopathies

Answer 7

arrhythmogenic rihgt ventricular cardiomyopathy (ARVV)
hypertrophic cardiomyopathy
dilated cardiomyopathy

Question 8

examples of channelopathies

Answer 8

long QT syndrome
Brugada syndrome 
catecholaminergic polymorphic ventricular tachycardia (CPVT)
short QT syndrome 
progressive familial conduction disease
familial AF
familial WPW

Question 9

examples of aortopathy

Answer 9

Marfan’s syndrome

Ehlos Danlos

Question 10

describe different types of congenital long QT syndrome (cLQTS)

Answer 10

uncommon
autosomal dominant - isolated LQT: romano-ward syndrome
autosomal recessive - associated with deafness: Jervell and Lange-Nielson syndrome

Question 11

symptoms of cLQTS

Answer 11

syncope
triggers of syncope include;
exercise
sudden auditory stimuli
sleep
QT prolonging states - medication, hypokalaemia

Question 12

signs of cLQTS

Answer 12

polymorphic ventricular tachycardia (Torsades de Pointes)

other associated arrythmias - lone atrial fibrillation, heart block

Question 13

pathophysiology of cLQTS

Answer 13

mutation in ion channel
reduced or dysfunctional ionic current (increased Na+ and Ca2+ influx)
prolonged cardiac repolarisation (increased K+ efflux)
QT interval prolongation
triggers polymorphic ventricular tachycardia

Question 14

describe the different LQTS ECG patterns

Answer 14

PP
LQTS1 - wide-based, slowly generated T wave (K current, decreased functional effect)
LQTS2 - wide-based, double hump T wave (K current, decreased functional effect)
LQTS3 - low amplitude deflection on descending limb of T wave (Na current, increased functional effect)

Question 15

treatment of LQTS

Answer 15

beta-blockers
avoid QT prolonging drugs
avoid triggers
correction of electrolyte abnormalities - maintenance of serum K at upper limit of normal range

Question 16

describe Brugada syndrome

Answer 16

autosomal dominant
mutation in cardiac sodium channels and calcium channels
risk of polymorphic ventricular tachycardia and ventricular fibrillation
atrial fibrillation is common
ST elevation and right bundle branch block in V1-V3
ECG findings may be intermittent, change over time (changes may only be seen with provocative testing with flecainide or ajmaline - drugs blocking the cardiac-sodium channel)

Question 17

triggers of Brugada syndrome

Answer 17

ventricular fibrillation triggers;
sleep or rest
fever
excessive alcohol, large meals

Question 18

treatment of Brugada syndrome

Answer 18

avoidance of drugs that may induce Brugada changes on ECG - anti-arrhythmic drugs, psychotropics, analgesics, anaesthetics
avoidance of triggers
prompt treatment of fever with anti pyretic medications
ICD if ventricular arrhythmia

Question 19

describe hypertrophic cardiomyopathy

Answer 19

mutation in sarcomeric genes

1% cardiovascular mortality/year in unselected patients

Question 20

signs of hypertrophic cardiomyopathy

Answer 20

asymptomatic 
atrial fibrillation 
angina 
heart failure 
sudden death

Question 21

describe dilated cardiomyopathy

Answer 21

uncommon, more common in males

mutation in sarcomere and desosomal genes, IaminA/C and desmin if thee is conduction disease, dystrophin if X-linked

Question 22

describe arrhythmogenic right ventricular cardiomyopathy

Answer 22

fibro-fatty replacement of caridomyocytes
LV involvement in >50% of cases
autosomal dominant mutations in the genes for desmosomal proteins; autosomal recessive mutations in nondesmosomal genes
uncommon

Question 23

describe pre-symptomatic identification of individuals at risk of sudden cardiac death (SCD)

Answer 23

SCD may be only the presentation
young age group at risk
effective therapies are available - life style changes, beta-blockers, ICDs
family members may also be at risk

Question 24

describe triggers in long QT syndrome

Answer 24

lifestyle;
diet - potassium rich food (banana, beans, oranges, green leafy vegetable, nuts)
diarrhoea
vomiting 
underwater breath holding 
avoiding sudden loud noises

medications;
anti-depressants
antibiotics
antihistamine

Question 25

describe lifestyle triggers in Brugada syndrome

Answer 25

excessive alcohol

prompt treatment of fevers

Question 26

describe subcutaneous implantable cardiac defibrillator

Answer 26

prevention of vascular complications
better cosmetic and functional outcome
lead extraction safe

Question 27

describe transvenous implantable cardiac defibrillator

Answer 27

high risk of vascular cardiac complications in life and time of patient
cosmetic and functional issues related to ICD position - seat belts, shoulder bags, ports
lead extraction has high risk of mortality and morbidity

Question 28

describe cascade screening

Answer 28

produces a greater rate of case identification than general population screening
once a diagnosis is confirmed in an individual, testing is extended to first degree, and second degree relatives
if relative test positive, their first and second degree relatives are approached and offered testing and so on