cardiac conditions that cause sudden death

Question 1

what is considered a long QT interval usually

Answer 1

>450ms

Question 2

what happens in long QT syndrome

Answer 2

the ventricular repolarizationis prolonged - long QT interval

Question 3

romano ward syndrome

Answer 3

autosomal dominant cuase of long QT syndrome - causes isolated long QT

Question 4

JLN syndrome

Answer 4

autosomal recessive cause of congenital long QT - associated with congenital deafness

Question 5

why does hypokalaemia cause acquired long QT

Answer 5

K leaving the cell si responsible for stages 2 3 and 4 of the AP

if there is less K, prolongs the plateau phase

Question 6

what 2 other electrolyte abnormalities cause acquried long QT

Answer 6

hypoMg

hypoCa

Question 7

which ABx cause long QT

Answer 7

macrolides eg azithromycin

Question 8

what other drugs cause long QT

Answer 8

antidepressants, TCA and citalopram

antipsychotics

Question 9

which class of anti arrhythmic drugs prolonged the plateau phase of the cardiac AP

Answer 9

3 - amiodarone and sotalol

Question 10

what do the LGT genes encode

Answer 10

cardiac potassium and sodium channels

Question 11

what is the genetics cause of long qt

Answer 11

heterogenous - caused by lots of different genes

each different gene causes a disease with a different phenotype

Question 12

what are the particular provocations for LGT 1 2 and 3

Answer 12

1 - strenuous exericse, especially swimming

2 - emotion and loud noises

3 - rest or sleep

Question 13

what can long at lead to and what are the symptoms

Answer 13

torsade de pointes - a polymorphic ventricular tachycardia

syncope and palpitations

Question 14

what is the danger of TdP

Answer 14

it can degenerate into ventricular fibrillation

can terminate spontaneously

Question 15

what is assoicated with increased risk in long qt syndrome

Answer 15

the length of the qt interval

Question 16

what treatment is advised for congenital long qt syndrome

Answer 16

• avoid triggers
• beta blockers (not sotalol)
• permanent pacing
• ICD

Question 17

who is eligible for an ICD with congenital long qt

Answer 17

those resuscitated from cardiac arrest or those with syncope despite beta blocker treatment

Question 18

genes encoding which channels are mutated in short QT syndrome

Answer 18

K channels

Question 19

short QT syndrome presentation

Answer 19

usually seen in young children adn they often dont survive, it is a cause of SIDS

assoicated with AF, ventricular arhythmias and suden death

Question 20

management of short QT syndrome

Answer 20

ICD

Question 21

what is the classical ECG of brugada syndrome

Answer 21

ST elevation, inverted T wave, RBBB in V1-3

Question 22

does someone with brugada syndrome have ecg changes all the time?

Answer 22

no, may be intermittent and change over time

often seen with fever

Question 23

what drugs can be used to provoke ecg changes in brugada syndrome

Answer 23

class 1 anti arrhythmics - flecainide or ajmoline

Question 24

what are some triggers for VF in brugada syndrome

Answer 24

rest, sleep, fever, aalcohol, large meals

Question 25

what drug should be avoided in brugada syndrome

Answer 25

beta blockers

Question 26

what is the management of brugada syndrome

Answer 26

ICD - advised in those who have a cardiac arrest, abnormal ecg or collapse

Question 27

what is the inheritance of CPVT

Answer 27

au dominant

Question 28

what happens in CPVT

Answer 28

catecholamine release in response to activity or stress causes sympathetic stimulation of the heart - leads to an increase in IC calcium ion concentration and results in an arrhythmia cascade

Question 29

mutations in which genes are associated with CPVT

Answer 29

RYR2 or CASQ2

Question 30

what arrhythmia does CPVT cause

Answer 30

bidirectional ventricular tachycardia

Question 31

how does CPVT present

Answer 31

with syncope or sudden death on activity/stress

Question 32

what are the investigations of CPVT like when it is not being provoked

Answer 32

normal at baseline

Question 33

why is management of CPVT hard

Answer 33

a cardiac event or defibrillation cause catecholamine release which trigger the arrhythmia. so does hospital environemnet and stress

Question 34

management of CPVT

Answer 34

beta blockers

fleicainide

ICD

Question 35

what happens in WPW syndrome

Answer 35

there is a congneital anatomical re entrant circuit between the atria and ventricles called the bundle of Kent - this doesnt have a refractory period so allows electrical signals to go back from ventricles to atria really fast

Question 36

what is the risk in WPW linked to

Answer 36

how fast the bundle of kent can transmit signals

Question 37

ecg changes in WPW

Answer 37

delta wave on ecg - slurred upstroke on QRS complex

short PR interval