Sudden Cardiac Death And Catecholaminergic Arrest

Question 1

What is sudden cardiac death

Answer 1

Death within 6 hours of witnessed normal heath due to SCA

Question 2

What is sudden arrhythmic death syndrome

Answer 2

Death from SCA with no cause on PM

Question 3

Name some causes of SCD

Answer 3

Coronary artery disease
Structural - LV hypertrophy, HF, myocarditis
Arrhythmias
Noncardiac -drug OD, PE

Question 4

Describe hypertrophic cardiomyopathy

Answer 4

Asymetrical thickening of the myocardium (particularly AV septum) which can lead to LV outflow obstruction. The myocytes are chaotic and there can be an element of fibrosis

Question 5

What are the results of the hypertrophy seen in HCM

Answer 5

LV outflow obstruction
Risk of VT and VF
Reduced pumping efficiency
Mitral valve abnormalities

Question 6

What are the genetics of HCM

Answer 6

AD mutation in genes encoding sarcomeric proteins eg B-myosin heavy chain and troponin

Question 7

what is your typical HCM patient

Answer 7

Black, male, 20-30 y/o

Syncope, chest pain SOB etc on physical exertion

Question 8

What does an ECG of a HCM patient look like

Answer 8

Non-specific changes
Dagger Q waves (more activity but more muscle to pass through)
ST segment often goes in the opposite direction to QRS
T wave inversion
AF and SVT

Question 9

How is HCM managed

Answer 9

Amiodarone
B blockers
Verapamil
Anticoagulant and catheter ablation for AF
ICD

Question 10

What is ARVC

Answer 10

Arrhythmogenic RV cardiomyopathy

Fibro-fatty replacement of RV myocytes meaning RV free wall is thin

Question 11

What are the genetics of ARVC

Answer 11

AD mutations in desmosomal genes

Question 12

What is the typical ARVC patient

Answer 12

Northern Italy/Greece, teens/20’s, males, during competitive sport
Palpitations and syncope
Eventually get HF

Question 13

What does the ECG of ARVC show

Answer 13

Epsilon waves (blip at the end of QRS)
VT with LBBB or ectopics cause the symptoms
V1-V3 show T inversion, prolonged S wave upstroke, wide QRS

Question 14

How is ARVC managed

Answer 14

Amiodarone and b-blockers
ICD
Radio frequency ablation

Question 15

What is dilated cardiomyopathy

Answer 15

LV enlarges and has contractile dysfunction (reducing ejection fraction) but LV wall thickness is normal
RV may also be involved

Question 16

What are the genetics of dilated cardiomyopathy

Answer 16

AD
Genes encoding sarcomeric or lamin A or C
(Only 30% of cases are genetic - lots of other things cause it)

Question 17

What is a typical dilated cardiomyopathy patient

Answer 17

Black,male, 20-60 y/o

Question 18

How would dilated cardiomyopathy present

Answer 18

Often as congestive HF

AF or stroke as a result

Question 19

What would investigations for dilated cardiomyopathy show

Answer 19

CXR: cardiomegaly and pulmonary oedema
ECG: very non specific sinus tachy, LBBB
Echo: LV dilation, reduced systolic and diastolic function, mitral/tricuspid regurg

Question 20

How is dilated cardiomyopathy managed?

Answer 20

As HF so ACEi, b-blockers, digoxin

Question 21

What is brugada syndrome

Answer 21

Arrythmias (VF or pVT) leading to SCD in the presence of a structurally normal heart

Question 22

What are the genetics of brugada syndrome

Answer 22

AD mutation affecting sodium ion channels

Question 23

What is the typical brugada syndrome presentation

Answer 23

East Asian

Syncopal episodes when high vagal tone, fever or alcohol

Question 24

What are the ECG features of brugada syndrome

Answer 24

Coved ST + inverted T + J point elevation in V1-3

May have prolonged PR

Question 25

How can the ecg changes of brugada be induced

Answer 25

Ajmaline

Question 26

How is brugada syndrome diagnosed?

Answer 26

``` ECG changes + one of: Documented pVT or VF Family history of SCD <45 Family members with coved ST syncope Nocturnal agonal respiration ```

Question 27

How is brugada syndrome managed

Answer 27

ICD + avoidance of flecainide, verapamil, amytiptiline, propranolol, hypokalaemia, fever

Question 28

What is the normal QT interval

Answer 28

<440 males | <460 females

Question 29

What causes the SCD in long QT

Answer 29

Ventricular tachyarrhythmia

Question 30

What is LQTS

Answer 30

Encompasses a range of syndromes all leading to prolonged myocardial repolarisation Also encompasses acquired LQTS

Question 31

What can cause acquired LQTS

Answer 31

Drugs, hypokalaemia/magnasaemia/calcaemia, hypothermia, MI, SAH

Question 32

What are the genetics of LQTS 1-3 and the affect on the ion channels

Answer 32

LQT1 and LQT2: KCNQ1 and KCNH2 (K leaves cell too slowly) | LQT3: SCN5a (Na enters cell too quickly)

Question 33

In which situations would LQT1-3 present themselves

Answer 33

1 - increased adrenergic tone (particular swimming) 2 - startling 3 - resting and bradycardia

Question 34

Describe the T wave ECG features of LQTS 1-3

Answer 34

1 - broad based T 2 - notched T 3 - prolonged ST

Question 35

Describe the generic ECG changes for all LQTS

Answer 35

Prolonged QTc T wave abnormalities (specific to each type) TdP T wave alternans

Question 36

How is the QTc interval calculated?

Answer 36

Bazetts formulae QT/ square root of RR interval (QT is measured from initial wave of QRS to T wave return to baseline

Question 37

How does LQTS present

Answer 37

Young people with syncope | Often have prodrome of palpitations, chest pain and SOB

Question 38

How is LQTS managed?

Answer 38

B blocker ICD Lifestyle changes

Question 39

What is romana ward

Answer 39

The phenotypic classification of LQTS 1-6, 9-12

Question 40

What is Jervell and Lange Nielsen

Answer 40

AR mutation. 2 inherited copies of KCNQ1 (whereas 1 copy = Romano ward)

Question 41

Aside from cardiac features, what else do jervell and Lange Nielsen patients have

Answer 41

Bilateral sensorineural deafness

Question 42

What is Anderson Tawil syndrome

Answer 42

Phenotypic name for LQTS 7

Question 43

Which gene is effected in LQT7 (Anderson Tawil)

Answer 43

KCNJ2

Question 44

How does Anderson Tawil present (ecg and features)

Answer 44

``` Bidirectional VT Low set ears and wide spaced eyes Clinodactyly Syndactyly Short Scoliosis Hypokalaemic periodic paralysis ```

Question 45

What is Timothy syndrome and it’s genetics

Answer 45

Phenotypic name for LQTS8 | CACNA1C

Question 46

What ion channel is affected and what is the implication in Timothy syndrome

Answer 46

Delayed calcium channel closing (so more calcium in) leading to increased intracellular exciteability

Question 47

How does Timothy syndrome present

Answer 47

Syndactyly, congenital heart malformation, autism | In atypical they also have joint issues and AF

Question 48

What is CPVT

Answer 48

Catecholaminergic polymorphic ventricular tachycardia

Question 49

Talk through the genetic mutation and resulting ion channel abnormality that leads to biderectional VT in CPVT

Answer 49

AD mutation of RyR2 = leaky ryandadine receptor channel = Ca leaks out of SR in diastole = afterdepolarisation = bidirectional VT

Question 50

How do adrenergics worsen the situation in CPVT

Answer 50

More Ca in the SR so more to leak out + adrenergics increase the sensitivity of the ryanadine receptor channel

Question 51

What is your typical CPVT patient

Answer 51

Child/adolescent with FH of SCD and person history of “seizures”

Question 52

What ECG features are seen in CPVT

Answer 52

Normal at rest! | Bidirectional VT or VF on exercise or emotional stress

Question 53

What is the immediate management of CPVT

Answer 53

Adrenaline will worsen the VT | Give B blockers

Question 54

What is the long term management of CPVT

Answer 54

ICD B-Blocker Fleccainide, verapamil

Question 55

What is Lev-Lenegres/PCCD, it’s genetic mutation and ion channel involved

Answer 55

Progressive cardiac conduction defect SCN5A Sodium channel affected

Question 56

What are the ECG features of PCCD

Answer 56

Over time they progress to a complete heart block with resulting arrythmias

Question 57

How is PCCD managed

Answer 57

Pacemaker for bradycardia | Anti arrhythmics

Question 58

What is adrenalines affect on a1 receptors

Answer 58

Vasoconstriction Increased aortic diastolic pressure to increase coronary blood flow BUT decreased cerebral perfusion pressure

Question 59

What does adrenaline acting on A2 result in

Answer 59

Platelet activation = damage to cerebral vasculature

Question 60

What does adrenaline acting on B1 result in

Answer 60

Increased inotropy and chonotropy which increases myocardial metabolic demand

Question 61

What were the results of paramedic 2 trial

Answer 61

Adrenaline increased 30 day survival but decreases neurological outcome