Sudden Death Flashcards
3 inherited cardiac causes of sudden death?
Inherited arrhythmia syndrome
Inherited cardiomyopathy
Inherited multi system disease with CVS involvement, e.g. myotonic dystrophy
Another name for arrhythmia syndromes?
Channelopathies
6 inherited channelopathies
Congenital LQTS
Brugada syndrome
Catecholaminergic polymorphic VT
Short QT syndrome
Familial AF
WPW
An inherited cardiomyopathy
hypertrophic cardiomyopathy
Screening is routinely offered for which type of cardiomyopathy?
Dilated
Hypertrophic
Arrhythmogenic right ventricular cardiomyopathy
When do early depolarisations occur?
What arrhythmia do they cause?
What Potentiates them?
Phases 2 and 3 of cardiac AP
Torsades de Pointes
Hypokalaemia and Class Ia and III anti-arrhythmatics which prolong QT interval
When do delayed depolarisations occur?
What inherited condition are they seen in?
What arrhythmia do they cause?
phase 4 of cardiac AP
Catecholaminergic polymorphic ventricular tachycardia
Bidirectional VT
Inheritance pattern of cardiac conditions?
AD
Most common inherited cardiac cause of sudden death?
How many people are carriers for the gene?
LQTS
1 in 2000
What arrhythmia is caused by LQTS?
What triggers the arrhythmia’s?
Torsades de Pointes
(polymorphic VT)
Triggered by adrenergic stimulation, e.g. excitement, exercise
What is Romano Ward Syndrome?
Inheritance?
Most common form of LQTS
AD
What LQTS is assoc w deafness?
Inheritance?
Jervell and Lange-Nielsen Syndrome
AR
Pathophysiology behind LQTS?
Reduced ionic current = prolonged repolarisation = QT interval prolongation
How is LQTS diagnosed?
QT>480ms (>0.48s/>2 big boxes and 2 small boxes)
Symptoms of LQTS?
Syncope
Stress
Potentially HX of deafness (JALNS)
5 meds that should be avoided in LQTS?
Clarithromycin Azithromycin Imipramine Amitriptyline Haloperidol
LQTS1 prophylactic advice?
Avoid strenuous exercise
LQTS2 prophylactic advice?
Avoid loud noises
What is affected in SQTS (short QT)?
How long does it have to be for this?
Who’s is affected by SQTS?
K+ channels
<300ms (less than 1 big box and 3 small boxes) at HR <80bpm
Young children
SQTS puts you at risk of what arrhythmia?
TdP (polymorphic VT)
VF
What arrhythmia do people with Brugada syndrome get?
AF
ECG abnormalities in Brugada syndrome?
ST elevation and RBBB affecting V1-V3
Inheritance of Brugada syndrome?
Who gets it?
AD
Young males
Triggers for VF in Brugada Syndrome?
Usually sleep or rest
Fever
Excess alcohol
Large meals
Channels and genes assoc w Brugada syndrome?
Cardiac sodium channel (SNC5A)
Calcium channel (CACN1Ac)
Treatment of Brugada Syndrome?
Avoid triggers
Avoid Na channel blocker/anti-arrhythmatics
Go into hospital if fever
ICD if severe
What is catecholaminergic polymorphic ventricular tachycardia?
Triggers?
adrenergic-induced bidirectional and polymorphic VT and SVT’s
Stress (e.g. alarm clocks, jumping in cold pool), physical activity
ECG in CPVT?
usually normal unless induced arrhythmia, echo also normal
Autosomal dominant CPVT gene?
Autosomal recessive CPVT gene?
Dominant - Ryanodine receptor mutation (RyR2)
Recessive - Cardiac Calsequestrin gene (CASQ2)
Treatment of CPVT?
Prophylaxis?
Defibrillate if necessary
Prophylaxis:
- avoid triggers
- B-blockers
- +/- Flecainide
- +/- ICD
3 ECG features of WPW?
Short PR
Delta waves
Ventricular pre-excitation
Most common arrhythmias in WPW?
AV re-entry tachycardia
AF
Pathophysiology of WPW?
No conduction delay between atria and ventricles due to an accessory pathway bypassing AV node
Treatment for WPW?
Leave it if accessory pathway does not conduct quickly
Otherwise, ablate the pathway
Most common cardiomyopathy?
What type of mutation is most common? What gene is affected most commonly?
Hypertrophic
Sarcomere gene mutation - most common MYBPC3
What % of patients with HOCM die each year?
1%
2 ECG changes that suggest hypertrophy?
Positive deflection in V5
Negative deflection in V2
Treatment of HOCM?
ICD if arrest, sustained VT or high risk e.g. 1st degree FHx, thick wall, recent syncope
If none then leave it as risk of cardiac event <4%
Who gets dilated cardiomyopathy?
adulthood-elderly
Men
Genes and structures related to dilated cardiomyopathy?
Sarcomere and desmosomal genes
Lamina A/C if there is conduction disease
Dystrophin gene if X-linked (muscular dystrophy)
Pathophysiology of arrhythmogenic right ventricular cardiomyopathy (or dysplasia)
Inheritance and genes?
Cardiac myocytes replaced by fibrofatty tissue which cannot conduct
AD - desmosomal proteins
AR - non-desmosomal proteins
ECG features of ARVC?
QRS prolongation