Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

module 103 - theme 3 > sudden cardiac death > Flashcards

sudden cardiac death Flashcards

(53 cards)

Start Studying
1
Q

what is sudden death?

A
  • natural, rapid, unexpected
  • not trauma, toxicity or poison
  • not due to chronic illness
  • natural death within one hour of the onset of acute symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the causes of sudden death?

A
  • heart and/or its vessels
  • noncardiac vessels
  • pulmonary system (PE)
  • central nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what causes sudden cardiac death?

A

sudden death due to cardiovascular/coronary vessel causes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the direct causes of sudden cardiac death?

A
  • coronary obstruction: infarct, embolism

- arrhythmia/dysrhythmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the disorders leading to risks for sudden cardiac death?

A
  • CHD/low LVEF
  • structural heart disease
  • primary arrhythmia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the definition of a cardiac arrest?

A

a sudden stop in effective blood circulation due to the failure of the heart to contract effectively or at all

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is an acute myocardial infarction?

A

when blood flow to some heart muscle is impaired. Usually the heart continues pumping but less effectively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the definition of heart failure?

A

when the circulation is substandard, but the heart is still pumping sufficient blood to sustain life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is arrhythmia/dysrhythmia?

A

a variation in the normal beating pattern of rhythm of the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the 3 broad categories of arrhythmia causes?

A
  • electrical
  • structural
  • ischaemic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do the electrical causes link to arrhythmia?

A
  • ion channels and electrical issues at cellular level

- extra conduction pathways at the organ level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how do the structural causes link to arrhythmia?

A
  • unusual shape or size of cardiac tissue that changes signal pathway
  • can lead to signal delays that interfere with cardiac conduction cycle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how do the ischaemic causes link to arrhythmia?

A
  • hypoxia makes local heart tissue electrically unstable

- effectively changes signal pathway, leading to delays that interfere with cardiac conduction cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are the causes of primary arrhythmia?

A
  • unstable myocardium: often due to damaged or hypoxic tissue
  • ion channel pathologies: long QT syndrome
  • accessory conduction pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is cardiomyopathy?

A
  • pathology when heart size, shape or thickness is abnormal
  • this excludes heart disease due to coronary artery disease, hypertension, abnormalities of the heart valves, and heart disease present at the time of birth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the consequences of cardiomyopathy?

A
  • risk of pumping dysfunction or low output heart failure

- conduction abnormalities because the normal pathways or electrical conduction are altered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the 2 types of cardiomyopathy?

A
  • dilated (eccentric)

- hypertrophic (concentric)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is associated with tetralogy of fallot?

A

a developmental defect associated with high risk of sudden death even after surgical correction in childhood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is trigger?

A

brief event required to initiate a period of arrhythmia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is substrate?

A
  • ongoing, underlying tissue instability that increases triggers or allows for maintenance and amplification or dysrhythmia.
  • it can be and electrical or structural defect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is R on T (ECG phenomenon)?

A
  • a type of potential trigger for arrhythmias
  • on the ECG, when a premature QRS complex occurs during the previous T wave
  • the T wave is a ‘vulnerable period’ during depolarisation of ventricular AP, refractory period is ending
  • resulting QRS wave is a premature ventricular contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a pacemaker?

Study These Flashcards
A
  • implanted electronic device that had electrodes that can stimulate the heart
  • consistently applies impulses for each heart beat
23
Q

what is a pacemaker used for?

Study These Flashcards
A

bradyarrhythmias and heart block

24
Q

what is an implantable cardioverter defibrillator?

Study These Flashcards
A
  • implanted electronic device that has electrodes that can stimulate the heart
25
how does an implantable cardioverter defibrillator work?
- applies electrical impulses ONLY when ventricular dysrhythmias detected - protects from fast or uncontrolled rhythms
26
what are the indications for implanting an ICD?
- cardiac arrest due to ventricular fibrillation - symptomatic heart failure with low LVEF - cardiomyopathies - congential - channelopathies
27
how do antiarrhythmic drugs work?
usually affect ion channel activity or sympathetic drive
28
what is reperfusion injury?
tissue damage caused when blood supply returns to the tissue after a period of ischemia or hypoxia
29
what causes reperfusion injury?
the restoration of circulation results in inflammation and oxidative damage
30
what are the preventative treatments for reperfusion injury?
- cooling - immunosuppression - oxygen radical scavengers
31
what are the difference between syncope and seizures?
- can be difficult to differentiate from a patient's description - both may have no symptoms - syncope may be registered by Holter monitor - seizure may be registered by EEG - seizures tend to be associated with stiffness and unusual postures/movements - syncope patients 'crumple' and seizure patients tip over
32
what is vasovagal syncope?
vagal increase and symp decrease leading to vasodilation and low heart rate
33
what is exertional syncope?
- neurocardiogenic origin | - benign
34
what is the index case?
- the initial patient in the population of an epidemiological investigation - the case of the original patient that stimulates investigation of other members of the family
35
what is penetrance?
the proportion of individuals carrying a particular variant (or allele) of a gene (the genotype) that also express an associated trait (the phenotype)
36
what happens with incomplete or reduced penetrance?
- some individuals will not express the trait even though they carry the allele - many channelopathies can vary from patient to patient - an individual disease can have different phenotypes - most phenotypes of polygenic, especially in genes for 'risk'
37
what are the mechanisms of arrhythmia?
- substrate for arrhythmia: structural or electrical - ectopic activity: early after depolarisation, short coupling interval, delayed after depolarisation - re-entry - wave break
38
what are the clinical scenarios with sudden cardiac death?
- ischaemic heart disease - structural heart disease - arrhythmic SCD
39
what are the key characteristics of ischaemic heart disease?
- acute ischaemia - ventricular remodelling - scar formation - myocardial fibrosis - coupling - dilatation - poor function
40
what are the key characteristics of dilatated cardiomyopathy?
- accounts for 10% of SCD - non-ischaemic dilatation of ventricle - causes: idiopathic, viral, alcohol, drugs (chemotherapy), autoimmune
41
what is the pathophysiology of structural heart disease?
- subendocardial myocardial fibrosis - neurohormonal activation - increased sympathetic tone - electrode disturbances - leads to: ectopy, re-entry, VT/VF
42
what are the key characteristics of hypertrophic cardiomyopathy?
- most common cause of SCD in young athletes - autosomal dominant, incomplete penetrance - mutation of cardiac muscle sarcomere genes - >45 mutations identified - most commonly beta-myosin or troponin-T - asymmetrical septal hypertrophy - systolic anterior motion of mitral valve - LV outflow tract obstruction
43
what are the symptoms of hypertrophic cardiomyopathy?
- may be asymptomatic - exertional chest pain/dyspnoea - exteriontal syncope - palpitations - mechanism of SCD unclear
44
what is ARVC?
arrhythmogenic RV cardiomyopathy
45
what happens with ARVC?
- replacement of RV myocardium with fibro-fatty tissue - RV hypertrophy and dilatation - VT/VF due to re-entry around interstitial fibrosis
46
what are the symptoms of ARVC?
- often asymptomatic - exertional syncope of SCD - atrial arrhythmia common - epsilon wave of ECG
47
what are the other structural SCD?
- aortic stenosis - mitral stenosis - mitral valve prolapse - congenital heart disease: anomalous coronary arteries, ebstein's abnormally, complex
48
what are the key characteristics of primary arrhythmia?
- non-ischaemic - structurally normal heart - syndromes include: long QT, wolff-parkinson-white, brugada, primary VT/VF
49
what is Wolff-Parkinson-White?
- accessory pathway from atria to ventricle - atrial arrhythmia - ventricular pre-excitation - VT/VF - often clues on resting ECG
50
what is Brugada?
- channelopathy - most commonly SCN5A - affects fast-type sodium channels - reduces conduction velocities - particularly affects RVOT - prone to VT arising from RVOT
51
how do you treat sudden cardiac death?
- identify at-risk groups - preventative treatment - treat underlying cause - avoid precipitants - anti-arrhythmic medication - implantable defibrillators - family screening where appropriate
52
how do you select the patients for ICD?
- survivors of cardiac arrest (not MI) - VT with haemodynamic compromise - high risk groups: coronary disease, poor LV function +/- large scar, broad QRS complex on ECG - some HCM/long QT/Brugada/ARVC - congenital heart disease
53
what are the indications in HCM?
- survived cardiac arrest - one or more of: VF or spontaneous sustained VT, unexplained syncope, LV wall thickness more than 30mm, spontaneous NSVT, abnormal exercise BP, family history of premature sudden death

module 103 - theme 3 (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions