ECG Interpretation and Cardiac Arrhythmias Flashcards Preview

CLASP - Sudden Death > ECG Interpretation and Cardiac Arrhythmias > Flashcards

Flashcards in ECG Interpretation and Cardiac Arrhythmias Deck (32)
1

What inherited cardiac conditions are most likely to cause sudden death?

Inherited channelopathies/ arrhythmias
Inherited cardiomyopathies (structural problem)
Inherited Multi-System Disease causing cardiac involvement (e.g. Myotonic dystrophy)

2

Most patients are entirely fit and healthy until an event which causes sudden death. TRUE/FALSE?

TRUE
- many patients never become symptomatic

3

Why does Long QT syndrome (and otherr channelopathies) put patients at a higher risk of sudden death?

- Ventricular repolarisation takes longer than normal
- Early after-depolarisations or ectopic beats at vulnerable points of the cardiac cycle can cause Torsades de Pointes
- This cardiac rhythm is very inefficient and cannot be sustained, resulting in sudden death

4

Give an example of a QT prolonging drug and why these can potentially cause harm?

- Clarithromycin
- If given to patient with an ALREADY undiagnosed prolonged QT syndrome, this drug puts them at a much higher risk of sudden death

5

What other channelopathies can put patients at a higher risk of sudden death and how are these identified?

Brugada syndrome - ST elevation and RBBB in V1-3

Short QT - usually diagnosed in young children who often experience sudden death in childhood

Catecholamine Polymorphic Ventricular Tachycradia (CPVT) - arrhythmias triggered by adrenergic stimulation => patient goes into VT

6

What triggers patients with congenital long QT syndrome to go into Torsades de Pointes?

- Adrenergic stimulation

7

What is the mainstay of treatment for most patients with prolonged QT syndrome?

Beta blockers
- some may have an ICD but this is more common in other conditions as risk of sudden death is lower in Long QT

8

Is Prolonged QT syndrome autosomal dominant or recessive?

Isolated Long QT = Dominant

Long QT and Deafness = Recessive

9

How is a diagnosis of Long QT made?

- usually by specialists in an MDT meeting
- QT interval of >480ms on repeated ECGs = suggestive
- If risk score calculated and >3, this is also suggestive

10

What ECG differences are present in the different variations of Prolonged QT syndrome?

LQTS1 - Large and wide T wave

LQTS2 - Notch in middle of T wave

LQTS 3 - Very delayed T wave

11

What advice should be given to both doctors and patients when managing those who have been diagnosed with prolonged QT syndrome?

- Avoid QT prolonging drugs
- Correct electrolyte disturbances (e.g. during vomiting/diarrhoea)
- Avoid strenuous exertion in LQTS1 - e.g. swimming
- Avoid very loud noises in LQTS2

12

What ECG changes occur in Brugada Syndrome, and when are these more likely to appear?

- ST elevation and Right Bundle Branch Block in leads V1-3
- These signs are intermittent on ECGs
- Occurs more frequently when patient is feverish

Other factors which may increase risk are:
=> when resting/sleeping
=> Alcohol/large meals

13

Patients with family members who have experienced sudden death due to brugada syndrome are therefore at increased risk of sudden death themselves. TRUE/FALSE?

FALSE
- this does NOT increase a patients risk

14

What treatment could potentially be lifesaving in Brugada syndrome?

paracetamol - to reduce fever

15

What drugs should be avoided in Brugada syndrome?

- antiarrhythmics
- analgesics
- psychotropics

16

What triggers Catecholamine Polymorphic Ventricular Tachycardia syndrome (CPVT)?

- emotional tress
- physical activity

17

What is the characteristic ECG finding in CPVT?

Bidirectional VT => some QRS complexes go upwards and some go downwards

18

How is CPVT treated?

- controlled by Beta Blockers
- ICDs usually also in place
- rarely treated with flecainide

19

Describe how unwanted arrhythmias can be produced in Wolff-Parkinson White syndrome?

- accessory pathway stops conduction delay in AV node
=> arrhythmias in the atria (Which would usually cease at the AV Node) can be passed to the ventricles

20

What abnormal finding is found on an ECG of Wolff-Parkinson White?

Delta Wave

21

How is Wolff-Parkinson White Syndrome treated?

Cardiac ablation

22

What problems does hypertrophic cardiomyopathy cause?

- rhythm problems related to large muscle bulk
- Also obstruction may occur

23

HOw does hypertrophic cardiomyopathy usually present?

- sudden death
- heart failure (this may be end stage)

24

What should patients with hypertrophic cardiomyopathy avoid?

- competitive sport
- ICD implantation may be required depending on risk

25

Describe the problem in dilated cardiomyopathy

Problem within the proteins holding the cardiac myocytes together
=> the heart dilates and pulls apart
=> heart muscle cant pump well
=> this leads to rhythm problems

26

Describe what rhythm problem occurs in Arrhythmogenic RV Cardiomyopathy

Ventricular tachycardia which goes continually around the right ventricle

27

How is ARVC managed?

- ICD given to high risk patients
- Avoidance of competitive sport recommended

28

Where in the heart are ICDs placed?

- 1 wire in the RA
- 1 wire in the RV
(device usually sits under left clavicle)

NEW devices can be inserted s/c on the breast bone

29

What complications can arise from an ICD placement?

- infection
- clots (can break off and cause stroke or PE)
- haemothorax
- Pneumothorax

**ALSO high risk of death during ICD extraction**

30

HOw long should the QT interval roughly be on an ECG?

QT interval should complete before the halfway point between two QRS complexes

31

What condition can cause inverted T waves?

hypertrophic cardiomyopathy OR other structural abnormalities

32

What Extra wave is seen on the ECG of Arrhythmogenic RV cardiomyopathy?

Epsilon wave
- "blip" straight after QRS complex