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Flashcards in *Arrhythmias Deck (125)
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1

What is an arrhythmia?

Abnormality of heart rate or rhythm

2

What are the 2 broad anatomical types of arrhythmias?

Supraventricular
Ventricular

3

What are the names of the 3 internal tracts that connect the SA node and AV node?

Anterior, middle and posterior internodal tracts

4

What are ectopic beats?
Name when you have several of these in a row?

Beats or rhythms that originate in places other than the SA node (when the latent pacemaker fires at a rate faster than the SA node)
Ectopic rhythm - ectopic focus dictates the entire rhythm

5

Are ectopic beats/ rhythms dangerous?

Depends how the affect the cardiac output

6

How can arrhythmias be categorised based on rate?

Tachyarrhymias
Bradyarrhytmias

7

What are the 4 types of atrial tachycardia? (SVT)

Atrial fibrillation
Atrial flutter
Ectopic atrial tachycardia
Sinus tachycardia

8

What are the 2 types of atrial bradycardia?

Sinus bradycardia
Sinus pauses

9

What are the 3 types of atrioventricular node arrhythmias?

AV node re-entry
Accessory pathways
AV block

10

What are the 4 types of ventricular arrhythmias??

Premature ventricular complex
Ventricular tachycardia
Ventricular fibrillation
Asystole

11

What are the clinical causes of arrhythmias? (5)

Abnormal anatomy e.g. left ventricular hypertrophy, accessory pathways
Autonomic e.g. sympathetic stimulation (nervousness, hyperthyroidism), increased vagal tone
Metabolic e.g. hypoxic myocardium, ischaemic myocardium, electrolyte imbalances
Inflammation e.g. viral myocarditis]Drugs
Genetics (mutations of cardiac ion channels) e.g. congenital long QT syndrome

12

What are the 5 mechanisms of arrhythmias?

Defects in impulse formation (altered automaticity, triggered activity)
Defects in impulse conduction (re-entry, accessory tracts, conduction block)

13

What is altered automaticity?

When a latent pacemaker takes over the SA nodes function as the normal pacemaker of the heart (causes escape or ectopic beats) - can occur physiologically when the ANS modulates the SA nods activity e.g. caused by drugs, ischaemia

14

What is triggered activity?

When abnormal action potentials are triggered by a preceding action potential resulting in the heart cells beating twice e.g. tornadoes de points

15

What is re-entry?

Self-sustaining electrical circuit stimulates an area of the myocardium to be stimulated repeatedly

16

What is conduction block?

Any disease that disrupts electrical conduction may reduce conduction or cause heart block

17

What are accessory pathways?

Additional electrical conduction pathway between 2 areas of the heart e.g. WPW

18

What effect does hypothermia have on phase 4 of AP slope?

Decreases it (altered automaticity)

19

What effect does hyperthermia have on phase 4 of action potential slope?

Increases it (altered automaticity)

20

What effect do hypoxia and hypercapnia have on phase 4 of AP slope?

increase it (altered automaticity)

21

What effect does hypokalaemia have on phase 4 of AP slope?

Increases it (also prolongs repolarisation and increases ectopics)

22

Symptoms of arrhythmias?

Palpitations (a noticeably rapid, strong or irregular heart beat)
SOB
Diziness
Syncope
Sudden cardiac death
Worsen pre-exisiting conditiosn e.g. angina

23

Investigations of arrhythmias? (&)

12 lead ECG
CXR
Echocardiogram
Stress ECG
24 hours ECG hotter monitoring
Event recorder
Electrophysiological (EP) study

24

Why is an ECG done for arrhythmias?

To assess rhythm
Signs of previous MI, pre-excitation (WPW)

25

What sign on an ECG suggests a previous MI?

Pathological Q waves

26

Why perform an exercise ECG in a patient with suspected arrhythmia?

To assess for ischaemia
Exercise induced arrhythmia

27

Why perform a 24 hour hotter ECG in a patient with suspected arrhythmia?

To assess for paroxysmal arrhythmia
To link symptoms to underlying heart rhythm

28

Why perform an echo in a patient with suspected arrhythmia?

To assess for structural heart disease

29

Why perform an electrophysiological study in a patient with a suspected arrhythmia?

To trigger the arrhythmia and study its mechanism
Opportunity to treat by ablation at the same time

30

What are the symptoms of atrial ectopic beats?

Asymptomatic
palpitations