Arrhythmias

Question 1

What are the two classes of arrhythmias described by where the arrhythmia arises?

Answer 1

Supraventricular
Ventricular

Question 2

Supraventricular arrhythmias tend to have narrow QRS complexes. True/False?

Answer 2

True
Because the arrhythmia does not originate from ventricles

Question 3

The AV node is the only point of electrical contact between the atria and ventricles. What may additionally be present to cause pathological conduction?

Answer 3

Fibrous ring

Question 4

What are ectopic beats?

Answer 4

Beats/rhythms that originate outwith the SA node

Question 5

Ectopic beats may not be dangerous. True/False?

Answer 5

True

Question 6

Why might ectopic beats not be harmful?

Answer 6

Depends on where they originate - if in non-contractile areas, they are unlikely to affect cardiac output

Question 7

Name the main supraventricular arrhythmias

Answer 7

SVTs: atrial fibrillation, atrial flutter, ectopic atrial tachycardia
Bradycardias: sinus bradycardia, sinus pauses

Question 8

Name the main AV node arrhythmias

Answer 8

AV node reentry
Accessory pathway
AV block (1st, 2nd, 3rd degree)

Question 9

Name the main ventricular arrhythmias

Answer 9

Premature ventricular complex
Ventricular tachycardia
Ventricular fibrillation
Asystole

Question 10

What are the 3 main physiological types of arrhythmia?

Answer 10

Altered automaticity
Triggered activity
Reentry (accessory pathway)

Question 11

How would acute SVT be managed?

Answer 11

Vagal manoeuvres, carotid massage
IV adenosine
IV verapamil(calcium channelblocker)

Question 12

Give examples of some vagal manoeuvres

Answer 12

Holding your breath and bearing down (Valsalva)
Immersing face in ice-cold water (diving reflex)
Holding nose/unblocking ears

Question 13

What is the treatment of choice for managing chronic arrhythmias?

Answer 13

Radiofrequency ablation

Question 14

What is radiofrequency ablation?

Answer 14

Selective cauterisation of cardiac tissue to prevent tachycardia
Target reentry circuit or automatic myocite

Question 15

Which drugs must be stopped before radiofrequency ablation?

Answer 15

Antiarrhythmic drugs 3-5 days beforehand

Question 16

What is notorious for causing AV block in young people?

Answer 16

Cytomegalovirus

Question 17

Describe 1st degree AV block

Answer 17

PR interval increased (greater than 0.2s)

Question 18

Describe 2nd degree Mobitz 1 AV block

Answer 18

PR interval gets progressively longer, followed by dropped QRS

Question 19

Describe 2nd degree Mobitz 2 AV block

Answer 19

Lonely P waves not followed by QRS
N.B. PR interval not prolonged

Question 20

Describe 3rd degree AV block

Answer 20

P waves without QRS complexes
i.e. no association between atrial and ventricular systole

Question 21

What is typical of an ECG showing ventricular tachycardia?

Answer 21

Broad QRS complexes

Question 22

What is the difference between monomorphic and polymorphic VT?

Answer 22

In monomorphic VT, the QRS complexes look similar

Question 23

How would acute VT be treated?

Answer 23

DC cardioversion if unstable
Amiodarone if stable

Question 24

What are the 3 classifications of AF?

Answer 24

Paroxysmal
Persistent
Permanent

Question 25

Define paroxysmal AF

Answer 25

Recurrent AF, lasting less than 48 hours

Question 26

Define persistent AF

Answer 26

AF lasting greater than 48 hours which can be cardioverted to normal sinus rhythm

Question 27

Define permanent AF

Answer 27

AF that is unable to be restored to normal sinus rhythm via pharma + non pharmacological methods

Question 28

What is meant by lone AF?

Answer 28

AF where a cause cannot be found

Question 29

What would a typical ECG of AF show?

Answer 29

Rate greater than 300bpm Irregularly irregular P waves absent

Question 30

What are the two management pathways for AF patients?

Answer 30

Rhythm control (get back to NSR) Rate control (accept AF, control ventricular rate)

Question 31

What pharmacological therapy can be used for rate control in AF?

Answer 31

B blockers Digoxin Calcium channel blocker- Verapamil, diltiazem

Question 32

How can NSR be restored in AF (rhythm control)?

Answer 32

Amiodarone or Flecanide DC cardioversion

Question 33

Class I anti-arrhythmic drugs act on which phase of the AP and block which channels?

Answer 33

Act on phase 0 Block Na+ channels

Question 34

Name a class I anti-arrhythmic drug

Answer 34

Flecainide Lignocaine

Question 35

Class II anti-arrhythmic drugs act on which phase of the AP and block which channels?

Answer 35

Act on phase 4 Block B receptors (B blockers)

Question 36

Class III anti-arrhythmic drugs act on which phase of the AP and block which channels?

Answer 36

Phase 3 Block K channels

Question 37

Name a class III anti-arrhythmic drug

Answer 37

Amiodarone Sotalol

Question 38

Class IV anti-arrhythmic drugs act on which phase of the AP and block which channels?

Answer 38

Phase 2 Block Ca channels

Question 39

What would a typical ECG of atrial flutter look like?

Answer 39

Saw tooth baseline-'Fwaves' Regular rhythm

Question 40

What is Wolff-Parkinson White Syndrome?

Answer 40

There is an extra electrical pathway connecting the atria and ventricles- the Bundle of Kent.

Question 41

What is the treatment for Wolff-Parkinson White Syndrome?

Answer 41

Radiofrequency ablation of the accessory pathway.

Question 42

ECG changes in Wolff-Parkinson White Syndrome?

Answer 42

Short PR interval (< 0.12 seconds) Wide QRS complex (> 0.12 seconds) “Delta wave” which is a slurred upstroke on the QRS complex

Question 43

What is Brugada Syndrome and what are the ECG changes?

Answer 43

Inheritable condition causing an arrhythmia, linked to cases of sudden death. ST elevation and RBBB in V1-V3

Question 44

What is long QT syndrome?

Answer 44

Describes an ECG where the ventricular repolarization (QT interval) is greatly prolonged- can progresses to sudden death

Question 45

Treatment for torsades de pointes

Answer 45

- Magnesium infusion - Defibrillation if VT occurs

Question 46

Long term treatment of congenital QT?

Answer 46

B- blockers Pacemaker