Arrhythmias

Question 1

Shockable rhythms

Answer 1

Ventricular tachycardia

Ventricular fibrillation

Question 2

Non-shockable rhythms

Answer 2

Pulseless electrical activity

Asystole

Question 3

Narrow complex tachycardias

Answer 3

Atrial fibrillation

Atrial flutter

Supraventricular tachycardia

Question 4

Broad complex tachycardias

Answer 4

Ventricular tachycardia

SVT with bundle branch block

Question 5

Treatment of stable AF

Answer 5

Rate control with beta blocker or diltiazem

Question 6

Treatment of stable atrial flutter

Answer 6

Rate control with beta blocker

Question 7

Treatment of stable SVT

Answer 7

Vagal maouevres and adenosine

Question 8

Treatment of stable VT

Answer 8

Amiodarone infusion

Question 9

Treatment of stable known SVT with BBB

Answer 9

Treat as normal SVT

Question 10

Atrial flutter

Answer 10

Re-entrant rhythm where electrical signal re-circulates in self-perpetuating loop due to an extra pathway

Question 11

Atrial contraction rate in atrial flutter

Answer 11

300bpm

Question 12

Ventricular contraction rate in atrial flutter

Answer 12

150bpm

Signal makes its way into ventricles every second lap due to long refractory period in AV node

Question 13

Conditions associated with atrial flutter

Answer 13

HTN

IHD

Cardiomyopathy

Thyrotoxicosis

Question 14

Management of atrial flutter

Answer 14

Rate/rhythm control with beta blockers or cardioversion

Treat reversible underlying cause

Radiofrequency ablation of re-entry rhythm

Anticoagulation based on CHA2DS2VASc score

Question 15

SVT

Answer 15

Electrical signal re-entering atria from the ventricles

Once signal is back in the atria it travels back through AV node and causes another ventricular contraction

Question 16

Types of SVT

Answer 16

Atrioventricular nodal re-entrant tachycardia- re-entry point through AV node only

Atrioventricular re-entrant tachycardia- re-entry point is accessory pathway (WPW)

Atrial tachycardia- signal originates in atria somewhere other than sinoatrial node

Question 17

Adenosine action

Answer 17

Slows cardiac conduction through AV node

Resets back to sinus rhythm

Needs to be given as rapid bolus

Question 18

Adenosine contraindications

Answer 18

Asthma

COPD

HF

Heart block

Severe hypotension

Question 19

Adenosine warnings

Answer 19

Causes brief asystole/ bradycardia

Scaring feeling of dying/ impending doom

Question 20

Adenosine dosing

Answer 20

6mg then 12mg then 12mg if no improvement between doses

Question 21

Long term management of paroxysmal SVT

Answer 21

Beta blockers, calcium channel blockers, amiodarone

Radiofrequency ablation

Question 22

Wolf parkinson white syndrome

Answer 22

Extra electrical pathway connect atria and ventricles (often called bundle of Kent)

Question 23

WPW ECG changes

Answer 23

Short PR interval

Wide QRS complex

Delta wave (slurred upstroke on QRS complex)

Question 24

Definitive management of WPW

Answer 24

Radiofrequency ablation

Question 25

Torsades de pointes

Answer 25

Polymorphic ventricular tachycardia Height of the QRS complex progressively gets smaller then larger etc

Question 26

Causes of prolonged QT

Answer 26

Long QT syndrome (inherited) Medications (antipsychotics, citalopram, flecanide, sotalol, amiodarone, macrolides) Electrolyte disturbances (hypokalaemia, hypomagnesaemia, hypocalcaemia)

Question 27

Acute management of torsades de pointes

Answer 27

Correct the cause Magnesium infusions (even if normal serum magnesium) Defibrillation of VT occurs

Question 28

Longterm management of prolonged QT syndrome

Answer 28

Avoid medications that prolong QT interval Correct electrolyte imbalances Beta blockers (not sotalol) Pacemaker or implantable defibrillator

Question 29

Ventricular ectopics

Answer 29

Premature ventricular beats caused by random electrical discharges from outside the atria

Question 30

Bigeminy

Answer 30

Ventricular ectopics are occurring so frequently that they happen after every sinus beat ECG looks like normal sinus beat followed immediately by an ectopic, then normal, then ectopic etc

Question 31

Management of ventricular ecoptics

Answer 31

Check bloods for anaemia, electrolyte disturbances and thyroid abnormalities Reassurance and no treatment if otherwise healthy

Question 32

First degree heart block

Answer 32

Delayed AV conduction Every atrial impulse leads to ventricular contraction

Question 33

Second degree heart block

Answer 33

Some atrial impulses do not make it through AV node Instances where p waves do not lead to QRS complexes

Question 34

Mobitz type 1 (Wenckebach's)

Answer 34

Atrial impulses become gradually weaker until doesn't pass through AV node Increasing PR interval and then drops P wave

Question 35

Mobitz type 2

Answer 35

Intermittent failure or interruption of AV conduction Usually set ratio of p waves to QRS complexes PR interval remains normal Risk of asystole

Question 36

2:1 block

Answer 36

2 p waves for each QRS complex Every second p wave is not strong enough to stimulate a QRS complex

Question 37

Third degree heart block

Answer 37

Complete heart block No observable relationship between p waves and QRS Significant risk of asystole

Question 38

1st line treatment for unstable bradycardias/ AV node blocks

Answer 38

Atropine 500mcg IV

Question 39

Treatment for unstable bradycardias if no improvement

Answer 39

Atropine 500mcg repeated (up to 6 doses) Other inotropes (such as noradrenaline) Transcutaneous cardiac pacing

Question 40

Treatment if patients high risk of asystole (Mobitz 2, complete heart block)

Answer 40

Temporating transvenous cardiac pacing Permanent implantable pacemaker

Question 41

Atropine action

Answer 41

Antimuscarinic medication Inhibits the parasympathetic nervous system

Question 42

Atropine side effects

Answer 42

Pupil dilatation Urinary retention Dry eyes Constipation