Chapter 11: Peri-Arrest Arrhythmias

Question 1

If a patient has a tachyarrhythmia with adverse features (unstable and at risk of deterioration), what do you do?

Answer 1

Synchronised Cardioversion

Amiodarone 300mg IV (if not responding) over 10-20 mins then 900mg infusion over 24hr

Question 2

What does a synchronised cardioverter synchronise the shock with?

Answer 2

The r wave

An unsynchronised shock can coincide with the t wave and cause VF

Question 3

How should synchronised cardio version be carried out in Atrial Fib/Atrial flutter respectively?

Answer 3

AF - 120-150J and then increase
Atrial flutter - 70-120J and increase as req.

Use Anteroposterior pad posiitons

Must press shock button and continue pressing until shock has been delivered

Need to reactivate synchronisation switch if giving second shock

Question 4

If a patient has a broad complex tachyarrhythmia with adverse features, what do you do?

Answer 4

Synchronised cardioversion

Question 5

If a patient has a broad complex tachyarrhythmia without adverse features that is regular, what do you do?

Answer 5

May be VT or SVT and a bundle branch block

If VT - amiodarone 300mg IV over 20-60 mins then 900mg over 24hr

If SVT + BBB - as regular narrow complex tachycardia

If unsure if SVT with BBB then treat as - VT

Question 6

If a patient has an irregular broad complex tachycardia and is stable, what could it be and what do you do?

Answer 6

AF with BBB –> treat as for narrow complex tachy

Pre-excited AF –> consider amiodarone

Polymorphic VT

Call for expert help

Question 7

How do you treat torsades du pointes?

Answer 7

Stop drugs that prolong QT
Correct electrolytes - esp. hypokalaemia
Magnesium Sulphate 2g IV over 10 mins

Get expert help!

If adverse features - synchronised cardiovert
If pulseless - defibrillation

Question 8

How are patients with regular narrow complex tachycardias without adverse features treated and what can cause it?

Answer 8

Vagal manoeuvre
Adenosine 6mg –> 12mg –> 18mg
Monitor ECG

Question 9

What adverse features would warrant synchronised cardioversion in tachyarrhythmia?

Answer 9

Shock
Syncope
MI
Heart Failure

Question 10

If a regular narrow complex tachycardia doesn’t respond to adenosine, what should be done?

Answer 10

Control rate with beta blocker- possible atrial flutter

Question 11

If a patient has an irregular narrow complex tachycardia but no adverse features, what should be done?

Answer 11

Rate control - beta blocker or diltiazem (digoxin if HF)

Assess thromboembolic risk and consider anticoagulation

Question 12

What can be given for a regular narrow complex tachy if adenosine is CI or fails to terminate?

Answer 12

Verapamil 2.5-5mg IV over 2 mins

Question 13

If a patient has a very rapid narrow complex tachy to the point a pulse is impalpable what should you do?

Answer 13

Synchonised DC cardiovert

Exception to normal as PEA is non-shockable

Question 14

If a patient has had AF for >48hr what should you do?

Answer 14

Rate control
Anticoagulant prophylaxis for 3wk before cardioversion

Can do echo to rule out atrial thrombi and then cardiovert if req.

Question 15

What should be done in patients with AF >48 hrs with urgent need for cardioversion?

Answer 15

LMW heparin in therapeutic dose or IV bolus unfractionated heparin

Maintain APTT 1.5-2x reference

Continue heparin and start anticoagulation after cardioversion

Question 16

What agents can be used for chemical cardioversion of AF?

Answer 16

Flecainide
Propafenone

CI in heart failure, left ventricular impairment, Ischaemic heart disease or prolonged QT

Use amiodarone 300mg 20-60min then 900mg over 24hr here

Question 17

What can cause bradyarrhythmia?

Answer 17

Physiological - athletes, during sleep

Cardiac - heart block, sinus node disease

Non-cardiac - vasovagal, hypothermia, hypothyroid, hyperkalaemia, hypocalcaemia

Drug - Beta blocker, diltiazem, digoxin, amiodarone

Question 18

If a patient with bradyarrhythmia has adverse features, what is the management?

Answer 18

Atropine 500mcg IV –> repeat upto total 3mg dose (6 doses)

Question 19

If atropine doesn’t resolve a bradyarrhythmia with adverse features, what can be done?

Answer 19

Transcutaneous pacing OR

Isoprenaline 5mcg/min IV
Adrenaline 2-10mcg/min IV
Alternative drugs

Question 20

What alternative drugs can be considered for bradyarrhythmia?

Answer 20

Aminophylline 100-200mg slow IV infusion - due to acute inferior MI, spinal cord injury or cardiac transplant

Dopamine - 2.5-10mcg/min

Glucagon - if caused by beta blocker or Ca2+ blocker

Glycopyrrolate - instead of atropine

Digoxin specific antibody - if due to digoxin toxicity

Question 21

What should be done if a patient with bradyarrhythmia is displaying no adverse features?

Answer 21

Assess for risk of asystole:

• Recent asystole
• Mobitz II
• Complete heart block with broad QRS
• Ventricular pause >3s

If risk - Atropine/transcutaneous pacing/adrenaline
If not - continue observations

Question 22

When should you not give atropine

Answer 22

Cardiac transplants - hearts denervated so don’t respond to vagal blockade.

May lead to paradoxical sinus arrest or high grade AV block

Question 23

When is transcutaneous pacing used for bradycardia?

Answer 23

No response to Atropine or CI

Not due to beta blocker/ca2+ blocker - glucagon
Not due to digoxin - digoxin antibody

Should be initiated immediately if indicated

Question 24

When is temporary transvenous pacing considered?

Answer 24

Documented recent asystole
Mobitz type II
Complete AV block

Question 25

What bradycardic heart rate is at risk of making the patient unstable

Answer 25

<40 BPM

Question 26

What tachycardia heart rate is at risk at making the patient unstable

Answer 26

> 150BPM

Question 27

How to initially approach adult tachycardia

Answer 27

Tachycardic - ECG (if unstable) - 3 synchronised shocks then if that doesnt work then give amiodarone loading dose and anohter shock

Tachycardic - ECG (stable) - is it broad or narrow

Broad -
-Regular VT or SVT with BBB (treat as narrow complex tachycardia)
-Irregular - irregular - AF with BBB (treat as narrow and irregular tachy) or polymorphic VT (Mg sulphate)

Narrow -
-Regular (SVT) - Vagal manouvures - then adenosine 6-12-18
-Irregular - AF - BB - digoxin and anticoagulation >48hrs

Question 28

How to initially approach bradycardia

Answer 28

Unstable - atropoine up to 6 times - if doesnt work give atropine 6 times again/adrenaline/transcutaenous pacing - if doesnt work give transvenous pacing

If not unstable check for risk of - recent asystole, type 2 HB, type 3 HB, ventricular pause >3 seconds