Broad complex tacchycardias (Complex)

Question 1

What are the 3 main types of broad complex tacchycardias?

Answer 1

Ventricular fibrilation

Ventricular tacchycardia

Torsades de Pointes

Question 2

How does ventricular fibrilation appear on an ECG?

Answer 2

QRS complexes have the following features:

Polymorphic

Irregular

Question 3

What is the management plan for patient with ventricular fibrilation?

Answer 3

1) Basic life support:
DR ABC

2) Defibrillation with unsynchronised cardioversion using 200 J biphasic shock

3) Resume CPR compressions

4) 1mg Adrenaline + 300mg Amiodarone after 3rd shock

5) Administer adrenaline every 3-5 minutes ( or every other alternate shock)

Question 4

What medication shoulds be given after 3rd defibillator shock in patients with ventricular fibrilation?

Answer 4

1mg adrenaline

300mg amiodarone

Question 5

What are the main ECG features of ventricular tacchycardia?

Answer 5

Tacchycardia

No P-waves

Following QRS features:
* Broad complex
* Monomorphic

Question 6

What is the management plan for patient with pulseless ventricular tacchycardia?

Answer 6

1) Basic life support: DR ABC

2) 200 J bi-phasic (unsynchronised) shock

3) Resume CPR and re-check rhythm after 2 minutes

4) IV adrenaline 1mg and 300mg amiodarone after 3 shocks

5) Adrenaline every 3-5 minutes

Question 7

What is the management plan for patient with ventricular tacchycardia who has a pulse?

Answer 7

If haemodynamically unstable:

1) Administer DC shocks

2) Seek epxert help and admnister 300 mg amiodarone IV over 10-20 minutes followed by 900 mg over 24 hours.

If haemodynamically stable and no adverse effects:

IV Amiodarone 300 mg over 20-60 minutes followed by 900 mg over 24 hours.

Question 8

What options should be considered if drug therapy fails in management of VT?

Answer 8

Electrophysiological study (EPS)

Implant able cardioverter-defibrillator (ICD) - particularly indicated in patients with significantly impaired LV function

Question 9

What is the difference between DC shock and defibrillation?

Answer 9

Defibrillation is unsynchronised cardioversion (typically using 200 J bi-phasic shocks)

DC shock is a type of synchronised cardioversion that is delivered in a specific part of the cardiac cycles

Question 10

How does management of VF differ to VT?

Answer 10

If pulseless, VF and VT management is similar however VT requires checking of rhythm after 2 minutes of compressions post shock.

If unstable patient with VT and a pulse, they require synchronised DC shocks vs VF which is always unsynchronised and IV amiodarone 900mg over 24 hours.

Question 11

What is Torsades de pointes?

Answer 11

Form of polymorphic ventricular tachycardia caused by QT prolongation.

Question 12

What are the main features of Torsades de pointes?

Answer 12

Polymorphic QRS complexes that twist around the isoelectric line.

VF can sometimes look like Torasades but the isoelectric line would move up and down as well vs torsades

Question 13

What are the main causes of Torsades de Pointes?

Answer 13

Congenital Long QT syndromes

Medication (e.g. Erythromycin, Tricyclics, Antipsychotics, ketoconazole)

Myocardial infarction

Renal/liver failure

Hypothyroidism

AV block

Toxins

Question 14

What is the management plan for patient with Torsades de Pointes who is haemodynamically unstable?

Answer 14

A Synchronised DC shock followed by IV amiodarone

Question 15

What is the management plan for patient with Torsades de Pointes who is haemodynamically stable

Answer 15

Medicine:
IV magnesium sulphate (2 g over 10 minutes)

Isoprenaline infusion: Consider in patients with reccurent episodes and irresponsive to magnesium sulphate.

Conservative:

Stop offending drugs

Correct electrolyte abnormalities

Surgical/Invasive:

Permament cardiac pacing: Considered in patients with reccurent episodes and irresponsiveness to magnesium sulphate.