Broad complex tachycardia

Question 1

What are broad complex tachycardias also known as?

Answer 1

Ventricular tachycardia / arrythmias

Question 2

What are the two causes of ‘irregular’ broad complex tachycardia?

Answer 2

1. Polymorphic VT - Torsade des pointes

2. Atrial fibrillation with bundle branch block

Question 3

What are the two causes of ‘regular’ broad complex tachycardia?

Answer 3

1. Ventricular tachycardia
2. SVT with rate related BBB (aberrant conduction)
   conduction rate exceeds refractory period and SVT conducts to the ventricles aberrantly.

Question 4

How is ‘regular’ broad complex tachycardia treated?

Answer 4

1. Treated as Ventricular tachycardia
   - unless patient has documented previous ECG with BBB of unchanged morphology
2. If definite SVT with BBB treat as a narrow complex tachycardia

– Amiadorone –

Question 5

Why do ventricular tachycardias require urgent treatment?

Answer 5

Has potential to percipitate ventricular fibrillation and hence requires urgent treatment

Question 6

What is the most common cause of monomorphic VT?

Answer 6

Myocardial infarction

Question 7

When is immediate cardioversion indicated?

Answer 7

If patient has adverse signs such as
(systolic BP < 90, chest pain , heart failure )

–> immediate cardioversion is indicated
/not/ the use of anti arrythmics

Question 8

Out-line the treatment for regular broad complex tachycardias?

Answer 8

1. check for adverse signs (if present - immediate cardioversion)
2. use anti arrythmics ie. amiadorone via a central line
   ( if fail )
3. electrical cardioversion w synchronised DC shock

Question 9

Which drug should definetly not be used in VT?

Answer 9

Verapamil

Question 10

Which two drugs can be used in VT management?

Answer 10

1. Lidocaine

2. Amiodorone

Question 11

In which cases should Lidocaine be used with caution?

Answer 11

Use with caution in severe left ventricle impairment