Supraventricular Tachycardia

Question 1

What is supraventricular tachycardia due to?

Answer 1

• Electrical signal re-entering the atria from the ventricles
• Once the signal is back in the atria it travels back through the AV node and causes another ventricular contraction

Question 2

What does supraventricular tachycardia result in?

Answer 2

Narrow complex tachycardia

Question 3

How many types of supraventricular tachycardia are there?

Answer 3

Three

Question 4

What are the three main types of supraventricular tachycardia?

Answer 4

Atrioventricular nodal re-entrant tachycardia (AVNRT)

Atrioventricular re-entrant tachycardia (AVRT)

Atrial tachycardia

Question 5

What is Atrioventricular nodal re-entrant tachycardia (AVNRT)?

Answer 5

when the re-entry point is back through the AV node.

Question 6

What is Atrioventricular re-entrant tachycardia (AVRT)?

Answer 6

When the re-entry point is an accessory pathway

Question 7

What is atrial tachycardia?

Answer 7

Electrical signal originates in the atria somewhere other than the sinoatrial node.

Question 8

How would you diagnose supraventricular tachycardia?

Answer 8

ECG

Question 9

What would you see on an ECG of someone with supraventricular tachycardia?

Answer 9

QRS complex followed immediately by a T wave, QRS complex, T wave

Question 10

How long would the QRS complex be in someone with supraventricular tachycardia?

Answer 10

< 0.12

Question 11

What is the first step in the management of supraventricular tachycardia?

Answer 11

Valsalva Manoeuvre

Question 12

What is the Valsalva manoeuvre?

Answer 12

Trying to blow against resistance- into an empty plastic syringe

Question 13

What is the next step in the management of supraventricular tachycardia if the Valsalva manoeuvre fails?

Answer 13

Carotid sinus massage

Question 14

What is the next step in the management of supraventricular tachycardia if carotid sinus massage fails?

Answer 14

intravenous adenosine

Question 15

How does IV adenosine work?

Answer 15

Slows conduction through the AV node

Question 16

What is the initial dose of adenosine given for supraventricular tachycardia?

Answer 16

Rapid IV bolus of 6mg

Question 17

How is the dose of adenosine increased if 6mg isn’t adequate?

Answer 17

if unsuccessful give 12 mg
→ if unsuccessful give further 12 mg

Question 18

In whom is adenosine contraindicated?

Answer 18

Asthmatics

Question 19

What medication would you use as an alternative to adenosine in asthmatics?

Answer 19

Verapamil

Question 20

What should you warn patients about before injecting adenosine?

Answer 20

The scary feeling of dying / impending doom when injected

Question 21

What is a last resort treatment for supraventricular tachycardia if the other treatments fail?

Answer 21

Direct current cardioversion

Question 22

What are used in the long-term management as prophylaxis against supraventricular tachycardia recurring?

Answer 22

• beta-blockers
• radio-frequency ablation

Question 23

Why should the patient constantly be monitored on an ECG?

Answer 23

To check that the treatments have worked

Question 24

Described in question

Answer 24

Narrow complex tachycardia with left heart strain.
No ST segment elevation or T wave depression.

Question 25

Which patients should be administered DC cardioversion immediately?

Answer 25

HISS
Heart failure
Ischaemia
Shock
Sepsis

Question 26

How should the adenosine be administered?

Answer 26

Rapid bolus over 1-3 seconds followed by 20 ml IV Normal Saline bolus

Question 27

What will be absent of the ECG in someone with supaventricular tachycardia?

Answer 27

P waves

Question 28

What is the name of the possible extra electical pathway that can cause supraventricular tachycardia?

Answer 28

Wolff-Parkinson-White syndrome

Question 29

What is the half life of adenosine?

Answer 29

8-10 seconds