Approach to Tachycardia

Question 1

1st step in approaching patient with tachycardia?

Answer 1

ABCDE to determine if they are stable or unstable.

Question 2

What are some signs of an unstable patient with tachycardia?

Answer 2

1) Shock: hypotension (<90 mmHg), pallor, sweating, cold, clammy extremeties, confusion or impaired conciousness.

2) Syncope

3) Myocardial ischaemia

4) HF

Question 3

If any adverse signs are present in a patient with tachycardia, what is the next step?

Answer 3

Synchronised DC shocks.

Up to 3 shocks can be given –> then seek expert help.

Question 4

How many synchronised DC shocks can be given in unstable patients with tachycardia?

Answer 4

Up to 3 - then seek expert help

Question 5

What history may be present in patients with tachycardia?

Answer 5

• palpitations
• exercise intolerance
• lightheadedness
• syncope

Question 6

Key investigation in tachycardia?

Answer 6

ECG –> assess regular or irregular, broad or narrow complex.

Question 7

If patient with tachycardia is stable, what is next step?

Answer 7

Get an ECG –> determine if the QRS if narrow or broad.

Question 8

What is a narrow QRS?

Answer 8

<120ms

Question 9

What is a broad QRS?

Answer 9

> 120ms

Question 10

What does a narrow complex tachycardia indicate?

Answer 10

That the pacing originates above the ventricles –> suggests you are dealing with SVT (if regular).

Question 11

Stepwise mx of regular narrow complex tachycardia? (4)

Answer 11

1) Vagal manoeuvres

2) IV adenosine (monitor ECG continuously):
- 6mg rapid IV bolus
- 12mg
- 18mg

3) Verapamil or beta blocker

4) Synchronised DC shock up to 3 atttempts (sedation or anaesthesia if conscious)

Question 12

Mx of sinus tachycardia?

Answer 12

Treat cause e.g. fever, anxiety, pain, exercise, hyperthyroidism, pregnancy, anaemia.

Question 13

What are some vagal manoeuvres used in narrow complex regular tachycardia? (3)

Answer 13

1) valsalva manoeuvre

2) applying a cold stimulus to the face e.g. application of a bag filled with ice and cold water over the face for 15-30 secs

3) carotid sinus massage

Question 14

What do Valsalva manoeuvres commonly used include?

Answer 14

1) forceful exhalation against a closed airway for approximately 15-20 seconds

2) blowing into an occluded straw

3) adopting a head-down position for approximately 15-20 seconds

Question 15

When is a carotid sinus massage contraindicated?

Answer 15

If any history of carotid artery disease

Question 16

If adenosine is contra-indicated or fails in the management of SVT, what is the 2nd line medication?

Answer 16

Verapamil –> given IV over a two-minute period

Question 17

What is an irregular narrow-complex tachycardia most likely to be?

Answer 17

Atrial fibrillation (or less commonly atrial flutter with a variable atrio-ventricular block)

Question 18

Mx of AF with duration of <48 hours?

Answer 18

Can be offered rhythm control or rate control.

Note –> rhythm control is recommended in most patients with a new onset of AF presenting at this time.

Question 19

What are the options for rhythm control in AF <48 hours?

Answer 19

1) DC Cardioversion,

2) Chemical cardioversion:
- flecainide
- propafenone
- amiodarone

Question 20

When can flecainide & propafenone not be used in rhythm control of AF?

What can be used instead?

Answer 20

If evidence of structural heart disease or HF.

Use amidarone or digoxin instead.

Question 21

Mx of AF >48 hours?

Answer 21

Do not treat with cardioversion until they have been anti-coagulated for at least 3 weeks, to reduce the risk of dislodging an atrial thrombus.

Question 22

If a patient with AF >48 hours BUT is unstable and requires urgent cardioversion, what do you do?

Answer 22

Give LMWH or UH first

Heparin treatment as well as oral anti-coagulation should be commenced after cardioversion (whether successful or not)

Question 23

What is aim of rate control of AF?

Answer 23

To decrease the heart rate at rest and during exertion

Symptoms are normally associated with high heart rates.

Question 24

What medications can be used for rate control of AF?

Answer 24

1) Beta blockers

2) Non-dihydropyridine calcium channel blockers e.g. verapamil and diltiazem

3) Digoxin (but not recommended outside of sedentary patients with non-paroxysmal AF)

Question 25

Which beta blocker is NOT used for rate control in AF?

Answer 25

Sotalol –> used for rhythm control

Question 26

When is long term management of SVT indicated?

Answer 26

If the frequency and severity of SVT episodes significantly impacts on the patients quality of life and functioning:

Indications for definitive or long-term treatment include:

1) Recurrent symptomatic SVT episodes affecting quality of life

2) Evidence of Wolff-Parkinson-White on ECG and symptoms of SVT episodes

3) Infrequent SVT episodes but in a profession or sport which puts themselves or others at risk (e.g. drivers, pilots, surgeons)

Question 27

What are some options for long term mangement of SVT?

Answer 27

1) Radio-frequency ablation is often preferred due to the low risk of complications and high success rate (>95%)

2) Pharmacological treatment usually involves beta blockers or calcium-channel blockers as a first-line option (if ablation declined)

3) Second-line medication options include flecainide and sotalol

Question 28

What is broad complex regular tachycardia caused by?

Answer 28

Assume ventricular tachycardia (VT) - unless previously confirmed SVT with bundle branch block.

Question 29

Mx of VT?

Answer 29

1) Loading dose of amiodarone 300mg IV over 10-60 mins. Followed by 24 hour infusion.

2) Synchronised DC shock up to 3 times

Question 30

What is the loading dose of amiodarone given in VT?

Answer 30

300mg IV over 10-60 mins

Question 31

Mx of broad complex regular tachycardia with previously confirmed SVT with BBB?

Answer 31

Treat as for regular narrow complex tachycardia

Question 32

Causes of broad complex irregular tachycardia?

Answer 32

1) AF with BBB (most common)

2) Polymorphic VT e.g. torsades de pointes

Question 33

Mx of AF with BBB?

Answer 33

Seek expert help

Treat as for irregular narrow complex tachycardia

Question 34

Mx of polymorphic VT (e.g. torsades de pointes)?

Answer 34

Magnesium 2g over 10 mins