SVT

Question 1

SVT caused by

Answer 1

electrical signal re-entering the atria from the ventricles

Question 2

duration of QRS in SVT

Answer 2

less than 125 ms

Question 3

DDx of narrow complex tachycardia

Answer 3

SVT- QRS regular + narrow + fast

AF- QRS irregular

Flutter- atrial rate usually less then 300bmp

Question 4

SVT and BBB can lead too

Answer 4

SVT with broad complex tachycardia

Question 5

WPW can be identified by…

Answer 5

slurred upstroke in the QRS and short PR ( normal PR 120-200)

Question 6

adenosine role in SVT

Answer 6

slows cardiac conduction, interrupting re-entry pathway resetting conduction
-cause a brief period of bradycardia/asystole

Question 7

acute management of unstable SVT

Answer 7

cardioversion

Question 8

name the long term management of SVT

Answer 8

medications: beta-blockers, calcium channel blockers, amiodarone
ablation

Question 9

outline a simple patho of the Valsalva

Answer 9

1. forceful exhalation: increased pressure in the thoracic pressure’
2. stimulates Strech receptors in PNS- vagal response, decreases HR
3. decreased venous return, SNS stimulated, increased HR
4. pressure released, back to baseline, large amounts of blood in the heart, increased Q, self regulates too normal.

Question 10

indication to use the SVT guideline

Answer 10

This guideline is for patients aged greater than or equal to 12 years with supraventricular tachycardia (SVT) and a ventricular rate greater than or equal to 150/minute. Seek clinical advice if the patient is aged less than 12 years

Question 11

management of SVT if the patient is not severely compromised

Answer 11

Attempt up to two Valsalva manoeuvres.

If the rhythm fails to revert get ICP for adenosine

Question 12

management of SVT if the patient is severely comprised

Answer 12

Reconsider the diagnosis as it is rare for SVT to cause severe compromise.Do not administer adenosine as the risk of precipitating cardiac arrest is very high.

• if patient obeying commands disassociate and cardiovert

-if pt not obeying commands cardiovert in max souls sync mode, can be attempted one more time if fails

Question 13

patient who has a previous history of SVT and whose rhythm reverts to sinus rhythm following treatment should be given a clear recommendation to be seen in primary care for a review of their condition provided that:

Answer 13

There are no ongoing signs or symptoms of myocardial ischaemia, and
The patient is given a copy of their 12 lead ECG.

Question 14

identifying factor to differentiate if SVT is causing comp or an underlying conditions is

Answer 14

If the primary problem is SVT causing cardiovascular compromise, the patient will usually have been well before suddenly developing palpitations. If not, the diagnosis should be reconsidered.

Question 15

tips to differentiate between SVT and AF

Answer 15

When atrial fibrillation is very fast (ventricular rates of 160-200/minute) the rhythm can appear regular, like SVT.

When the rhythm is SVT the heart rate recorded on the monitor does not usually vary by more than one or two beats/minute. If the rhythm is very fast atrial fibrillation the heart rate recorded by the monitor will usually vary.

Question 16

outline the steps of a valsalva

Answer 16

Patients require coaching to produce a good Valsalva manoeuvre:
Place the patient in a sitting position.
Ask the patient to blow as hard as possible into a 20 ml (or larger) syringe to try and move the plunger.
Continue the manoeuvre for a minimum of 15-20 seconds.
When the patient stops blowing, simultaneously lay the patient flat and raise their legs.
If cardioversion occurs, it usually occurs after the end of the Valsalva manoeuvre.

Question 17

name some potential complications of the valsalva

Answer 17

syncope
Brady
prolonged hypotensive episode

Question 18

if unsure if patient is in SVT

Answer 18

-consider if it is narrow complex and regular 150-200 bpm
good indicator it is SVT
ask clinical if still unsure