2 - Paeds - CVS - Supraventricular Tachycardia Flashcards
how common? rapid HR - what bpm? can cause what?
most common childhood arrhythmia
250 -300 bpm
can cause poor cardiac output and pulm oedema
Presentation?
Can cause hydrops fetalis and intrauterine death
increased HR and Sx of HF in neonate/young infant
Pathology of SVT
AKA - re-entry tachycardia
- circuit of conduction set up with premature activation of atrium via accessory pathway
rarely a structural problem
What may be seen on ECG?
what if HF severe? what seen if sinus rhythm? what if WPW syndrome?
narrow complex tachy - 250-300bpm
p waves maybe after the QRS (retrograde atrial activation via accessory pathway)
if HF severe - possible ischaemic changes (T wave inversion)
is sinus rhythm - may be short P-R interval
(with delta wave if WPW)
MGMT - 1st thing in severely ill child? then what?
- 1 - restore sinus rhythm
- maintenance therapy with sotalol or flecainide - digoxin may be used alone if no overt delta wave (propranolol added if there is)
how to restore sinus rhythm? 4 parts
- circulatory and resp support (PPV if needed, correct acidosis)
- vagal stimulation maneouvers - cold ice pack to face, carotid sinus massage
- IV adenosine
- electrical cardioversion with synch DC shock if adenosine fails
IV adenosine - why used? what does it do after rapid bolus injection? breaks what? how given?
1st line, safe, effective
induces AV block after rapid bolus
terminates tachycardia by breaking re-entry circuit
given incrementally
what happens to resting ECG … % with attacks after infancy? Tx stopped when?
remains abnormal
90% no further attacks after infancy
Tx stopped at 1y
What if WPW?
teenage assessment maybe needed with atrial pacing to reduce chance of sudden death
what if relapse??
percutaneous radiofrequency ablation/cryoablation of re-entry
