Wolff-Parkinson-White syndrome Flashcards
definition
genetic condition where there is an accessory pathway causing abnormal cardiac conduction, a pre-excitation syndrome which can lead to ventricular tachycardia, cardiac arrest and death
who is it more common in?
men
what can it be associated with
congenital structural and other structural cardiac abnormalities - cardiomyopathies and valve defects such as mitral valve prolapse
diagnosis
echo ECG routine bloods/FBC 24 hour holter monitoring stress testing electrophysiology studies
role of echo
check for structural abnormalities
role of FBC
to exclude other causes, will be normal
role of 24 hour holter monitoring
to capture arrhythmias
role of stress testing
to elicit arrhythmias
role of electrophysiology studies
to show accessory pathway for ablation
clinical features
often asymptomatic can present with AF or atrial flutter acute episodes ventricular tachycardia/cardiac arrest acute episodes followed by polyuria
acute episode symptoms
shortness of breath syncope dizziness palpitations chest pain
ECG changes
delta wave short P-R interval non-specific T wave changes AF antidromic conduction orthodermic conduction ST changes pre-excitation
what is a delta wave?
upward slurring of R wave - makes QRS broad
types
A and B
type A ECG changes
positive delta wave and positive QRS in all leads
looks like RBBB
type B ECG changes
negative delta wave and negative QRS in V1 and V2 but positive in other chest leads - looks like LBBB
AF on ECG
> 200bpm
irregular
wide QRS due to bypassing of AVN
antidromic conduction on ECG
200-300bpm
wide QRS due to accessory pathway
orthodermic conduction on ECG
retrograde conduction 200-300bpm no P waves narrow QRS (<120ms) T wave inversion ST depression
ST changes
occur in opposite direction to QRS complex
pre-excitation
occurs during the time outside of acute episodes
how often does atrial flutter occur?
7%
how often does AF occur?
20%
atrial flutter and fibrillation
can lead to ventricular fibrillation or tachycardia due to transfer of rapid atrial rate to ventricles via accessory pathways
