Wolff–Parkinson–White syndrome

Background

- usually 150- 300 bpm

Diagnosis

1- short PR interval <0.12 sec

2- QRS duration >0.10 sec

3- delta wave/ slurred upstroke

- short PR interval due to loss of normal AV node conduction delay

- delta wave due to early activation of vent myocardium

Orthodromic Tachycrd

- the accessory path used for retrograde reentry conduction and AV node used for anterograde conduction. QRS is narrow, delta wave absent

- TX with CA channel blockers, beta blockers, procainamide, adenosine.

- Cardiovert (sync) if unstable with 50- 100J (0.5- 2J/kg for kids)

Antidromic Tachycrd

- access path used for anterograde conduction and AV node used for retrograde reentry.

- do not use beta blckrs of ca chnnl blckrs since will block down AV node only and not acc path and will actually speed up arrhythmia.

- TX with procainamide- 100mg q10 min until arrhrythmia terminated or max dose of 1000mg given. If no success, then cardiovert.

- Cardiovert (sync) if unstable with 50- 100J (0.5- 2J/kg for kids)

DDX

- idiopathic

- hypertrophic cardiomyopathy

- transposition of great vesses

- endocardial fibroelastosis

- mitral valve prolapse

- tricuspid atresia

- ebstein disease

Disposition

Admission:

- admit if cardioverted, chest pain, CHF, electrolyte imbalance.

- if easily terminated can be discharged with outpt electrophysiological study