Risk stratification in Wolff-Parkinson-White syndrome: the correlation between noninvasive and invasive testing in pediatric patients.

BACKGROUND: In Wolff-Parkinson-White (WPW) syndrome, rapid antegrade conduction of atrial tachyarrhythmias can result in ventricular fibrillation and sudden death. Antegrade conduction can be assessed through noninvasive testing or invasive electrophysiology study (EPS). We aimed to determine the correlation between noninvasive testing and EPS in a pediatric WPW population.
METHODS: All WPW patients <21 years who underwent EPS over a 10-year period were identified. Noninvasive testing reviewed included electrocardiogram, Holter, and exercise stress test (EST). Patients were classified as low-risk if preexcitation was lost during any test. EPS data reviewed included antegrade conduction during atrial pacing and atrial fibrillation. Conduction through the accessory pathway (AP) to a cycle length ≤ 250 ms was considered rapid, otherwise patients were nonrapid. Sensitivity, specificity, positive (PPV), and negative predictive value (NPV) of noninvasive testing to correctly identify nonrapid conduction was calculated.
RESULTS: There were 135 EPS. Twenty-four patients (18%) were classified low-risk noninvasively. Two of the 24 (8%) had rapid conduction at baseline EPS. The sensitivity, specificity, PPV, and NPV of low-risk noninvasive testing to predict nonrapid conduction was 22%, 94%, 92%, and 31%, respectively. Sixteen of the 24 had low-risk EST and none had rapid conduction at baseline EPS. The specificity and PPV of low-risk EST were 100%.
CONCLUSION: Loss of preexcitation during noninvasive testing had high specificity and PPV for nonrapid antegrade conduction during baseline EPS. Abrupt loss of preexcitation during EST was a highly reliable noninvasive marker of nonrapid AP conduction at baseline in our pediatric WPW patients. ©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.