Loss of ventricular preexcitation during noninvasive testing does not exclude high-risk accessory pathways: A multicenter study of WPW in children
Abstrakt
Background: Abrupt loss of ventricular preexcitation on noninvasive evaluation, or nonpersistent preexcitation, in Wolff-Parkinson-White syndrome (WPW) is thought to indicate a low risk of life-threatening events. Objective: The purpose of this study was to compare accessory pathway (AP) characteristics and occurrences of sudden cardiac arrest (SCA) and rapidly conducted preexcited atrial fibrillation (RC-AF) in patients with nonpersistent and persistent preexcitation.
Methods: Patients 21 years or younger with WPW and invasive electrophysiology study (EPS) data, SCA, or RC-AF were identified from multicenter databases. Nonpersistent preexcitation was defined as absence/sudden loss of preexcitation on electrocardiogram, Holter monitoring, or exercise stress test.
RC-AF was defined as clinical preexcited atrial fibrillation with shortest preexcited R-R interval (SPERRI) <= 250 ms. AP effective refractory period (APERP), SPERRI at EPS, and shortest preexcited paced cycle length (SPPCL) were collected.
High-risk APs were defined as APERP, SPERRI, or SPPCL <= 250 ms. Results: Of 1589 patients, 244 (15%) had nonpersistent preexcitation and 1345 (85%) had persistent preexcitation.
There were no differences in sex (58% vs 60% male; P=.49) or age (13.3+-3.6 years vs 13.1+-3.9 years; P=.43) between groups. Although APERP (344+-76 ms vs 312+-61 ms; P<.001) and SPPCL (394+-123 ms vs 317+-82 ms; P<.001) were longer in nonpersistent vs persistent preexcitation, there was no difference in SPERRI at EPS (331+-71 ms vs 316+-73 ms; P=.15).
Nonpersistent preexcitation was associated with fewer high-risk APs (13% vs 23%; P<.001) than persistent preexcitation. Of 61 patients with SCA or RC-AF, 6 (10%) had nonpersistent preexcitation (3 SCA, 3 RC-AF).
Conclusion: Nonpersistent preexcitation was associated with fewer high-risk APs, though it did not exclude the risk of SCA or RC-AF in children with WPW.