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Wolff-Parkinson-White pattern on alternate beats: What is the mechanism?
Vincenzo Carbone1, Ferdinando Ferrara2, Antonio Cassese1
1Outpatient Cardiology, Naples, Italy.
Abstract:
The Holter electrocardiogram from an asymptomatic man shows intermittent preexcitation. At the lowest rates all the QRS complexes display a WPW pattern. As the rate increases, preexcitation fails to occur and all the QRS complexes become persistently narrow. With a further increase in sinus rate the WPW occurs on alternate beats and this alternation is maintained for a while. A careful analysis of the accessory pathway conduction in relation to sinus-cycle length and morphology of the prior beat strongly supports the supernormal conduction through the Kent bundle associated with linking as the key mechanism underlying the preexcitation on alternate beats.
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