AGE-RELATED-CHANGES IN THE CLINICAL AND ELECTROPHYSIOLOGIC CHARACTERISTICS OF PATIENTS WITH WOLFF-PARKINSON-WHITE SYNDROME - COMPARATIVE-STUDY BETWEEN YOUNG AND ELDERLY PATIENTS

The natural history of patients with Wolff-Parkinson-White (WPW) syndrome remains an intriguing question with respect to clinical decision-making, since serial electrophysiologic data spread over several decades in the same patient are not available in the literature. To study the age-related changes in WPW syndrome, we compared two separate groups of patients referred to this Medical Center for electrophysiologic studies because of a clinical presentation with significant arrhythmias. An elderly group of 42 patients aged 50 years or more were compared with a younger group of 51 patients aged 15 to 30 years. The groups were comparable in terms of clinical presentation, including the number of patients who had reported syncopal episodes and those requiring cardioversion of their tachyarrhythmias. Baseline electrophysiologic variables such as sinus rate; sinoatrial conduction time; corrected sinus node recovery time; AH interval; and effective refractor periods of the right atrium, atrioventricular (AV) node, and right ventricular muscle, were significantly greater in the elderly group. Similarly, the anterograde effective refractory period of the bypass tract, the shortest atrial pacing cycle length with 1:1 anterograde conduction via the bypass tract, retrograde effective refractory period of the bypass tract, the shortest ventricular pacing cycle length with 1:1 retrograde conduction via the bypass tract, the shortest consecutive preexcited R-R interval during atrial fibrillation, and the cycle length of orthodromic atrial ventricular reciprocating tachycardia were significantly greater in the elderly group. Although such an electrophysiologic milieu in the elderly group could be interpreted as more benign compared with the younger group of patients and thus conductive to less malignant tachyarrhythmias on a theoretical basis, both groups in fact had a comparable clinical profile including frequency of syncope and direct-current cardioversion. This could in part be due to the fact that the difference in the effective refractory period between the AV node and the bypass tract were comparable between the groups. Thus it is concluded that the management of WPW syndrome in symptomatic elderly patients should be as aggressive as in the younger patients, and radiofrequency or surgical ablation may have to be considered as the initial management option in these elderly patients.