Evolution of clinical and electrophysiologic data in patients with a preexcitation syndrome

The purpose of the study is to report the natural changes of preexcitation syndrome (PS).

Electrophysiologic study was performed for syncope (n = 8), atrioventricular reentrant tachycardia (AVRT) (n = 42), atrial fibrillation (n = 3), adverse presentation (n = 4), or for asymptomatic PS (n = 22) and was repeated 1 to 21 years later.

Clinically, 12 patients initially asymptomatic became symptomatic (54.5%), and 12 symptomatic patients became asymptomatic (21%). At electrophysiologic study 2, maximal rate conducted over accessory pathway (AP) was slower. Anterograde conduction disappeared in 22 patients, but 10 of them had inducible AVRT. Among 27 patients with initially rapid conduction over AP, 7 had a benign form; 20 had always a rapid conduction over AP, and 3 of them initially asymptomatic developed rapid atrial fibrillation.

Asymptomatic patients with a PS frequently became symptomatic (54.5%), whereas symptomatic patients rarely became asymptomatic (21%). Maximal rate conducted over AP decreased during life, but AVRT remained inducible.