Guidelines for Management of Asymptomatic Ventricular Pre-excitation
Brave New World or Pandora’s Box?
The occurrence of sudden cardiac death in asymptomatic children is a rare but feared event. Ventricular pre-excitation (referred to as Wolff–Parkinson–White syndrome when associated with symptoms of supraventricular tachycardia) is one of the underlying causes of such events, with the mechanism of sudden death attributed to rapid antegrade conduction of atrial tachycardias via the accessory pathway resulting in ventricular fibrillation. Although estimates of the lifetime risk of mortality secondary to this ECG pattern vary somewhat, most suggest this risk to be in the range of 1:1000 pts/yr.1–3 Patient factors suggested to be associated with an increased risk for sudden cardiac death include inducibility of tachycardia, male sex, presence of multiple accessory pathways and, most importantly, the capacity of the accessory pathway to perform rapidly.1,3–5 Most patients whose initial presentation was a life-threatening event have an accessory pathway capable of conducting at cycle lengths faster than 220 to 250 ms.1,3,6,7
Article see p 218
It is disconcerting that studies have identified previously asymptomatic children with ventricular pre-excitation whose initial and only symptom was ventricular fibrillation.1,6,8 Although it would seem reasonable to assume that patients with symptoms of tachycardia were somehow at higher risk for these potentially lethal complications, the risk profiles of symptomatic and asymptomatic patients may in fact be similar.9 Asymptomatic patients in the past have been incidentally discovered, but increasingly they are identified as a result of ECG screening before sports participation or medication prescription. It is estimated that more than half of adolescents with ventricular pre-excitation are asymptomatic.2,10
Catheter ablation seems to be effective at eliminating the risk of sudden cardiac death in patients with ventricular pre-excitation, and it has become widely available as …