Exercise testing and ambulatory monitoring in patients with preexcitation syndrome.

Documentation of arrhythmia in symptomatic patients with preexcitation syndromes may be difficult despite extended ambulatory monitoring (MON). We, therefore, examined 12 patients with Wolff-Parkinson-White (WPW) and ten with Lown-Ganong-Levine ECG anomalies to compare the yield of tachyarrhythmia on maximal treadmill testing (MTT) and on MON. Nineteen patients were free of associated heart disease. Average age for the group was 45 years (11 men and 11 women). Sustained atrial arrhythmias developed in four of 22 patients during MTT. All four were free of arrhythmia on subsequent MON. An additional four patients exhibited these arrhythmias on MON. We conclude that the use of both monitoring and exercise testing will enhance detection of arrhythmia in patients with symptomatic preexcitation.