[Prevalence and course of Wolf-Parkinson-White syndrome in a population of 138,048 subjects].

The prevalence of the Wolff-Parkinson-White (WPW) syndrome, frequency of arrhythmias and their evolution were studied in a group of volunteers consisting in 79,978 men and 59,070 women, aged from 20 to over 70. The higher prevalence of WPW in men than in women (p less than 0.001) decreased significantly with age, much more in men (p less than 0.001) than in women (p less than 0.05). Ventricular pre-excitation was intermittent in 6.7 p. 100 of men and in 16 p. 100 of women. The probable site of pre-excitation, determined on the orientation of the delta wave was more often left than right (104 vs 66, p less than 0.02). The frequency of paroxysmal tachycardia increased with age: 10 p. 100 of the cases from 20 to 39 years of age, 29 p. 100 from 40 to 59, 36 p. 100 at 60 and over (p = 0.05). It was 1.7 times more frequent in cases of left pre-excitation. A hundred and fifty-one patients were followed-up from 1 to 11 years (4.6): 5 patients died, 3 of non-cardiac and 2 of undetermined causes, with one sudden death in a 29 year old man. Fifty-three patients were reviewed 4.5 years after the initial examination: 9 pre-excitations (7 right, 2 left) had disappeared. In conclusion, the higher prevalence of WPW in men decreases with age. This decrease appears to be essentially due to the disappearance of the ventricular pre-excitation and not to an increased mortality. Arrhythmias are more frequent in older patients with left-sided pre-excitation.