[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.

[Prevalence and electrocardiographic forms of the Wolff-Parkinson-White syndrome].

In a routine electrocardiographic study of 133929 subjects aged from 20 to 73, 136 cases of the Wolff-Parkinson-White syndrome were detected, 6 with intermittent pre-excitation. In this study, the prevelance of WPW was about 1 in a 1000, the highest incidence being in the 20-40 year age group with an equal sex ratio. The ECG analysis of the 136 cases consisted in determining the orientation of the delta wave in the precordial leads to establish the right or left ventricular origin of the pre-excitation, calculating the direction of the delta wave vector in the frontal plane to find out the anterior, lateral or posterior origin of the pre-excitation and analyse the position of the QRS axis to assess the appearances of the latest ventricular activity.