[Prevalence of hyperkinetic arrhythmias in a healthy infantile and adolescent population: correlations between standard ECG, stress test and dynamic ECG].

We evaluated 250 males and 250 females 4 to 17.99 years old, randomly recruited among school-children. Cardiac and other diseases were excluded. All the subjects were studied with a standard ECG iun the standing and supine position for a minute. Three hundred children underwent a treadmill exercise test according to Bruce's protocol and 50 of them had a 24-hour ambulatory ECG monitoring. Sinus arrhythmia was present in 94% of the children in supine position and in 87% of them while they were standing. Only one child had atrial and ventricular premature beats. In a boy a slow ventricular tachycardia was recorded. One child had a WPW and a girl a short PR interval; both were asymptomatic. The exercise test did not induce any arrhythmias and the slow ventricular tachycardia, in the previously mentioned boy was suppressed during exercise and reappeared during the recovery period. The premature beats were greatly reduced in the child who had them during the standard ECG recording. The 24-hour ambulatory ECG monitoring showed only minor degrees of premature atrial and ventricular beats in 24% of the children studied by this method. The maximum number of premature beats was 39 in 24 hours and never exceeded the first grade of Lown's classification. We conclude that a good correlation exists among the three employed techniques in the study of the prevalence of tachyarrhythmias in healthy children. This is the first study that compares these three techniques in a pediatric population.