Benign nature of atrial dissociation in pediatric patients.

Atrial dissociation is defined electrocardiographically by the presence of an ectopic atrial rhythm depolarizing independently of the basic sinus rhythm, and is characterized by entrance and exit block. Atrial dissociation is most often observed as an ominous sign in adults with severe myocardial dysfunction. We have observed atrial dissociation in 3 pediatric patients, aged 5 to 22 years, who were essentially asymptomatic from this arrhythmia. All 3 patients are well, without therapy for atrial dissociation, during a follow-up period of 1 to 5 years. The benign nature of atrial dissociation in the pediatric patient as compared with the adult is stressed.