Prevalence and natural course of ectopic atrial tachycardia

The purpose of this study was to calculate the prevalence of ectopic atrial tachycardia in a population of young asymptomatic males and to assess its natural course both in asymptomatic subjects and in symptomatic hospital patients.

12-lead electrocardiograms (ECG) of 3554 consecutive males applying for a pilot's licence were analysed. ECGs of symptomatic arrhythmia patients at two university hospitals were also analysed. A repeat ECG was taken in cases of ectopic atrial tachycardia to assess the natural course of this arrhythmia. Twelve out of 3554 asymptomatic subjects (prevalence 0.34%) and 17 out of 3700 symptomatic arrhythmia patients (prevalence 0.46%) had ECG evidence of ectopic atrial tachycardia. A repeat ECG was obtained after a mean follow-up of 8+/-3 years in asymptomatic subjects and 7+/-3 years in symptomatic patients. After the follow-up, seven (26%) out of 27 patients were still in a similar ectopic atrial rhythm, 10 (37%) showed a change in P wave morphology and 10 (37%) were in sinus rhythm. Heart rate was significantly slower (mean rate 81+/-19 vs 109+/-17 beats. min-1) in the repeat ECGs.

Asymptomatic ectopic atrial tachycardia is not an uncommon finding in a population of young males. The majority of patients show slowing of heart rate in the course of time, either with restoration of sinus rhythm or with a change in P wave morphology, suggesting that the ectopic foci undergo gradual degeneration with time.