Detected atrial arrhythmias with the 12-lead Holter System in Patients complaining of palpitations with normal 12-lead ECGs - gender and age differences

Objective. hypoestrogenemia in postmenopausal female has important effects on the heart with possible arrhythmic consequences. we studied the prevalence of atrial arrhythmias in 12-lead holter in patients with normal baseline ecgs. we used morphologic ecg data to define the origin of the arrhythmias. methods. twelve lead holter recordings in 172 consecutive patients in the community were analyzed. the prevalence of ectopic and reentry nonsustained atrial tachycardia (nsat),atrial fibrillation,atrial flutter,and right and left premature atrial complexes,was studied in men and women. patients aged ≥50 years and <50 years were analyzed separately. results. premature atrial complexes were frequent in all the four groups. in women aged ≥50 years,the prevalence of ectopic nsat was 57%. women aged ≥50 years,who showed episodes of atrial fibrillation or flutter,had a prevalence of concomitant ectopic nsat of 67 %. all the nsat episodes were repetitive (≥10 episodes/24h). there was a striking gender difference,as the corresponding number for men in the same age group was only 17 %. conclusions. ectopic nsat is frequently associated with atrial fibrillation or flutter in women aged ≥50 years. we propose a hypothesis related to hormone metabolism and collagen expression in the heart to explain this phenomenon.