Objective To explore the electrophysiological characteristics and ablation prognosis of atrial flutter in elderly patients, which was associated with the spontaneous scar on the anterior wall of the left atrium.

Methods Electrophysiological examination and radiofrequency ablation (RFA) were performed in 5 elderly patients (3 males and 2 females) from January 2018 to January 2020 in Minhang Hospital, Fudan University. These 5 elderly patients with atrial flutter associated with spontaneous scar on the anterior wall of the left atrium received radiofrequency ablation guided by three-dimensional electrical anatomy instruction. The average age was (76.6±10.5) years old. All patients had persistent atrial flutter. The diagnosis, mechanism, key isthmus, and the relationship between the spontaneous scar and low-voltage area of the anterior wall of the left atrium, were determined by activation mapping, entrainment mapping, and voltage mapping.

Results Enlarged left atrium was found in all of the 5 cases. The diameter of ascending aorta was widened in 3 patients. Low voltage and scar areas were mapped in the anterior wall of the left atrium adjacent to the pressure trace of ascending aorta in all 5 patients. The mechanism of 5 flutter cases was reentry. The key isthmuses were located in the local low voltage area. After ablation, the atrial flutters were all successfully terminated. One patient underwent circumferential pulmonary vein ablation at the same time because of the enlarged left atrium. And one patient underwent secondary ablation after recurrence. After an average follow-up period of (15.6±4.2) months, no recurrence was found.

Conclusions The spontaneous scar of the anterior wall of the left atrium may be the pathogenesis matrix of atrial arrhythmia in some elderly patients. The mechanism of atrial flutter is reentry. The enlarged left atrial and ascending aorta may be related to the formation of low voltage area of the scar on the anterior wall of the left atrium.