Pathophysiological background and prognosis of common atrial flutter in non-elderly patients: Comparison to Atrial Fibrillation.

Background: It is unclear whether there is any difference in the background and prognosis between non-elderly patients who undergo catheter ablation of atrial fibrillation (AF) and common atrial flutter (CAFL).

Purpose: To investigate the difference between the patient background of both CAFL and AF in the non-elderly.

Methods: In 526 consecutive patients who underwent catheter ablation of clinical paroxysmal/persistent CAFL or AF in our hospital, we enrolled only patients under 60 years old. Cases harboring both AFL and AF were excluded. We analyzed the patient characteristics, echocardiographic findings, electrocardiographic (ECG) abnormalities during sinus rhythm, and clinical course after ablation.

Results: In total, 196 patients (Cohort 1: 142 males, 156 AF cases) were analyzed. AFL patients were younger than AF patients (47.4 ± 10.6 vs. 50.2 ± 6.4years, p = 0.031) and organic heart disease (OHD) was significantly more common in AFL patients than AF patients (42.5% vs. 11.5%, p<0.001). In 161 patients excluding OHD (Cohort 2), ECG abnormalities were more frequent in AFL than in AF patients (78.3% vs. 39.1%, p = 0.001). There were no significant differences in all-cause death, onset of heart failure, and cerebral strokes. On the other hand, the number of cases that required a pacemaker was significantly higher in the CAFL group than AF group (0.0% vs. 26.1%, p-value <0.001). These results suggested that CAFL may reflect occurrence of any atrial myocardial damage, even if it does not lead to heart failure.

Conclusions: Our present study suggested that CAFL may be associated with a broader atrial myocardial disorder in non-elderly patients.