Left atrial appendage morphology with the progression of atrial fibrillation

Left atrial appendage (LAA) size is crucial for determining the indication of transcatheter LAA closure. The aim of this study was to evaluate the differences in LAA morphology according to the types of atrial fibrillation (AF). A total of 299 patients (mean age: 67 ± 13 years) who underwent transesophageal echocardiography (TEE) were included. Patients were classified into non-AF (n = 64), paroxysmal AF (n = 86), persistent AF (n = 87), or longstanding persistent AF (n = 62). LAA morphology, including LAA ostial diameter and depth, was assessed using TEE. Patients with long-standing persistent AF had larger LAA ostial diameter and depth and lower LAA flow velocity. The maximum LAA ostial diameter was 19 ± 4 mm in patients with non-AF, 21 ± 4 mm in patients with paroxysmal AF, 23 ± 5 mm in patients with persistent AF, and 26 ± 5 mm in patients with long-standing persistent AF. LAA ostial diameter was increased by 2 or 3 mm with the progression of AF. LAA ostial diameter was correlated with LA volume index (R = 0.37, P < 0.01) and the duration of continuous AF (R = 0.30, P < 0.01), but not with age or the period from the onset of AF. In conclusion, LAA size was increased with the progression of AF.