Assessment of normal left atrial appendage anatomy and function over gender and ages by dynamic cardiac CT.

OBJECTIVES: The aim of this study was to evaluate variations in anatomy and function according to age and gender using cardiac computed tomography (CT) in a large prospective cohort of healthy patients. BACKGROUND: The left atrial appendage (LAA) is considered the most frequent site of intracardiac thrombus formation. However, variations in normal in vivo anatomy and function according to age and gender remain largely unknown. METHODS: Three-dimensional (3D) cardiac reconstructions of the LAA were performed from CT scans of 193 consecutive patients. Parameters measured included LAA number of lobes, anatomical position of the LAA tip, angulation measured between the proximal and distal portions, minimum (iVolmin) and maximum (iVolmax) volumes indexed to body surface area (BSA), and ejection fraction (LAAEF). Relationship with age was assessed for each parameter. RESULTS: We found that men had longer and wider LAAs. The iVolmin and iVolmax increased by 0.23 and 0.19 ml per decade, respectively, while LAAEF decreased by 2% per decade in both sexes. CONCLUSIONS: Although LAA volumes increase, LAAEF decreases with age in both sexes. KEY POINTS: • Variations in normal left atrial appendage in vivo anatomy and function remain largely unknown. • Cardiac CT is reliable for left atrial appendage volume measurements. • Although LAA volumes increase, LAAEF decreases with age in both sexes.