Left atrial appendage anatomy: clinical implications for cardiac procedures

Area of Science:

• Cardiology
• Anatomy
• Medical Imaging

Background:

• The Left Atrial Appendage (LAA) is a primary source of thrombi in atrial fibrillation (AF), increasing stroke risk.
• Interventional procedures targeting the LAA are becoming more common due to rising AF prevalence.

Purpose of the Study:

• To provide detailed anatomical data of the LAA relevant to exclusion and ablation procedures.
• To analyze morphological and morphometric variations of the LAA in a cadaveric cohort.

Main Methods:

• Examination of 50 formalin-fixed cadaveric hearts.
• Detailed recording of LAA morphological and morphometric parameters, including shape, orifice characteristics, and surrounding structures.

Main Results:

• The most common LAA shapes were Cauliflower (36%) and Chicken Wing (34%).
• LAA orifices were predominantly oval (64%) with a greater horizontal diameter.
• Diverticular 'divots' were observed in 36% of cases, primarily on the septal and posterior walls.
• The circumflex artery was within 5 mm of the LAA orifice in 76% of specimens.
• Non-Chicken Wing LAA morphology correlated with proximity to the circumflex artery, high orifice ovality, and increased divots.

Conclusions:

• LAA anatomy exhibits significant variability, posing challenges for interventional procedures.
• This anatomical data can aid clinicians in planning and executing LAA-focused cardiac interventions.
• Understanding LAA variations is essential for improving procedural success rates and patient outcomes in AF management.