# Congenital Absence of the Left Atrial Appendage and Possible Effects on Thrombosis: A Case Report

## TL;DR

This case report describes a rare congenital absence of the left atrial appendage and discusses its potential impact on stroke risk and treatment in atrial fibrillation.

## Contribution

The paper contributes a rare clinical case of congenital left atrial appendage absence and highlights its implications for thrombosis risk assessment.

## Key findings

- Congenital absence of the left atrial appendage was confirmed in a 64-year-old male.
- Current evidence does not support changing anticoagulation guidelines despite the anomaly.
- Standard management for atrial fibrillation should still be followed in such cases.

## Abstract

The left atrial appendage (LAA) is a common site for thrombus formation in atrial fibrillation (AF) and often the focus of imaging prior to cardioversion. We present a rare case of a 64-year-old male undergoing routine transesophageal echocardiography (TEE) prior to electrical cardioversion, during which the LAA was not visualized. Further evaluation confirmed congenital absence of the LAA - a seldom-reported finding with uncertain implications for stroke risk and anticoagulation management. This report adds to the limited literature on this anomaly and underscores the importance of a systematic approach when faced with unexpected imaging findings. Although the absence of the LAA might theoretically reduce thromboembolic risk, current evidence is insufficient to alter management, and standard anticoagulation guidelines for AF should still be followed.