Evaluation of left atrial appendage functions by transesophageal echocardiography in patients with hyperthyroidism

Objectives: We evaluated the contractile function of the left atrial appendage, an important anatomical structure in the pathogenesis of systemic embolism, by transesophageal echocardiography in patients with hyperthyroidism.
Study design: Transthoracic and transesophageal echocardiography were performed in four patient groups having the following features: hyperthyroid patients with atrial fibrillation (group I, n=23), hyperthyroid patients with sinus rhythm (group II, n=22), control patients with atrial fibrillation (group III, n=12), and control patients with sinus rhythm (group IV, n=12). Transthoracic and transesophageal echocardiography findings were compared between groups I and III, and groups II and IV.
Results: No significant differences were found between the groups with respect to standard transthoracic echocardiography parameters. In transesophageal echocardiography, the emptying (0.5 m/s vs 0.3 m/s, p=0.028) and filling (0.5 m/s vs 0.4 m/s, p=0.015) velocities of the left atrial appendage were found to be significantly higher in group I than in group III. Similarly, compared to group IV, group II had significantly higher emptying (0.7 m/s vs 0.4 m/s) and filling (0.7 m/s vs 0.4 m/s) velocities (p=0.0001).
Conclusion: Our results show that the contractile functions of the left atrial appendage are preserved in patients with hyperthyroidism, suggesting a lower risk for hemostasis and thrombus formation.

Keywords: Atrial function, echocardiography, transesophageal; heart atrium/ultrasonography; hyperthyroidism.