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.