[An analysis of the factors and phenomena associated with the formation of a spontaneous echo contrast in the left atrium].

INTRODUCTION AND AIMS: To determine the factors related to the formation of spontaneous echo contrast in left atrium.

PATIENTS AND

METHODS

We have analyzed our series of 1,066 patients undergoing transesophageal echocardiography until December 1991. It was found in left atrium in 387 patients (36%) and was associated with another pathology in 99%. We defined spontaneous echo contrast as mild in 64% and severe in 36%.

RESULTS

The prevalence of spontaneous echo contrast was greater in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.001), double mitral lesion (p < 0.001), prosthesis (p < 0.001), embolism (p < 0.05) and a dilated left atrium (left atrial dimension greater than 60 ml) (p < 0.01). The presence of mitral regurgitation made it less frequent (p < 0.05). Thrombi were visualized in 104 patients and they were more frequent in the presence of spontaneous echo contrast. Severe spontaneous echo contrast was significantly more frequent in patients with atrial fibrillation (p < 0.001), mitral stenosis (p < 0.05) and thrombi (p < 0.001).

CONCLUSIONS

Spontaneous echo contrast in left atrium is a common finding in transesophageal studies and it is associated with another pathology in 99%. It is more frequent in patients with atrial fibrillation, mitral stenosis, embolism or prosthesis. Left atrial enlargement is one of the more important factors. It is less frequent in patients with mitral regurgitation. Thrombi are less frequent in patients without spontaneous echo contrast. Severe spontaneous echo contrast is significantly associated with mitral stenosis, atrial fibrillation and left atrial thrombi.