Significance of left atrial thrombus in prediction of systemic arterial embolization in rheumatic mitral valve disease: a two-dimensional echocardiographic study
Lin, J.L.; Cheng, J.J.; Peng, H.C.; Lien, W.P.; Chen, J.J.; Chen, J.H.; Wu, K.K.
Journal of the Formosan Medical Association 88(9): 955-960
1989
ISSN/ISBN: 0371-7682 PMID: 2621438 Document Number: 335214
One of the most devastating complications in patients with rheumatic mitral valve disease is systemic arterial embolization, which is commonly attributed to dislodgement of left atrial thrombi. A study was performed to assess the potential value of two-dimensional echocardiography in detecting left atrial thrombi and predicting clinical embolic occurrence. Within a period of 2 years, a total of 132 consecutive patients with rheumatic mitral valve disease were examined. These included 97 with predominant mitral stenosis, 22 with predominant mitral regurgitation, and 13 with mitral valve replacement. Excluded were those with infective endocarditis, predominant aortic or tricuspid valve disease, and those with prosthetic valve dysfunction. Based on echocardiographic findings, these patients were divided into two groups: Group A, 31 patients with left atrial thrombi (predominant mitral stenosis, 22 patients; post-mitral valve replacement, 9 patients); and Group B, 101 patients without left atrial thrombi (predominant mitral stenosis, 75 patients; predominant mitral regurgitation, 22 patients; post-mitral valve replacement, 4 patients). Systemic arterial embolization occurred significantly more frequent in Group A than in Group B (45.2% vs 14.9%, p < 0.001). In patients with predominant mitral stenosis, embolic events also occurred significantly more often in those of Group A than in those of Group B (27.3% vs 13.3%, p < 0.05). In addition, atrial fibrillation rhythm was found to be more common in Group A than in Group B (96.8% vs 69.3%, p < 0.001). For patients with predominant mitral stenosis, atrial fibrillation also prevailed more often in Group A than in Group B (95.5% vs 70.0%, p < 0.001). Neverthless, global left atrial size did not differ significantly between the two groups, although various measurements revealed general enlargement of the left atrium in patients of both groups. Echocardiographic features of the left atrial thrombi (thrombal location, thrombal build, thrombal size) did not help much in predicting the incidence of systemic arterial embolization, except that those with larger thrombal size (>2.0 .times. 2.0 .times. 2.0 cm) were more prone to embolism than those with smaller ones (p < 0.05). However, patients with soft and floating left atrial thrombi were still at a much higher risk of systemic embolization than others, as experienced in one of our representative cases. In conclusion, patients with rheumatic mitral valve disease, who have left atrial thrombi detected by two-dimensional echocardiography, may well be regarded as a high-risk population for systemic arterial embolization. Adequate anticoagulation in advance should be considered.