Serial changes of left atrial thrombus in mitral stenosis: transesophageal echocardiographic studies in candidates for balloon mitral commissurotomy.

BACKGROUND

Little is known concerning therapeutic modification of left atrial thrombus in mitral stenosis and its formation after successful balloon valvuloplasty (percutaneous transvenous mitral commissurotomy [PTMC]).

OBJECTIVE

To test the roles of the clinical use of anticoagulant therapy and PTMC, serial changes in left atrial thrombus were examined by transesophageal echocardiography in 80 patients with mitral stenosis.

RESULTS

No difference in embolic history, New York Heart Association functional class, cardiac rhythm, left atrial size or mitral valve area was found between patients with (n=23) and without (n=57) left atrial thrombus. Diuretic use was the prevalent factor for left atrial thrombi, which were dissolved completely in seven (30.4%) and partially in eight (34.7%) of the patients by adequate warfarin. However, after PTMC (n=53), newly formed thrombus was observed in four of 51 (7.8%) patients, which correlated with left atrial size (at least 50mm), atrial fibrillation and poorly controlled warfarin (thrombo test: 63.8 +/- 18.8% versus 35.9 +/- 17.7%, P<0.005). The newly formed thrombi were dissolved within several weeks.

CONCLUSION

Left atrial thrombus in symptomatic mitral stenosis exhibits elusive characteristics and should be strictly monitored even after successful PTMC by transesophageal echocardiography in order to achieve adequate anticoagulation.