The Factors Causing Left Atrial Appendage Clot Formation in Patients With Severe Rheumatic Mitral Stenosis

Abstract

Background: Rheumatic mitral stenosisis still present in the developing world. Left atrial appendage
clot is a common complication of mitral stenosis. The management differs significantly
if there is presence of clot.
Objective: We assessed the factors responsible for left atrial appendage clot formation in patients
with severe mitral stenosis through transesophageal echocardiography
Methods: An observational study was conducted among 82 (73 females, mean age 35.8±11.8
years) patients with severe mitral stenosis who underwent transesophageal echocardiography
before percutaneous transmitral commisurotomy. Patients were classified into two groups based
on the presence or absence of left atrial thrombus. Group l consisted of 24 patients (women to
men ratio 91:9) with left atrial thrombus, while group 2 consisted of 58 patients (women to men
ratio 88:12) without left atrial thrombus. Transesophageal echocardiographic findings were
reviewed in all patients.
Results: There was no significant difference between the two groups in terms of age, sex,
systolic pulmonary artery pressure and mitral valve mean pressure gradient (MVMPG), there
was significant difference regarding frequency of atrial fibrillation (p≤0.05), left atrial size (p≤
0.05), mitral valve area andflow velocities (p≤0.05) in group-1 patients. Similarly, atrial fibrillation
was observed in 35(42.7%) patients out of which 20(83.3%) patients had thrombus in
left atrial appendage.
Conclusion: The frequency of left atrial thrombus formation increased in patients with rheumatic
mitral stenosis because of low left atrial appendage flow velocities, atrial fibrillation and
smaller mitral valve area.