BACKGROUND: Systemic thromboembolism is a known complication of rheumatic mitral stenosis (RMS) in sinus rhythm (SR). Left atrial appendage (LAA), the commonest site of thrombus formation is usually hypocontractile (inactive) in such patients. We aimed to study the prevalence of LAA inactivity (LAAI) in severe RMS and assess its independent predictors. METHODS: The study population consisted of 100 patients of severe RMS in sinus rhythm. Transthoracic and transesophageal echocardiography were done to assess LAA contractile function. Patients with LAA-peak emptying velocity <25 cm/sec were defined as having LAAI. RESULTS: The mean age of study subjects was 31.66±8.69 years and 56% were females. 73% patients had LAAI (Group A), while remaining 27% had normal LAA function (Group B). Mitral-valve area (MVA) and lateral annulus systolic velocity (Sa-wave) were significantly lower while mean pressure gradient across mitral valve (MGMV) and serum fibrinogen were significantly higher (all p-values <0.001) in group A patients. On multivariate regression analysis, MGMV (p<0.001), Sa-wave (p=0.02) and serum fibrinogen (p=0.005) were independent predictors of LAAI. Optimal cut-off values of MGMV, Sa-wave and serum fibrinogen for predicting LAAI were 11.5mmHg, 6.8cm/sec and 300mg/dL respectively.67(90.55%) patients in group A compared to 13(48.1%) in group B had LA/LAA smoke. LAAI was the only independent predictor of left atrium (LA)/LAA smoke and associated thrombus. CONCLUSION: There is high prevalence of LAAI in patients of severe MS in SR. MGMV, Sa-wave and serum fibrinogen levels are independent predictors of LAAI. LAAI is an independent predictor of LA/LAA smoke and associated thrombus.

Aim: The aim of this study was to assess the left atrial (LA) function in severe rheumatic mitral stenosis (MS) patients using two-dimensional speckle tracking echocardiography (STE) and its correlation with clinical symptoms and echocardiography parameters. Methods: A total of 120 subjects (80 patients with isolated severe MS [mitral valve area (MVA) ≤1.5 cm2] in sinus rhythm and 40 healthy controls) underwent comprehensive echocardiography including STE for assessment of LA strain [reservoir strain (LASr), conduit strain (LAScd) and contractile strain (LASct)]. Results: The mean MVA in cases was 0.93 ± 0.21 cm2. The mean values of LASr (14.73 ± 8.59%), LAScd (-7.61 ± 4.47%) and LASct (-7.16 ± 5.15%) among cases were significantly less (p< 0.001) when compared to controls where the values were 44.11 ± 10.44%, -32.45 ± 7.63%, -11.85 ± 6.77% respectively. Thus the compensatory LA contractile function was also compromised. The New York Heart Association (NYHA) class III, II and I dyspnea was present in 37 (46.25%), 38 (47.5%) and 5 (6.25%) subjects respectively. All the three LA strain parameters showed a trend towards decline with increase in severity of MS, increase in LA size, increase in mean and peak diastolic transmitral gradients and with higher NYHA functional class. Conclusion: Left atrial dysfunction is common in severe rheumatic MS as suggested by severely reduced LA reservoir, conduit and contractile strain. Early and timely intervention in these patients irrespective of NYHA functional class is advocated as it may likely improve the LA function and avoid clinical deterioration.