Left Atrial Spontaneous Echo Contrast in Mitral Stenosis: Before and Immediately After Percutaneous Mitral Valvuloplasty

ABSTRACT

BACKGROUND: Dynamic echoes in the left atrium, spontaneous echo contrast(SEC), represents a marker for thromboembolic risk in patients(pts) with mitral stenosis(MS). The aims of this study were to determine the factors associated with SEC in pts with MS and to observe the immediate effect of percutaneous mitral, valvuloplasty(PMV) on SEC. METHODS: Biplane transesophageal echocardiography(TEE) including Doppler measurement of left atrial appendage flow was performed before and immediately after PMV in 50 pts with MS[32 in normal sinus rhythm(NSR) and 18 in atrial fibrillation(AF)]. Hemodynamic data of left atrial pressure, transmitral pressure gradient, mitral valve area by Gorlin's method(MVA) and cardiac output(CO) by thermodilution method were obtained before and after successful PMV. RESULTS: Before PMV(MVA of 0.9±0.3cm2), SEC was observed in 60%(30/50) of tight MS (13/32 in NSR, 17/18 in AF). The presence of AF(p=0.001), increased left atrial dimension(p=0.001), decreased appendage peak positive velocity(APPV, p=0.03), decreased MVA(p=0.01) and reduced CO(p=0.001) were positive predictive factors for SEC AF was the most powerful factor among them. In pts with NSR, MVA(p=0.01) was the only factor for SEC before PMV. After successful PMV(MVA of 2.0±0.4cm2) SEC was still observed in 6 pts(12%) with AF. AF(p=0.001), increased left atrial dimension(p=0.06) and decreased APPV(p=0.001) were favorable factors for persistence of SEC after PMV, but hemodynamic indices were not associated with SEC after PMV. New development of mitral regurgitation after PMV was the only predictive factor for disappearance of SEC(p=0.04). In pts with NSR, PMV promptly normalized the APPV with disappearance of SEC. CONCLUSION: In pts with tight MS, different factors may be associated with SEC according to the rhythm. PMV is an effective method to abolish SEC with hemodynamic improvement. Despite the similar MVA and hemodynamic indices, possible preventive effect of thromboembolism after PMV nay be more prominent in pts with NSR compared to those with AF.