The effect of transient balloon occlusion of the mitral valve on left atrial appendage blood flow velocity and spontaneous echo contrast

Abstract

SummaryBackground: Spontaneous echo contrast (SEC) is a phenomenon that is commonly seen in areas of blood stasis. It is a slowly moving, cloud-like swirling pattern of "smoke" or increased echogenicity recorded on echocardiography. SEC is commonly seen in the left atrium of patients with mitral stenosis or atrial fibrillation. The prescence of SEC has been shown to be a marker of increased thromboembolic risk.Hypothesis: By using transesophageal echocardiography during percutaneous balloon mitral valvotomy (PBMV), the study investigated the relationship between SEC and varying left atrial appendage (LAA) blood flow velocity in the human heart.Methods: Thrty-five patients with rheumatic mitral stenosis underwent percutaneous balloon mitral valvotomy withintraoperative transesophageal echocardiography monitoring. We alternatively measured LAA velocities and observed the left atrium for various grades of SEC (0 = none to 4 = severe) before and after each balloon inflation.Results: Left atrial appendage maximal ejection velocity was reduced from 35 & 14 to 6 2 2 m m / s at peak balloon inflation and increased to 40 k 16 m m / s after balloon deflation. In comparison with the values before balloon inflation and after balloon deflation, LAA velocities were significantly lower

Left Atrial Appendage (LAA) Function by Transesophageal Echocardiography before and after Percutaneous Balloon Mitral Valvuloplasty (PBMV)- A Comparative Study

“…Upon balloon deflation, LAA blood flow velocity increases again, resulting in the reduction or disappearance of SEC within the same time interval and LAA emptying and filling velocities have increased after the procedure. [23] Basal and postprocedure LAA velocities in patients with atrial fibrillation were found to be lower when compared with velocities in those with sinus rhythm. [23] In the same study at peak balloon inflation, LAA velocities were significantly lower and SEC was significantly higher in a group with atrial fibrillation than in a group with sinus rhythm.…”

“…[23] Basal and postprocedure LAA velocities in patients with atrial fibrillation were found to be lower when compared with velocities in those with sinus rhythm. [23] In the same study at peak balloon inflation, LAA velocities were significantly lower and SEC was significantly higher in a group with atrial fibrillation than in a group with sinus rhythm. Thus, regular contraction in sinus rhythm may decrease SEC formation.…”

“…The effect of PBMV on LAA functions has been investigated in various studies. Wang et al, [23] showed the changes in LAA flow velocities and in SEC at the time of transient occlusion of the mitral valve by balloon inflation. LAA blood flow velocity reduces substantially even to the point of complete stasis resulting in acute enhancement of SEC to the highest grade almost simultaneously during the mechanical obstruction of blood flow by balloon inflation at the mitral valve.…”

Improved Detection of Spontaneous Echo Contrast in the Aorta with Tissue Doppler Imaging

“…Spontaneous echo contrast within the cardiac chambers or vessels is associated with increased risk of thromboembolism. Left atrial spontaneous echo correlates with low emptying velocity in the left atrial appendage (depressed atrial function) and enlarged left atrium 1,2 . In dilated and akinetic left ventricles SEC may be a precursor of thrombus formation 3,4 …”

“…Left atrial spontaneous echo correlates with low emptying velocity in the left atrial appendage (depressed atrial function) and enlarged left atrium. 1,2 In dilated and akinetic left ventricles SEC may be a precursor of thrombus formation. 3,4 Spontaneous echo contrast in the thoracic aorta has been associated with significant aortic atherosclerosis, dilated or aneurysmatic aortas, older age, and low blood velocity.…”