Backround: Spontaneous echo contrast (SEC) is an echocardiographic
finding particularly found in left atrium of patients with mitral
stenosis (MS) and known as a risk factor for stroke. However, its
pathophysiology is not fully understood. Methods: Forty-eight patients
with MS scheduled for percutaneous mitral valvuloplasty were included in
the study. Blood samples were taken from the aorta and left atrium (LA)
during the procedure. Whole blood viscosity (WBV), plasma viscosity (PV)
and peripheral blood smears were obtained and analysed separately from
these sites. All participants underwent transthoracic and
transesophageal echocardiography prior to the procedure Results: Severe
SEC (grade 3-4) was found in 23 patients, remaining 25 patients had mild
to moderate SEC (grade 0-1-2). Patients with severe SEC had increased LA
diameter, area and PV. However, ejection fraction, left atrial appendage
(LAA) filling and emptying velocities, LAA lateral wall late systolic
velocity, LAA fractional area change and pulmonary vein (PVe) systolic
velocity were found to be significantly reduced in patients with severe
SEC compared to mild to moderate SEC. On multiple linear regression
analysis, atrial fibrillation, left atrium PV and diameter were strongly
correlated with SEC grade (Respectively p=0,011, p=0,013, p=0,030).
Conclusion: We have shown that AF, systolic dysfunction of LAA and left
ventricule, reduced PVe flow velocity, increased LA dimensions and left
atrial PV were related with the severity of SEC in patients with mitral
stenosis. We demonstrated the relationship between the increase left
atrial PV and SEC in addition to impaired hemodynamic determinants in
patients with mitral stenosis.