[A case of left atrial giant thrombus which appeared in a short period]

We reported a case with left atrial giant thrombus (LAGT) which appeared over a period of six months. The patient was a 65-year-old woman who came to our hospital complaining of syncopal attack. Her electrocardiogram showed atrial fibrillation with very slow ventricular response, and there was cardiac arrest for 1500 ms, mitral stenosis and regurgitation, aortic and tricuspid regurgitations were recognized in the echocardiogram. By coronary angiography, 90% stenosis in the left circumflex artery (LCX) was found, and using transseptal left atrium heart catheterization, pressure gradient from the left atrium to the left ventricle was also measured. We diagnosed that her valvular diseases were mild. To protect her from unconsciousness and heart failure, a permanent pacemaker was implanted and PTCA for LCX lesion was performed. After six months, we found LAGT by echocardiography. It is very rare that LAGT is formed in a short period. We suggested that the changes of hemodynamics caused by transseptal left atrial catheterization or the permanent pacemaker implantation effected the formation of the LAGT.