Mobile biatrial thrombus in a patient with mitral stenosis under heparin infusion.

A 58-year-old female patient with complaints of sudden presenting pain and pallor on her left foot was referred to our clinic for urgent embolectomy. On her cardiovascular examination there was an apical grade 2/6 systolic murmur and a grade 2/4 diastolic murmur. The presenting electrocardiography revealed atrial fibrillation with rapid ventricular response. She underwent emergent femoro-popliteal embolectomy. Transthoracic echocardiography showed a mobile 1.4 x 1.7-cm sized left atrial thrombus, mild mitral regurgitation and 9 mmHg mean gradient on mitral valve after embolectomy. Unfractioned (UF) heparin infusion was initiated immediately after surgery. After three days, the control transthoracic echocardiography revealed left atrial thrombus and also a large 'snake-like' thrombus waving in right atrium. The patient underwent biatrial thrombectomy and mitral valve replacement. When she became haemodynamically stable, a bilateral lower limb venous Doppler ultrasonographic study was performed. This study indicated a thrombus formation in the deep veins of the left leg. The origin of the right atrial thrombus was probably a snapped piece of thrombus from the calf deep-veins after the initiation of intravenous UF heparin. In summary, we have reported an extremely rare case of biatrial thrombus in a patient under UF heparin infusion.