Transoesophageal echocardiographic detection and surveillance of left atrial thrombosis.

Out of 1 141 successive transoesophageal echocardiographic studies performe d prospectively between 01/05/1993 and 31/12/1995, 26 cases of left atrial thrombosis were observed (2.2%); 5 were in the left atrium (20%), 19 in the left atrial appendage (73%) and the thrombi were in both atrium and left a trial appendage in 2 cases (7%). The 26 patients included 15 women and 11 m en, with an average age of 69 +/- 16 years (range 25-89 years); 22 patients (84%) had permanent atrial fibrillation and 4 were in sinus rhythm. Only 5 of the patients were on oral anticoagulant therapy. All had underlying cardiac disease : 11 mitral valve diseases; 10 dilated c ardiomyopathies; 2 hypertrophic cardiomyopathies; 3 other cardiac diseases. The indication for transoesophageal echocardiography was systemic embolism in 13 cases (50%); before D.C. cardioversion in 19 cases (38%) and before percutaneous mitral valvuloplasty in 3 cases. The thrombus was adherent in 18 cases (69%) and mobile in 8 cases (31%). Sp ontaneous contrast was observed in 23 cases (88%). Intravenous heparin was given as soon as the diagnosis was made. In 4 patients, thrombectomy was in dicated in View of the threatening nature of the thrombus and/or the necess ity for associated valve replacement. In 22 patients, heparin was relayed by oral anticoagulants on the 10th day of treatment. Control transoesophageal echocardiography was not performed b ecause of the patient's refusal or poor general condition. The other 15 pat ients were reexamined 1 to 5 times between the 4th day and 12th month : a r egression was observed in 13 cases (86%) which was complete in 11 and parti al in 2 cases. No cases of embolism occurred during follow-up but six patie nts died : 1 of the operated cases and 5 of the patients treated medically (3 cardiac failures and 2 cerebral haemorrhages). The authors conclude that left atrial thrombosis is rare in the absence of classical embolic cardiac disease. With the exception of the surgical indic ation of a life-threatening thrombus and/or associated surgical mitral valv e disease, anticoagulant therapy results in complete or partial regression of the thrombus visualised by transoesophageal echocardiography which is es sential for follow-up. The prognosis depends on the severity of the underly ing heart disease.