[Spontaneous course of myxoma of the left atrium].

Little is known about the natural history of left intra-atrial myxomas. We report 3 cases of that disease where successive echocardiographic examinations provided figures of 11, 12 and 14 months respectively for the formation of the tumour in the left atrium. Echocardiography is perfectly reliable for the diagnosis of myxoma. False-negative results are rare and usually due to very small myxomas being beyond the resolution potential of the instrument; this seems to have been the case in 2 of our 3 patients. Two data, however, remain unknown: the beginning of formation and the rapidity of tumoral growth. These 3 cases raise the problem of repeat echocardiography some time after a cerebral accident of suspected embolic origin, when the initial examination is negative.