[Rhabdomyoma of the left atrium. A rare case of mitral valve congenital obstruction simulating hypoplastic left heart syndrome. Echocardiographic diagnosis].

The AA. describe the clinical, surgical and pathological features of a 13-days old infant with multiple cardiac rhabdomyomas diagnosed by two-dimensional echocardiography (2DE). The clinical picture simulated hypoplastic left heart syndrome (HLHS). 2DE showed a well developed left heart. The apical four chamber view disclosed a mass of echoes between the left atrium and ventricle, across the mitral valve. Another little mass of echoes was attached to the left surface of the ventricular septum. The other cardiac chambers and the great arteries were normal. These multiple intracardiac masses were interpreted as rhabdomyomas. The infant underwent an operation at the age of 21 days because of mitral valve obstruction and CHF. At surgery, a left atrial rhabdomyoma was found, that severely obstructed the mitral valve orifice. Although after resecting the tumour we felt that the obstruction was adequately relieved, the little patient died of pulmonary oedema one hour after surgery. At autopsy all the previously detected myomas were confirmed and a small additional one was discovered within the crista supraventricularis. Unexpectedly, the chordae tendineae of the mitral valve were extremely short. This anomaly, masked preoperatively by the rhabdomyoma, was probably the cause of the fatal postoperative mitral regurgitation.