Résumé : A 72 year old man was admitted with severe dyspnoea. Ten days before he had had intense thoracic pain with loss of consciousness that was followed by increased dyspnoea. A continuous murmur was heard in the precordial and the left infrascapular regions. Lung auscultation showed stasis over the lower half of both lungs. Transthoracic echocardiography showed a bicuspid aortic valve and a dissection of the proximal aorta, which was considerably enlarged. Transoesophageal echocardiography confirmed dissection of the proximal aorta and showed a communication from the false lumen of the aortic dissection to the left atrium; and colour flow Doppler showed a continuous shunt to the left atrium. After transoesophageal echocardiography the patient had emergency surgical repair, which was successful. He had no complications in the postoperative period.