[Dyspnea of effort associated with a congenital aortic malformation]

We report the case of a young woman presenting with dyspnoea of effort. Her records noted that correction of a double aortic arch had been performed in the neonatal period. At rest her flow/volume loop showed a moderate reduction of peak flow without an expiratory plateau. Exercise capacity was limited by sudden onset, during the last 2 stages of the test, of inspiratory dyspnea and tachypnea. During recovery there was no evidence of bronchospasm.

With this picture we suspected upper airway obstruction and bronchoscopy revealed tracheal compression to 50% of normal. CT scan with 3 dimensional reconstruction showed the trachea compressed between 2 aortic branches. In order to confirm that the tracheal compression increased during exercise we induced sympathetic stimulation by a "handgrip" test that reproduced the inspiratory dyspnea and lead to a reduction in inspiratory flows.

We have thus demonstrated that the increase in tracheal compression leading to limitation of airflow on exercise was due to an increase in aortic pressure and not to an increase in ventilatory flows.