Fig. 5
From: Long term respiratory morbidity in patients with vascular rings: a review
Maximal expiratory flow-volume curve in a patient with complete vascular ring (RAA with mirror image branching and LLA). Note the flattening of the proximal portion of the expiratory flow-curve due to the external compression/tracheomalacia that affects to expiratory flow rates in the large airways but not in the peripheral ones. FEV1 2.12 L (85%), FVC 3.00 L (102%), FEV1/FVC 83%, FEF25-75% 1.82 L/s (65%)