An unusual cause of dyspnea

Right-sided arcus aorta (RSAA) is a rare condition and usually asymptomatic. However, it may be symptomatic if it causes tracheal or esophageal compression.

The authors evaluated clinical and radiological features of seven patients with RSAA who had the diagnosis between May 2006 and May 2009.

The authors found that the incidence of RSAA was 0.16% in patients who had applied to their clinic. The age of patients ranged from 17 to 55 years. The male to female ratio was 6/1. Four patients were symptomatic due to RSAA. Most common symptoms were dyspnea during exercise, which is similar to exercise-induced asthma and dysphagia. Two patients were misdiagnosed as asthma. The flow-volume curves on spirometry of the patients showed intrathoracic upper airway obstruction. Thorax magnetic resonance imaging (MRI) revealed marked narrowing of the tracheal air column due to external compression of RSAA in three patients.

RSAA should be included in the differential diagnosis of asthma. Spirometry may help to suspect RSAA. Thorax computed tomography (CT) and/or MRI are the best imaging methods for the diagnosis of RSAA.