The most common presentation of double aortic arch in infants is ?: (A) Dysphagia, (B) Tracheal compression symptoms, (C) Positional hyperemia with right upper arm oedema, (D) Bleeding
Answer is B. Double aortic arch 

Congenital abnormalities of the aortic arch and its major branches result in the formation of vascular rings around the trachea and esophagus with varying degrees of compression.
The most common cause is a double aortic arch.
Double aortic arch results when right dorsal aorta persists distal to the origin of the right 7th cervical intersegmental artery.
Clinical manifestations of double aortic arch are :-


The age and type of presentation depend on the tightness of the ring. About 75% with a double aortic arch, 55% with a right aortic arch & abberant left subclavian artery and 95% with compression by an abberant innominate artery present in infancy with repiratory symptoms, including stridor, persistent cough and frequent respiratory illnesses.
If the vascular ring produces compression of the trachea and esophagus, symptoms are frequently present during infancy.
Chronic wheezing is exacerbated by crying, feeding, and flexion of the neck.
Extension of the neck tends to relieve the noisy respiration.
Vomiting may also be a component. Affected infants may have a brassy cough, pneumonia, or sudden death from aspiration.
Others can present in later childhood or even as teenagers or young adults with a history of respiratory symptoms that mimic asthma or exercise-induced asthma.
Some are diagnosed later in life after being asymptomatic during entire childhood.
The later the presentation, the more chances of gastrointestinal symptoms being the presenting symptoms. Symptoms like dysphagia, choking vomiting may be seen.