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Paper text:
the aortic origin of the right or left pulmonary artery is an infrequent cardiac anomaly whose incidence is < 1% of all the congenital cardiac malformations .
the right pulmonary artery ( rpa ) arises directly from the ascending aorta in 70 - 80% cases , and is associated with a patent ductus arteriosus ( pda ) in 75% of cases.12 it is frequently associated with other cardiac malformations and rarely presents as an isolated anomaly as in our case.3 the clinical setting is characterized by increased pulmonary blood flow , congestive heart failure , and cyanosis when the pulmonary pressure and vascular resistance are too elevated .
early surgical intervention is recommended in all patients because of the risk of rapid development of irreversible pulmonary vascular disease .
here , we report a rare case of an infant with aortic origin of a pulmonary artery which was diagnosed by echocardiography .
a 45 day old female infant , weighing 3.2 kg was referred for the assessment of a heart murmur . a history of tachypnoea was present .
she was the offspring of non - consanguinous parentage and was born by normal vaginal delivery .
this baby 's general physical examination was unremarkable with no evidence of pallor , cyanosis or dysmorphism .
cardiac auscultation revealed a normal first heart sound and a loud pulmonary component of the second heart sound along with a grade 3 ejection systolic murmur audible best at the left upper parasternal area .
electrocardiography showed sinus rhythm with normal qrs axis and peaked p waves in the limb leads and right precordial leads .
on echocardiography , parasternal short axis view ( fig1 ) and suprasternal view ( fig 2 ) clearly showed right pulmonary artery arising from the ascending aorta and left pulmonary artery from the main pulmonary artery .
parasternal shortaxis view showing the anomalous right pulmonary artery arising from the aorta and the normal left pulmonary branch from the main pulmonary artery .
the aortic origin of a pulmonary artery is a rare congenital anomaly in which one pulmonary artery branch , usually the right , arises from the ascending aorta just above the aortic sinuses , whereas the main pulmonary artery and the other pulmonary branch arise in their normal position .
tetralogy of fallot , patent ductus arteriosus , right aortic arch and aortopulmonary defect are common associations in anomalous origin of right pulmonary artery ( aopa).45 this type of cardiac malformation was described first by fraentzel in 1868 .
nakamura y et al reported the two forms : a proximal one , the aopa originates from the ascending aorta close to the valvar plane ; and a distal one in which the aopa arises via a patent ductus arteriosus.6 tsutsumi y et al on the other hand described one form in which the origin site is close to the innominate artery or in extreme cases , the right aopa arising from the innominate artery.7 congestive heart failure develops early in infancy , with respiratory distress and poor weight gain .
cyanosis may be present due to right to left shunting through the pda or from the persistence of the foramen ovale in the presence of a high pulmonary resistance .
the development of pulmonary vascular disease is attributed to several mechanisms such as increased pulmonary blood flow , circulating vasoconstrictor substances , neurogenic crossover from the unprotected lung , and left ventricular failure.3 a continuous murmur and bounding pulses may be present .
the echocardiography is usually sufficient for an accurate diagnosis of aopa from aorta but the angiogram and 3-dimensional mr angiography may confirm it.45 the images obtained from parasternal short axis and apical 4-chamber views allow a precise diagnosis of aopa .
echocardiography demonstrates the presence of two concordant ventricular outflow tracts , the absence of the usual main pulmonary artery trunk ( mpat ) bifurcation pattern and the right or left pulmonary artery arising directly from the aorta with the mpat continuing with the contralateral pulmonary artery branch .
all the echocardiographic characteristic features of aopa were present in our case without any other cardiac malformations .
surgical intervention is recommended as early in life as possible.89 different techniques have been successfully employed to reimplant the aopa to the mpat such as direct implantation , end - to - end anastomosis with a synthetic graft , homograft patch , and 
the banding of the anomalous pulmonary artery and pda ligation have been described as a palliative alternative in special cases such as premature infants with very low weight.911 in conclusion , isolated aortic origin of the right pulmonary artery without any other cardiac malformation is in itself a rare cardiac anomaly but can be diagnosed with transthoracic echocardiography by an alert echocardiographer .
the aortic origin of right or left branch pulmonary artery is a rare cardiac anomaly in which the right pulmonary artery usually arises from the ascending aorta just above the aortic sinuses , whereas the main pulmonary artery and the other pulmonary branch arise in their normal position . 
 we report a rare case of isolated origin of right pulmonary artery from the ascending aorta .