Echocardiographic predictors of coarctation of the aorta

Abstract

Echocardiography is the main diagnostic modality of coarctation of the aorta especially in infants less than 3 months. Sometimes it is difficult to diagnose coarctation of the aorta either because of poor echo window or because of the presence of a large PDA. Failure or delay in the diagnosis of coarctation will lead to morbidity as well as mortality. The objectives of our study were to look for echocardiographic predictors of coarctation of the aorta. During the period from September 2010 to July 2011 echocardiographic measurements were performed for 67 normal infants referred for echocardiography. This was compared with 37 patients with proved coarctation either by surgery or cath. Echocardiographic measurements performed in both groups include aortic annulus, ascending aorta diameter, proximal transverse arch diameter, distal transverse arch diameter, aortic isthmus diameter, distance between aortic arch branches. Aortic valve anatomy , associated findings as well as surgical and cath diagnosis were reviewed. The ratio between the transverse arch and ascending aorta as well as between transverse arch and the distance between aortic arch branches were calculated. We compared both groups using SPSS statistical software. Measurements were done online as well as offline. During the study period 67 normal infants and 37 infants with coarctation were reviewed. The age group were from one day to one year and the mean weight were 4.48 ± 1.67 and 3.8 ± 2.19 kg for the normal and abnormal groups, respectively. There were no statistical difference between the two groups regarding the age weight as well as the gender. There were statistical difference in the echocardiographic measurements between the two groups regarding the transverse arch diameter with a smaller diameter in the CoA group (3.89 ± 1.17 vs 5.8 ± 1.05 mm, P value 0.0001). The ratio between the transverse arch and the ascending aorta was smaller in patients with CoA (0.55 ± 0.16 vs 0.73 ± 0.16, P value 0.0001). The distance between the left common carotid and the left subclavian arteries was longer in patients with CoA compared to those with normal arch (4.76 ± 2.37 mm vs 2.85 ± 1.59 mm, P value 0.0012). The ratio between the distance between the left common carotid and the left subclavian arteries to that of the transverse aortic arch diameter was higher in patients with Co (1.3311 ± 0.71 vs 0.54 ± 0.29, P value 0.0001). Bicuspid aortic valve was found in 57% of patients with CoA compared to only 6.5% of patients without coarctation (P value 0.0001). Echocardiographic predictors of coarctation of the aorta include the presence of bicuspid aortic valve, hypoplasia of the transverse arch, smaller ratio between the transverse arch and the ascending aorta and high ratio between the distance between aortic arch branches and transverse aortic arch.