ABSTRACT
To determine the frequency of various congenital cardiac defects associated with atrial heterotaxy and the difference between spectrum of cardiac defects in right atrial isomerism [RAI] and left atrial isomerism [LAI] in these patients. Cross-sectional observational study. Department of Cardiology, The Children's Hospital and Institute of Child Health, Lahore, from July 2006 to June 2011. All children presenting to the hospital with suspected congenital heart defect were included in the study. Echocardiography based sequential segmental analysis was used, taking atrial symmetry, interrupted inferior vena cava [IVC] and juxtaposed aorta to IVC relation into account for identifying atrial heterotaxy. Various segmental defects were noted for RAI and LAI. Children had atrial heterotaxy [M:F; 1.7:1] with 61.6% [n=82] having LAI. Most common lesions associated with RAI included complete atrioventricular [AV] septal defect [n=48, 94.1%], single AV valve [n=45, 88.2%] and pulmonary outflow tract obstruction [n=41, 80.4%]. LAI was associated with ventricular septal defect [n=68, 82.9%], atrial septal defect [n=63, 76.8%, mostly secundum variety], and miscellaneous left sided obstructive lesions. Atrial heterotaxy encompasses a wide spectrum of congenital cardiac defects. The frequency of various defects associated with RAI or LAI in local South Asian population of Lahore, Pakistan is similar to those as reported in the Western literature