In a Down's syndrome patient posted for surgery, the necessary preoperative investigation to be done is -

Description:Congenital hea disease affects ~40%. In paicular, defects affecting the endocardial cushion are common: * atrioventricular septal defect (AVSD): considered the commonest cardiac defect associated with Down syndrome * ostium primum atrial septal defect (ASD) * ventricular septal defect (VSD)