A 6-week-old boy is brought to the emergency department due to poor feeding. The mother reports that the infant starts breastfeeding but after a few minutes begins sweating and grunting and stops nursing. He was born to a 38-year-old woman who declined prenatal testing and had an uncomplicated home vaginal birth. The infant's weight is

Question

A 6-week-old boy is brought to the emergency department due to poor feeding.  The mother reports that the infant starts breastfeeding but after a few minutes begins sweating and grunting and stops nursing.  He was born to a 38-year-old woman who declined prenatal testing and had an uncomplicated home vaginal birth.  The infant's weight is <5th percentile.  Vital signs show tachycardia.  Examination shows a round, dysmorphic face with upslanting palpebral fissures, a furrowed tongue, and abnormal palmar creases.  Auscultation reveals a fixed split S2 and a grade 2/6 systolic ejection murmur best heard at the left upper sternal border.  Bibasilar crackles are present.  Which of the following congenital heart defects is most likely present in this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d631_3abe_bc81_2141600549e5_MD0003_00 Complete atrioventricular septal defect (CAVSD) is the most common congenital heart defect in patients with Down syndrome. Failure of the endocardial cushions to merge results in both a ventricular septal defect (VSD) and an atrial septal defect (ASD). A common atrioventricular (AV) valve also occurs due to poor mitral and tricuspid valve development. Down syndrome In CAVSD, heart failure results from blood mixing between the chambers and severe AV valve regurgitation, leading to volume overload and excessive pulmonary blood flow. Diaphoresis and dyspnea with feeds and crackles typically manifest around age 6 weeks as pulmonary vascular resistance falls. Auscultation may reveal any of the following: Fixed split S2 due to delayed pulmonary valve closure from flow across the ASD Systolic ejection murmur from increased flow across the pulmonary valve due to left-to-right shunt across the ASD Holosystolic murmur of VSD that may be soft or absent if the defect is large Holosystolic apical murmur depending on the degree of AV valve regurgitation (Choice A) Coarctation of the aorta is associated with Turner syndrome and presents with diminished or absent lower-extremity pulses and upper-extremity hypertension. (Choice C) Symptomatic Ebstein anomaly presents with cyanosis and heart failure due to severe tricuspid regurgitation. Auscultation reveals a "triple or quadruple gallop" (widely split S1 and S2 plus a loud S3 and/or S4) and a holosystolic or early systolic murmur at the left lower sternal border. (Choice D) Patent ductus arteriosus presents with a continuous machine-like murmur. It is strongly associated with congenital rubella syndrome. (Choice E) Tetralogy of Fallot (TOF) presents with cyanosis, a single S2, and a harsh crescendo-decrescendo murmur caused by right ventricular outflow tract obstruction. TOF typically occurs sporadically; only 15% of patients with TOF have an associated condition (eg, Down or DiGeorge syndromes). CAVSD is more likely in this patient with Down syndrome who has a fixed split S2. Tetralogy of Fallot (Choices F) Transposition of the great arteries (TGA) is strongly associated with DiGeorge syndrome. TGA causes severe neonatal cyanosis and tachypnea, typically within the first 24 hours of life. A single S2 is present on auscultation, and a murmur may be absent unless there is a concomitant VSD. Transposition of the great arteries Educational objective: Complete atrioventricular septal defect is the most common heart defect in Down syndrome. Clinical features can include heart failure in early infancy, a fixed split S2, and a systolic ejection murmur due to increased pulmonary flow from the atrial septal defect. References: Cardiovascular abnormalities in Down syndrome: spectrum, management and survival over 22 years. (http://www.ncbi.nlm.nih.gov/pubmed/21835834)

A 6-Week-Old Boy Is Brought to the Emergency Department Due