The physical examination of the term newborn’s cardiovascular system is reviewed detailing the normal and abnormal variants that can be found within the first few days after birth. The authors discuss the pathophysiologic changes that occur in the presence of congenital heart disease and how these changes affect the clinical presentation. The major common cardiac defects are described and discussed. Pulse oximetry screening is reviewed in detail indicating its value in the early detection of most cases of critical congenital heart disease. Finally, the reader is given several suggestions on diagnosis, stabilization, and when to refer to specialists.
Key points
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Although congenital heart defects can be diagnosed using fetal cardiac ultrasonography, some defects can be challenging to identify.
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Even with a careful complete physical examination, some infants seem normal and are discharged home undiagnosed.
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The persistence of fetal channels can mask the presence of critical congenital heart disease, and the rather short postpartum hospital stay contributes to the diagnostic challenges.
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It is essential for the examiner to use all physical examination skills, including inspection, palpation, and auscultation, and to perform more than one physical assessment before discharge or shortly thereafter.
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The recent introduction of Pulse Oximetry Screening has been an extremely helpful adjuvant in assisting with the diagnosis of CCHD.
Cardiac evaluation of the newborn
The approach to the cardiac evaluation of a newborn can be challenging. As a result, many pediatricians report that they often feel uncomfortable when it comes to differentiating the normal from the abnormal state with regard to a newborn’s cardiovascular examination. It is the authors’ goal for this article to provide the reader with the background knowledge that will make the cardiac evaluation of newborns less intimidating and assist the general pediatrician in understanding, detecting, and treating a newborn with congenital heart disease (CHD).
CHD is the most common congenital disorder in newborns, occurring in approximately 8 out of 1000 live births, and is responsible for almost 30% of infant deaths related to birth defects. Of those children with CHD, about 1 in 4 (25%) babies born with a heart defect will have critical CHD (CCHD), defined as needing intervention within the first year of life.
Although CHD can be diagnosed using fetal cardiac ultrasonography, some defects can be challenging to identify. Similarly, even with a careful complete physical examination, some infants seem normal and are discharged home undiagnosed. The persistence of fetal channels can mask the presence of CCHD, and the rather short postpartum hospital stay contributes to the diagnostic challenges. Thus it is essential for the examiner to use all physical examination skills, including inspection, palpation, and auscultation, and to perform more than one physical assessment before discharge or shortly thereafter. The recent introduction of pulse oximetry screening (POS) has been an extremely helpful adjuvant in assisting with the diagnosis of CCHD before signs of decompensation occur.
Initial Evaluation
The first step in the assessment of the newborn infant’s cardiovascular system is a careful review for conditions that are associated with an increased risk of CHD ( Table 1 ). The presence of any of these factors should raise the index of suspicion, but a complete physical examination should be performed regardless.
| Maternal | Perinatal |
|---|---|
| Diabetes | TORCH infection |
| Obesity | Premature delivery <37 wk |
| Hypertension | Genetic/chromosomal disorders |
| Systemic lupus erythematosus | VACTERL |
| Epilepsy | Omphalocele |
| Influenza or flulike symptoms | Congenital diaphragmatic hernia |
| First-trimester smoking | |
| Maternal thyroid conditions | |
| Maternal CHD | |
| Maternal alcohol/medication use | |
| Multifetal pregnancy |
Inspection and Palpation of the Skin and Mucous Membranes
The color of the skin and briskness of capillary refill can be indicators of the adequacy of oxygenation and cardiac output. The mucous membranes of a normal newborn should be pink. This is usually checked by looking at the tongue and lips. When light pressure is applied to the skin or nail beds, normal color should return within 3 to 4 seconds after the pressure is released (capillary refill time).
Acrocyanosis is usually described as cyanosis of the distal portions of the extremities but can be seen around the mouth and in the nail beds. However, the mucous membranes generally remain pink. Acrocyanosis is common in newborns and is normal. It can be caused by vasomotor instability, vasoconstriction caused by cold, or polycythemia. The degree of acrocyanosis can be related to the level of hematocrit and is most obvious with a central hematocrit of 65% or greater. Acrocyanosis is increased with crying and fades when sleeping. It is usually uniformly distributed in the arms and legs but may have an asymmetric pattern being more obvious in certain extremities. However, distinct differences in appearance between upper and lower parts of the body should raise concern and be investigated. Determination of a central hematocrit and peripheral hemoglobin saturation can be helpful. With acrocyanosis caused by polycythemia, the hematocrit will be elevated and hemoglobin saturation will be 90% to 95%. A normal hematocrit and/or abnormal hemoglobin saturation should prompt further investigation.
Central cyanosis is always abnormal. This condition may be caused by primary pulmonary disease or CCHD, which restricts pulmonary blood flow (PBF) ( Box 1 ). Cyanosis caused by pulmonary disease is often responsive to the administration of oxygen. Central cyanosis caused by CCHD does not change significantly when patients are placed in an oxygen-enriched environment.
