**7. Heart failure in the newborn infant**

The clinical picture of CHF in the neonate may simulate another disorder such as meningitis, sepsis, pneumonia, or bronchiolitis. Tachypnea, tachycardia, pulmonary crackles or rhonchi, hepatomegaly, and weak peripheral pulses are common presenting signs. Heart murmur is either faint or absent. Cardiomegaly on chest x-ray film is always present, with or without increased PVMs or pulmonary edema. Causes of CHF in the neonate are listed in Table 2.

### **a. Structural heart defects**

#### At birth

240 Congenital Heart Disease – Selected Aspects

independent of the level of the PVR.

infancy or in childhood.

in sepsis, circulatory shock, or severe hypoxemia.

only occasionally in those with cyanotic heart disease.

as well as in making a specific diagnosis.

differential Po2 levels.

e. An ECG should be obtained if a cardiac origin of cyanosis is suspected.

component.

measures.

a. Heart murmurs of stenotic lesions (e.g., aortal stenosis (AS), pulmonary stenosis (PS)) are audible immediately after birth and persist, because they are

b. Heart murmurs of L-R shunt lesions, especially those of a large VSD, may appear later, when the PVR decreases. The murmur of ASD appears late in

c. The continuous murmur of a large PDA may not appear for 2 to 3 weeks. Instead, it is a crescendo systolic murmur with a slight or no diastolic

Even in the absence of a murmur, a newborn infant may have a serious heart defect that requires immediate attention, e.g., severe cyanotic heart disease such as TGA or pulmonary atresia with a closing PDA. Infants who are in severe CHF may not have a loud murmur until the myocardial function is improved with anticongestive

b. Chest x-ray films may reveal pulmonary causes of cyanosis and urgency of the problem.They will also hint at the presence and the type of any cardiac defects. c. Arterial blood gases on room air will confirm or rule out central cyanosis. Elevated Pco2 suggests pulmonary or central nervous system (CNS) problems. Low pH may be seen

d. Hyperoxia test is one method of distinguishing cyanotic congenital heart disease from pulmonary disease. Neonates with cyanotic congenital heart disease usually do not have significantly raised arterial Pao2 during administration of 100% oxygen. If the Pao2 rises above 150 mmHg during 100% oxygen administration, an intracardiac shunt can usually be excluded, although the Pao2 of some patients with cyanotic congenital heart lesions may be transiently increased to greater than 150 mm Hg because of intracardiac streaming patterns. The Pao2 in patiens with pulmonary disease generally increases significantly as ventilation – perfusion inequalities are overcome by oxygen administration. In infants with a CNS disorder, the Pao2 completely normalizes during artificial ventilation. Hypoxia in many heart lesions is profound and constant, whereas in respiratory disorders and in primary hypertension of the neonate (PPHN), arterial oxygen tension is not as low and often varies with time or changes in ventilator management. Hyperventilation may improve the hypoxia in neonates with PPHN and

f. Two-dimensional echocardiography is the definitive noninvasive test to determine the presence of congenital heart disease. The information obtained is essential in avoiding unnecessary cardiac catheterization and angiography in the absence of a cardiac defect,

g. Umbilical artery line: A Po2 value in a preductal artery ( such as right radial artery) higher than that in a postductal artery (umbilical artery line) by 10 to 15 mm Hg suggests an R-L shunt through a PDA. Such a differential Po2 level may result from persistent pulmonary hypertension of the newborn (PPHN), critical AS, interrupted aortic arch, or coarctation of the aorta. An echo study will clarify the cause of the

h. Cardiology consultation is called for if a cardiac origin of cyanosis is suspected.

Hypoplastic left heart syndrome (HLHS)

Severe tricuspid or pulmonary regurgitation

Large systemic AV fistula

Week 1

TGA

Large PDA in premature infant

Total anomalous pulmonary venous return (TAPVR) below diaphragm
