18: 2-week-old male with poor feeding

Question 1

Weight Loss in the Newborn

Answer 1

Newborns almost always lose some weight in the first few days after birth. Most will lose between 5 and 10% of their birth weight, and will be back to birth weight by 10-14 days of age.

Question 2

Feeding Patterns of Young Infants

Answer 2

Young infants who are breastfeeding usually nurse for 10-30 mins a time, as often as every 1-2 hours. Bottle-fed infants will often take more per feed and thus feed a little less often.

Question 3

Grading of Murmur Intensity

Answer 3

I-Faint and easily missed
II-Obvious
III-Loud
IV-Associated with a thrill
(Any murmur that is grade III, or is associated with a thrill (grade IV), is likely to be pathologic, and probably should be evaluated by a cardiologist.)

Question 4

Hepatomegaly in Infancy

Answer 4

fairly consistent finding in children with CHF. Decreased renal blood flow, via activation of the renin-angiotensin system, leads to fluid retention, systemic venous congestion, and hepatomegaly

Question 5

classic findings of CHF in an infant a few weeks after birth are

Answer 5

• -dyspnea with feedings
• -diaphoresis
• -poor growth
• -an active precordium
• -hepatomegaly

Question 6

If the answer to any of these questions is “no,” the murmur should not be considered innocent.

Answer 6

Is the child otherwise well?
Is the precordial activity normal?
Is the second heart sound normally split?
Is the murmur less than or equal to grade II/VI? Is the oxygen saturation normal?

Question 7

Atrial septal defect (ASD)

Answer 7

• -Often first detected at 3-5 years of age.
• -The pathognomonic physical finding of an ASD is a widely split, fixed S2, which is a subtle physical finding and difficult to detect on a potentially uncooperative infant with a higher resting HR.
• -Listening for wide splitting of the second heart sound is the most helpful way to distinguish an ASD from an innocent murmur.

Question 8

Coarctation of the aorta

Answer 8

• -Can present in infancy or at any age beyond because it tends to be a progressive problem, gradually getting more severe over a period of years.
• -Coarctation presents with a murmur, hypertension in the upper extremities, and a discrepancy between the upper and lower extremity blood pressures.

Question 9

Bicuspid aortic valve

Answer 9

• This is a common heart abnormality.
• If the bicuspid valve is not stenotic or regurgitant, then there will be no murmur.
• The PE finding of a bicuspid aortic valve is an early systolic click made by the abnormal valve when it opens (occurring shortly after the first heart sound, signifying the end of isovolumic contraction when the aortic valve opens to allow left ventricular outflow). This is a subtle exam finding that is often not heard in infants with higher HR, and is commonly not detected until later in childhood (if not adolescence or even adulthood).

Question 10

VSD

Answer 10

• Holosystolic starting with S1

- Characterized as somewhat blowing

Question 11

ASD

Answer 11

• Widely split S2 (hallmark heart sound of an ASD)

- Systolic murmur due to increased flow across a normal pulmonic valve

Question 12

Aortic stenosis

Answer 12

In a patient with aortic stenosis and aortic insufficiency (AI) there is a systolic ejection murmur followed by an early diastolic murmur of AI.

Question 13

Pulmonic stenosis

Answer 13

• Prominent systolic ejection click just after S1

- Harsh systolic ejection murmur

Question 14

PDA

Answer 14

The murmur is continuous, but a bit louder in systole.

Question 15

Innocent murmur

Answer 15

• Vibratory and low-pitched (its vibratory quality is the most characteristic feature of an innocent murmur)
• Heard best at the left lower sternal border

Question 16

Heart defects that present with a murmur and signs of CHF in infancy:

Answer 16

• -VSD
• -Severe aortic stenosis
• -Coarctation of the aorta
• -Large patent ductus arteriosus

Question 17

VSDs occur due to either

Answer 17

a lack of tissue (such as an endocardial cushion defect resulting in an inlet VSD) –OR– a lack of fusion (lack of fusion of the embryologic components at the membranous septum, resulting in a “peri” membranous defect).

Question 18

VSD CP

Answer 18

• Murmur and clinical signs usually are not present in the newborn nursery but are noted from several days to weeks of age.
• Age of presentation and symptoms are related to the magnitude of the left-to-right shunt, which is determined by the size of the defect and the pulmonary vascular resistance.
• Large defects often present with CHF as pulmonary resistance falls in the first weeks of life.
• Small defects usually cause no symptoms.
• A hyperactive precordium may be palpated, occasionally with a thrill, at the lower left sternal border.
• Murmur intensity is not reliably related to defect size.
• Chest x-ray shows cardiomegaly with evidence of increased pulmonary blood flow.
• VSDs tend to diminish in size with time with spontaneous closure of approximately 75% of small defects and between 25-50% of all defects.

Question 19

Treatment of CHF

Answer 19

• Furosemide (Lasix)
• Digoxin
• Enalapril

Question 20

Evaluation of Congenital Heart Defect

Answer 20

• ecg: expected to be abnormal, demonstrating chamber enlargement.
• CXR
• echo (meh)

Question 21

Hallmark chest x-ray findings of a large left-to-right shunt due to a congenital heart defect:

Answer 21

Cardiomegaly

Increased pulmonary vascular markings Pulmonary edema

Question 22

ECG Findings with VSD

Answer 22

The typical ECG findings for an infant with a large VSD are prominent biventricular forces (high voltage QRS complexes in leads V1 and V2), suggesting both LV volume overload and RV pressure overload.

Question 23

heart murmur from a VSD

Answer 23

typically not appreciated in the immediate newborn period, as the pulmonary vascular resistance is still quite elevated. During this time, since the pulmonary vascular resistance equals the systemic vascular resistance, there is no shunting of blood through the open VSD. However, after a few days to weeks after birth, the pulmonary vascular resistance decreases, and the murmur appears, reflecting the shunted flow of blood through the open VSD (from left to right).

Question 24

widely split, fixed S2 indicates an atrial septal defect (ASD)

Answer 24

often detected in children when they’re between 3 and 5 years old. The systolic murmur is due to the increased blood flow across the pulmonic valve. The widely split fixed second heart sound indicates an ASD is the cause of the murmur rather than an innocent heart murmur.

Question 25

fetal circulation

Answer 25

foramen ovale connects the RA to the LA, allowing a portion of the blood to bypass the RV and the lungs. Approximately a third of the blood that enters the RA passes through this route (preferentially the most oxygenated which is then delivered to the brain and heart), leaving the majority of the blood to travel into the RV. Closure of the foramen ovale is a normal transition from fetal to extrauterine circulation.

Question 26

atrial septal defects (ASDs) do not cause CHF

Answer 26

ASD malformation is a left-to-right shunt, and-depending on the size of the defect-the patient may or may not present with symptoms. ASDs often go undiagnosed for decades due to subtle physical examination findings and/or a lack of appreciable symptoms. If the defect is large enough, pediatric patients may present with easy fatigability, recurrent respiratory infections, or exertional dyspnea.