Flashcards in Case 18 Deck (46):
What are key findings from history in a child with a VSD and CHF?
Poor feeding, respiratory distress, diaphoresis
What are key physical exam findings from a child with VSD?
Tachypnea, Murmur, hepatomegaly
What is on the differential diagnosis for VSD/CHF?
Bronchiolitis, Pneumonia, GERD, Metabolic disorder
What is seen in a CXR of VSD?
Cardiomegaly, increased pulmonary vascular markings, and pulmonary edema (hallmark findings of a large left-to-right shunt due to congenital heart defect)
What is seen on electrocardiogram of VSD?
Prominent biventricular forces (high voltage QRS complexes in leads V1 and V2), suggesting both LV volume overload and RV pressure overload
What is seen on an echocardiogram of VSD?
2D ECHO demonstrates a large perimembranous ventricular septal defect in the sub-aortic region
Definition of a VSD?
Any persistent communication between the ventricles occurring in isolation or as part of a more complex defect.
What is the anatomy associated with VSD?
Defect of variable size located along embryologic lines of fusion in the ventricular septum.
What is the physiology associated with VSD?
-Left-to-right shunting of blood during ventricular systole causes increased pulmonary blood flow, increased pulmonary venous return, and resultant left ventricular volume overload.
-Magnitude of the shunt depends on size of defect and difference between systemic and pulmonary vascular resistance.
-Newborns have elevated pulmonary vascular resistance. Because the systemic and pulmonary vascular resistances are nearly equal, there is no reason for blood to shunt through the VSD. The murmur of a VSD will appear when the PVR drops, usually at a few days to weeks of age.
What is the presentation of VSD?
-Murmur and clinical signs usually not present in the newborn nursery but are noted from several days to weeks of age.
-Age of presentation and symptoms related to magnitude of left to right shunt.
-Large defects often present with CHF as pulmonary resistance falls in the first weeks of life.
-Small defects usually cause no symptoms
-VSDs tend to diminish in size with time. There is spontaneous closure of approximately 75 percent of small defects and between 25-50 percent of all defects.
-Hyperactive precordium frequently with a thrill at the lower left sternal border.
Etiology of CHF in infancy:
-Heart defects that present with a murmur and signs of CHF in infancy include VSD, severe aortic stenosis or coarctation of the aorta, and a large patent ductus arteriosus (PDA).
-Many other congenital heart defects, such as ASD, do not cause CHF. Most cyanotic heart defects, like tetralogy of Fallot, cause decreased pulmonary blood flow and therefore doe not cause CHF.
How do CHF present in infancy?
-Infants with heart disease are generally otherwise healthy.
-Typically presents with predominantly respiratory symptoms (tachypnea) and feeding difficulties
-The history will often reveal that infant is feeding for longer periods of time than norma, and that feedings are terminated due to respiratory distress.
-Infants frequently become diaphoretic with feedings. Diaphoresis suggests adrenergic activation and is a major sign of CHF in infants.
-Ultimately, due to poor feeding and increased caloric expenditure, poor weight gain ensues (Failure to thrive)
-Hepatomegaly is a reliable finding in infants with heart failure:
--Decreased renal blood flow via activation of renin-angiotensin system leads to fluid retention, systemic venous congestion and hepatomegaly
How often do breastfeeding and bottle feeding infants usually nurse?
-Young, breastfeeding infants usually nurse for 20-30 min, as often as every 1-2 hours.
-Bottle-fed infants often take more per feed and feed a little less often
How would a problem with maternal breast milk production present?
It would be more likely to present with the infant trying to feed more frequently and continually acting hungry.
Weight loss in a newborn:
-Newborns typically lose between 5-10 percent of their birth weight in the first few days after birth. Most will be back to birth weight by 10-14 days.
-Failure to gain weight adequately in infancy or childhood is referred to as "failure to thrive"
What is a strong indicator of coarctation of the aorta?
A discrepancy in the strength of the brachial and femoral pulses.
What is a simple way to grade murmur intensity?
Grade I - faint and easily missed.
Grade II - obvious
Grade III - loud
Grade IV - Associated with a thrill
What grade of murmur is likely to be pathologic?
Any grade III or IV murmur is likely to be pathologic, and probably should be evaluated by a cardiologist.
What are other pathologic murmurs?
-Diastolic murmurs are always pathologic
-Congenital heart defects must always be considered when evaluating a child with a murmur
-Acute rheumatic fever, endocarditis, and cardiomyopathies are uncommon causes of heart murmurs in children, but also must be considered, particularly in a child with a murmur and fever.
What are the common congenital heart defects?
Atrial septal defect, Aortic stenosis, Coarctation of the aorta, patent ductus arteriosus, pulmonic stenosis, ventricular septal defect.
Atrial septal defect (ASD):
The pathognomonic physical finding of an ASD is a widely split, fixed S2. The systolic murmur is due to increased flow across a normal pulmonic valve. Listening for wide splitting of the second heart sound is the most helpful way to distinguish an ASD from an innocent murmur. ASDs are often first detected at 3-5 years of age.
A systolic ejection murmur often followed by an early diastolic murmur of aortic insufficiency. Aortic stenosis most commonly presents in infancy.
Coarctation of the aorta:
It can present in infancy or at any age beyond because it tends to be a progressive problem, growing more severe over years. Coarctation presents with a murmur, HTN in the upper extremities, and a discrepancy between the upper and lower extremity blood pressures.
Patent ductus arteriosus (PDA):
A continuous murmur, but a bit louder in systole. PDAs most commonly present in infancy.
Typically a prominent systolic ejection click just after S1, and a harsh systolic ejection murmur. Pulmonic stenosis most commonly presents in infancy.
Ventricular septal defect (VSD):
This murmur is holosystolic, starting with S1. Its intensity is not reliable related to defect size. The murmur can have different qualities, from soft and blowing to harsh and loud. VSDs most commonly present in infancy.
-By far the most common cause of a murmur in children, particularly at 3-7 years of age.
-An innocent murmur is by definition normal, and is not due to any heart abnormality.
-A murmur heard in a young infant or child who is not otherwise healthy is less likely to be innocent.
-The most commonly heard innocent murmur is the Still's murmur.
What is the Still's murmur?
The most commonly heard innocent murmur. This is often described as musical or vibratory, and is heard best at the left lower sternal border in the supine position. The vibratory quality is the most characteristic feature of an innocent murmur.
In deciding if a murmur is innocent, it is important to make sure there are no other signs of significant heart disease. Questions to ask yourself:
-Is the child otherwise well?
-Is the precordial activity normal?
-Is the second heart sound normally split?
-Is the murmur more than grade II/VI?
-Is the oxygen saturation normal?
If the answer to any of these questions is "no," the murmur should not be considered innocent.
What is a Gallop?
A gallop is an extra heart sound, quite different in character from a murmur, and very uncommonly heard in infants and children. A gallop rhythm is noted more often with primary cardiac contractile dysfunction than with volume overload lesions.
What is on the differential diagnosis for CHF?
Metabolic disorders, Bronchiolitis or pneumonia, sepsis, GERD.
Congestive heart failure (CHF):
CHF often presents with a history of respiratory distress, difficulty feeding, and poor weight gain (also called failure to thrive). There are many potential causes of CHF in infancy.
Many metabolic disorders could potentially cause poor feeding. A negative newborn screen makes this less likely, but still lan important possibility. Hepatomegaly can be found in many metabolic disorders (although jaundice might also be expected), and tachypnea may be a sign of metabolic acidosis.
Bronchiolitis and pneumonia:
These present with respiratory distress, pneumonia typically also with fever. Bronchiolitis is very common, and presents with predominantly respiratory distress. Anything causing respiratory difficulty (increased work of respiration) in infants can also cause difficulty with feedings. Tachypnea is more likely to indicate a pulmonary process than heart disease.
Poor feeding may be a sign of gastrointestinal disease, but the absence of spitting up or emesis makes this less likely.
CXR with CHF:
Hallmark radiologic findings of a large left to right shunt due to a congenital heart defect are cardiomegaly, increased pulmonary vascular markings, and pulmonary edema.
ECG in patient with large VSD:
Shows prominent biventricular forces - high voltage QRS complexes in leads V1 and V2 - suggesting both LV volume overload and RV pressure overload (from pulmonary HTN).
ECHO in patient with large VSD:
Use of echocardiography in teh primary pediatric care setting is controversial, and most pediatric cardiologists agree that it is not appropriate as first-line testing. An ECHO costs about $1500, a consult with a pediatric cardiologist, about $200. An echo is more informative when combined with a cardiology consultation.
Cardiac magnetic resonance imaging (MRI):
Cardiac MRI is an emerging tool for evaluating congenital heart defects, but is available only in tertiary centers. A young infant would require anesthesia to obtain adequate images.
Cardiac computed tomography (CT):
Cardiac CT is not as good as echocardiography for intracardiac anatomy and requires a high dose of radiation.
Initial management of congenital heart disease:
-Not all children with CHD need to be admitted to the hospital; many may be seen by a pediatric cardiologist as an outpatient.
-Children with significant congenital heart defects presenting with cyanosis or CHF need to be admitted to the hospital for management
-All children in shock need to be admitted urgently to an ICU.
-For other patients, the decision to admit is based on the severity of illness and the tempo with which the patient's symptoms are evolving:
--Findings such as increased respiratory effort, lethargy/decreased level of alertness, feeding difficulty, or cyanosis merit referral for admission for evaluation and management of symptomatic congenital heart disease.
Diuretics to treat congestive heart failure in kids:
-Effective at relieving symptoms of CHF.
-Counteract the fluid retention that occurs as a result of activation of the renin-angiotensin system
-Furosemide (lasix) is the diuretic used most commonly for CHF in infants.
Digoxin to treat congestive heart failure in kids:
-Shown in some studies to improve symptoms in infants with CHF due to VSD
-Mechanism of the improvement is not altogether clear, as infants with a VSD do not have impaired contractility.
Nutrition for CHF in kids:
-High-calorie formula (30 calories/ounce) may be considered if patient fails to gain adequate weight.
Treatment of pulmonary HTN in a child with CHF:
-If pulmonary HTN is left untreated for several years, pulmonary vascular obstructive disease (also known as Eisenmenger's disease) may develop.
-The decision about whether to proceed with surgery in an infant with a VSD should be made by 6 months of age to eliminate the risk of Eisenmenger's disease.