Screening Cardiovascular status-Infant

Summary of Recommendation and Evidence

Population	Recommendation	Grade (What's This?)
Screening of both Genders	This screening is recommended a best practice.	B

The evaluation of the cardiovascular system focuses on the heart, but should also include an assessment for disease in the arterial system throughout the body.

The major elements of the cardiac exam include observation, palpation and, most importantly, auscultation.

Age of Onset of Congestive Heart Failure

The clinical significance of the age of onset of congestive heart failure is as follows:

1. If symptoms develop in a child because of congenital heart disease, there is a 95% probability that the symptoms will develop before the age of 3 months and usually before 2 months.

2. Heart failure is rarely present at birth, because the fetal circulation is in parallel and communications occur between the two sides; thus when there is obstruction on one side, blood flows easily to the other side. Because the fetal lungs are collapsed, they have a high resistance, so increased pulmonary blood flow does not occur in utero.

3. When heart failure is present right at birth, myocardial dysfunction (either resulting from a cardiomyopathy or related to in utero hypoxia) or severe AV valve regurgitation should be the primary considerations. Large systemic arteriovenous fistulae also can cause very early heart failure.

4. Heart failure that develops during the first week of life, and especially in the first 3 days, usually is due to an obstructive lesion, commonly hypoplastic left heart syndrome, or to persistent pulmonary hypertension.

5. Heart failure that develops 4 to 6 weeks after birth almost invariably is due to left-to-right shunting through a defect distal to the tricuspid valve (i.e., beyond the atrial level). These lesions cause LV volume overload. Pulmonary resistance is high at birth and, although a communication may exist between the two circulations, little left-to-right shunting occurs. Pulmonary resistance usually reaches its nadir by 4 to 6 weeks of age, allowing left-to-right shunting to reach a maximum.

6. If heart failure develops after the age of 3 months, look for causes other than shunts, such as myocarditis, anomalous coronary artery from the pulmonary artery, cardiomyopathy, and paroxysmal tachycardia.

Family history

When there is a history of congenital heart disease in one parent or in a previous child, counseling regarding the risk of recurrence is best done by a geneticist.

Prenatal history

Because the cause of congenital heart disease is multifactorial, known contributory factors should be sought in the prenatal history, including:

1.Exposure to drugs (e.g., lithium, hydantoin, and thalidomide)

2. Alcohol intake

3. Possible rubella in the first trimester (check the mother’s rubella immunization status)

4. Maternal diabetes (which bestows a higher risk of congenital heart malformations)

5. Exposure to radiation

Classification of Heart Disease in Children

Heart disease in children takes several forms. These types of heart disease may be divided into the following categories:

Congenital: This category can be further divided into:

1. Structural cardiac changes present at birth (e.g., ventricular septal defect [VSD] or bicuspid aortic valve).

2. Genetic disorders that lead to overt changes or symptoms that develop after birth (e.g., cardiomyopathies or inherited rhythm disorders, such as long QT syndrome).

Acquired: Acquired heart diseases are those not manifested at birth but acquired sometime later. The most common acquired heart diseases in children are Kawasaki disease and rheumatic fever. Although acquired diseases may arise from a combination of genetic and environmental factors, the diseases themselves are not present or inevitable when the child is born. Almost any disease process that affects adults can occur in children. However, in children, acquired heart disease is much less common than congenital heart disease.

Initial assessment

When you start the examination, don’t undress the baby right away. Begin with something relatively non-threatening, such as an examination of the hands. The baby usually allows you to examine the palmar creases and to check the nail beds and muscle tone without much protest. Then feel the brachial pulses for rate, rhythm, and volume, the last being the most important. Feel this pulse in every baby you examine to learn the difference between a normal and abnormal brachial pulse. An abnormally “full” pulse suggests a PDA or aortic insufficiency. In premature infants, palpable palmar pulses (from the palmar arch) indicate the same thing. A shallow, slow-rising brachial pulse suggests LV outflow tract obstruction. Do not feel for the femoral pulses yet.

Clinical manifestations of heart failure

When low cardiac output and high pulmonary venous pressure cause sufficient hemodynamic disturbance to produce clinical manifestations, cardiac enlargement is invariably present. Whether the disturbance involves primarily the left or the right ventricle, the left side of the thorax becomes prominent anteriorly. Although this prominence may not be evident in the first month of life, it certainly will be evident by the age of 3 months. When respiratory distress due to heart failure has been present for 2 months or longer, the greater diaphragmatic contractions during respiration may produce a sulcus in the lower thorax, with outward flaring of the inferior rib cage edge. Therefore, look for a sulcus, left-sided chest prominence, abnormal chest or abdominal movement, an increased respiratory rate, and subcostal indrawing.

Prominence of the left side of the chest in a 3-year-old with ventricular septal defect and moderate left-to-right shunt that is causing enlargement of both left and right ventricles.