Pediatric Examination and Board Review (9 page)

(A)
Staphylococcus aureus
(B) streptococcus infection

(C) Epstein-Barr virus

(D) enterovirus

(E) influenza A virus

13.
Which of the following should be avoided for the treatment of acute myocarditis?

(A) dopamine

(B) IV immunoglobulin

(C) supportive therapy with diuretics

(D) IV digoxin

(E) dobutamine

14.
Which therapy would not be considered standard management for patients with chronic congestive heart failure?

(A) beta-blockers

(B) diuretics

(C) angiotensin-converting enzyme (ACE) inhibitors

(D) calcium channel blockers

(E) digoxin

15.
A 7-year-old patient presents with heart murmur, chest pain, and shortness of breath. The murmur is a continuous type that varies in quality with position changes. The patient seems to have relief when sitting and leaning forward. The heart sounds are distant. What is the likely diagnosis for this patient?

(A) pulmonary embolus

(B) pericarditis

(C) myocardial infarction

(D) gastroesophageal (GE) reflux

(E) pleural effusion

16.
What is the most common cause of this 7-year-old’s diagnosis among young patients in the United States?

(A) viral infection

(B) acute rheumatic fever

(C) bacterial infection

(D) collagen vascular disease

(E) drug induced

17.
While in the office, the 7-year-old patient becomes lethargic with poor perfusion and hypotension. What is the most likely explanation?

(A) pulmonary embolus

(B) myocardial infarction

(C) stroke

(D) cardiac tamponade

(E) arrhythmia

ANSWERS

1.
(A)
The patient most likely has a Still murmur. This is described as a vibratory or musical systolic ejection murmur occurring at the left sternal border with no other associated cardiac findings. It is the most common innocent heart murmur in children and usually presents at 2-7 years of age. Other innocent murmurs include pulmonary outflow tract murmur, the peripheral pulmonary stenosis murmur of the newborn, and a venous hum. The incidence of innocent heart murmurs in young patients after infancy is approximately 17-66%.

2.
(B)
Features of innocent heart murmurs include not only the quality and location of the heart murmur but also the fact that the first and second heart sounds are normal. The murmurs are usually welllocalized without much radiation and are usually graded between 1 and 3 with no associated precordial thrill. The murmurs are usually described as vibratory, musical, or blowing, and they are louder in the supine position compared with the sitting or standing position. This is not the case with the innocent venous hum that is often louder in the sitting position. A venous hum can be distinguished by the great amount of variability in quality with position changes and with turning the head. Innocent murmurs do not typically have a diastolic component. A split, fixed second heart sound is associated with an atrial septal defect.

3.
(D)
Common tests performed in evaluation of innocent heart murmurs include 12-lead ECGs, chest radiographs, 4-extremity blood pressure (to rule out coarctation of the aorta) and echocardiograms. The use of these tests is at the discretion of the examining physician and depends on the findings on physical examination as well as the past medical and family history. An invasive procedure such as a cardiac catheterization is usually not recommended for evaluation of an innocent heart murmur if the tests just listed have been normal.

4.
(C)
Innocent heart murmurs are not associated with any increased risk for bacterial endocarditis; thus prophylaxis is not needed. Sports participation is not restricted because there is not an increase in cardiac events associated with innocent heart murmurs. Innocent murmurs, by definition, are not associated with structural heart disease, so yearly echocardiograms are usually not recommended. There is no familial association with structural heart disease. Depending on the age at time of diagnosis, a followup visit is occasionally recommended for younger patients.

5.
(C)
The child presents with evidence of congestive heart failure. In addition to the clinical findings described, other findings associated with congestive heart failure include edema, usually of the eyelids or in dependent areas, jugular venous distention, an S3 or S4 gallop on examination, and cardiomegaly or pulmonary edema demonstrable on chest radiograph.

6.
(D)
Evaluation of a young patient with congestive heart failure requires a physical examination to assess for edema, hepatomegaly, pulmonary congestion, and cardiac gallop. An echocardiogram is used to assess cardiac function and any associated cardiac structural abnormalities. A 12-lead ECG is used to assess for any ischemic changes, arrhythmias, or bradycardia. A chest radiograph is helpful to assess for cardiomegaly or pulmonary edema as well as to assess for any obvious primary pulmonary disorders. A throat culture would not be useful at this age for evaluation of heart failure.

7.
(C)
Cardiac lesions that present with heart failure at this age are usually a result of an increase in the amount of left-to-right shunting secondary to the natural decrease in the pulmonary vascular resistance. Common left-to-right shunting lesions include a ventricular septal defect, a patent ductus arteriosus, a large coronary artery fistula, and an aortopulmonary window. Atrial septal defects do not usually present with heart failure at this age mainly because the amount of left-to-right shunting depends on the compliance of the right ventricle rather than the drop in pulmonary vascular resistance.

8.
(A)
An anomalous left coronary artery arising from the pulmonary artery is a rare congenital heart defect. The right coronary artery arises normally from the aorta. A number of collateral vessels develop between the right and left coronary arteries, and thus, when there is a drop of pulmonary vascular resistance, a “steal phenomenon” occurs with coronary blood essentially flowing from the aorta to the right coronary artery across the collaterals to the left coronary artery and into the pulmonary artery. Because of this, certain areas of the myocardium are at risk for ischemia. Patients with this lesion often present at 6-8 weeks of age with extreme irritability (especially at the onset of feeding) that is a result of angina. Other symptoms such as diaphoresis, weight loss, hepatomegaly, and decreased frequency of wet diapers occur at a similar frequency to other conditions associated with heart failure.

9.
(B)
Acute management of heart failure because of left-to-right shunting lesions include inotropic support with digoxin, dopamine, dobutamine, or epinephrine. Diuretics are also used to relieve symptoms of edema. Milrinone is an inotrope and afterload-reducing agent that is commonly employed for the treatment of heart failure. Use of oxygen may exacerbate symptoms of heart failure in the presence of left-to-right shunting lesions by decreasing pulmonary vascular resistance and increasing the degree of left-to-right shunting. The ultimate long-term therapy is to eliminate the left-to-right shunting lesion either with surgery or interventional cardiac catheterization.

10.
(D)
Myocardial dysfunction resulting in dilated cardiomyopathy is uncommon in the pediatric population. The causes include myocarditis, metabolic diseases, idiopathic, familial dilated cardiomyopathy, or tachycardia-induced cardiomyopathy. Ischemic heart disease is a rare cause of dilated cardiomyopathy at this age but is the most common cause in the adult population.

11.
(B)
Myocarditis is defined as inflammation of the myocardium thought to occur because of a cellmediated immunologic reaction. The diagnosis is confirmed by endomyocardial biopsy showing fibrosis and inflammation. A biopsy showing fibrosis alone may be seen with any form of cardiomyopathy and is not specific for acute myocarditis. Other features suggestive of myocarditis include tachycardia out of proportion to the symptoms of heart failure, cardiac dysfunction, a pericardial effusion, and a preceding history of upper respiratory illness. A systolic flow murmur, hepatomegaly, and S3 gallop may occur with myocarditis but are nonspecific findings for this diagnosis.

12.
(D)
The most common cause of myocarditis is infection due to enterovirus (eg, coxsackievirus and echovirus) as demonstrated by polymerase chain reaction (PCR) of endomyocardial biopsies. Other agents include other viruses (such as adenovirus and Epstein-Barr virus), bacteria, rickettsia, fungi, protozoa, and parasites. Other etiologies include immunemediated diseases, toxic myocarditis, and collagen vascular diseases.

13.
(D)
The acute management of myocarditis includes the use of steroids, IV immunoglobulins, diuretics, and inotropic support. Use of IV digoxin during the acute phase of myocarditis is associated with increased occurrence of arrhythmias and is thus typically not recommended. There are conflicting data regarding the efficacy of these therapies, and no single therapy has shown to significantly improve the long-term outcome in patients with myocarditis. Generally, most patients improve and have complete recovery, although the acute mortality rate may be as high as 75% in neonates.

14.
(D)
In patients with ventricular dysfunction and chronic congestive heart failure, therapy includes the use of diuretics and digoxin. The use of afterloadreducing agents such as ACE inhibitors has been shown to reduce morbidity and mortality. The recent use of beta-blockers has been shown to decrease myocardial oxygen demand and also decreases morbidity and mortality among adults with ventricular dysfunction. The use of calcium channel blockers is not recommended because of the significant negative inotropic effect. The long-term management for patients with ventricular dysfunction and heart failure includes medical therapy and routine monitoring with exercises tests to obtain objective data regarding cardiac performance.

15.
(B)
The most likely diagnosis of this patient is acute pericarditis. This is defined as inflammation of the parietal and visceral pericardium and results in serous hemorrhagic or purulent pericardial effusion. The clinical manifestations include a pericardial friction rub and the presence of a dull substernal chest pain that improves when leaning forward. There may be a history of upper respiratory tract infection and fever.

16.
(A)
The most common agents causing pericarditis in the United States are viruses. Acute rheumatic fever is a common cause in certain parts of the world. Other causes include bacterial infection, collagen vascular disease, tuberculosis, oncologic disease, and uremia.

17.
(D)
Cardiac tamponade is the most likely cause of this patient’s acute decompensation. The clinical features of cardiac tamponade include distant heart sounds, tachycardia, pulsus paradoxus, hepatomegaly, venous distention, and hypotension. The diagnosis can be confirmed with an echocardiogram. Acute management would include pericardiocentesis or surgical drainage of the pericardial fluid. Long-term management is directed at the cause of the pericarditis.

Pulsus paradoxus is defined as a drop of 10 mm Hg or more in the systolic blood pressure with breathing. The normal variability of systolic blood pressure with breathing (<10 mm Hg) results from fluctuation of left ventricular filling because intrapulmonary pressures vary with respiration. This phenomenon is exaggerated with cardiac tamponade and may also occur with pulmonary embolism, obstructive respiratory disease, or hypotension.

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