This chapter reviews the most common types of acquired heart
disease in children: inflammatory and infectious disorders, and
cardiomyopathies, of which the most important is hypertrophic cardiomyopathy
Myocarditis is an inflammatory disorder of the myocardium affecting children
of all ages and is the leading cause of end-stage cardiomyopathy requiring
transplantation. Viral causes include enteroviruses (coxsackie, echovirus,
and poliovirus), as well as mumps, influenza virus, and varicella
zoster virus. Emerging causes are human immunodeficiency
virus–associated myocarditis and chronic Epstein-Barr myocarditis.
Many bacterial species have been associated with myopericarditis
but not myocarditis alone. Noninfectious causes include conditions
such as Kawasaki disease (see discussion below in Kawasaki
Disease) and lupus erythematosus.
Myocarditis is often preceded by a viral respiratory illness.
Presenting signs and symptoms are often respiratory distress, fever, tachypnea,
tachycardia, generalized malaise, fever, and myalgias. Vomiting,
decreased activity, and poor feeding are present. Arrhythmias may complicate
myocarditis and give rise to symptoms of palpitation or syncope
in older children. Chest pain may be a symptom of concurrent pericarditis.1–3
The physical examination reveals signs of decreased cardiac output
and compensatory response: tachycardia, weak pulses, cool extremities
with delayed capillary refill, skin mottling, or cyanotic skin.
Auscultation of the heart may reveal distant heart sounds, an S3 or
S4 gallop, and a regurgitant murmur. There may be signs
of congestive heart failure.
Diagnostic evaluation includes complete blood count, serum chemistries,
and blood cultures to identify bacterial infection. Inflammatory
markers, such as erythrocyte sedimentation rate and C-reactive protein,
are nonspecific but may be elevated. Respiratory viral cultures
or viral titers may help to identify a specific infectious cause.
Troponin T or I may be elevated.
ECG changes are nonspecific, with sinus tachycardia, low QRS
voltages (<5 mm in limb leads), flattened or inverted T waves
with ST- and T-wave changes, and prolongation of the QT interval.
Left ventricular hypertrophy or strain can be seen. Arrhythmias
include premature ventricular contractions, atrial tachycardias,
junctional tachycardia or, occasionally, heart block, or ventricular
Chest x-ray may reveal cardiomegaly and pulmonary edema, and echocardiography
is useful to define cardiac function. Biopsy is the diagnostic gold
Treatment of myocarditis depends upon the cause. Treatment
of heart failure also depends on the specific cause, and treatment modalities
need to be individualized. Treatment consists of afterload reduction,
preload reduction in the case of true volume overload, or inotropic
support. Diuretics will worsen the condition if cardiac output depends
upon preload.1–3 Children with heart failure
need admission to a tertiary care pediatric facility.
Pericarditis is inflammation of the pericardium and has many
causes. Infectious causes are common and can be bacterial, viral,
fungal, parasitic, or tubercular. Viral etiologies predominate in
the infant. Pericarditis is often associated with myocarditis, with
myocarditis the predominant entity. Staphylococcus aureus, Streptococcus
pneumoniae, Haemophilus influenzae, Neisseria
meningitidis, and streptococci species are causes of bacterial
pericarditis. Noninfectious inflammatory causes include acute rheumatic
fever, collagen vascular disease, Kawasaki disease, and uremia.
Rarely, pericarditis may be caused by malignant disease, including leukemia,
lymphoma, and cardiac rhabdosarcoma.
Pericarditis often follows or accompanies upper respiratory infection.
Chest pain, usually benign in children, may be a symptom of pericardial
inflammation and is classically positional, with worsening in the
supine position and improvement leaning forward.
Vital signs may reflect tachycardia, tachypnea, and hypotension
with a narrow pulse pressure. Pulsus paradoxus is the sine qua non
of pericardial effusion with cardiac tamponade and is defined by
a 20 mm Hg fall in systolic blood pressure with inspiration. Auscultation
of the heart may reveal a friction rub, and muffled or distant heart
sounds. Peripheral pulses may be decreased with cool extremities,
mottled skin, and sluggish capillary refill.
Routine blood tests are not typically helpful for diagnosis,
but specific testing may identify the cause: a positive purified
protein derivative or Mantoux screening test suggests
tuberculosis, circulating blasts indicate hematologicmalignancy,
and positive blood cultures may occasionally be seen in bacterial
ECG findings include decreased precordial voltage in the setting
of large pericardial effusions. Diffuse ST elevations and T-wave
inversion are also common and indicate myocardial involvement. Sinus
tachycardia is usually present.
The chest x-ray may demonstrate cardiomegaly with a water bottle–shaped
heart, or a pleural effusion. Echocardiography is best to detect
pericardial effusion or tamponade. If a tamponade is present, there
will be collapse of the right atrial wall or right ventricular wall
Treatment depends upon the underlying cause. Tamponade requires
emergency pericardiocentesis (see Chapter 59, The Cardiomyopathies, Myocarditis, and Pericardial Disease, and Chapter 37, Pericardiocentesis). Empiric antibiotic
therapy for bacterial pericarditis includes oxacillin, 50 milligrams/kg,
or vancomycin, 10 milligrams/kg, for methicillin-sensitive S.
aureus and methicillin-resistant S. aureus, with
the addition of gentamicin, 5 to 7.5 milligrams/kg, in
immunocompromised patients.3 The treatment of pericarditis
without effusion or tamponade includes outpatient treatment with
NSAIDs such as naproxen, 5 to 10 milligrams/kg/dose
every 12 hours.
Kawasaki disease (mucocutaneous lymph node syndrome) is a generalized
systemic vasculitis of unknown cause. Along with Henoch-Schönlein
purpura (see Chapter 124, Acute Abdominal Pain in Children, Chapter 134, Rashes in Infants and Children, and Chapter 128, Renal Emergencies in Infants and Children), Kawasaki disease is one of the principal
pediatric systemic vascular diseases. It affects infants and young
children and can occur in endemic and community-wide epidemic forms.4
Signs of Kawasaki disease are fever, bilateral nonexudative
conjunctivitis, lymphadenopathy, erythema of the mucous membranes,
rash, and extremity changes. Cardiac complications are the most
severe sequelae ...