Wheezing infants may have asthma, but be alert for heart failure as well
Wheezing infants may have asthma, but be alert for heart failure as well: Excerpt from Avoiding Common Pediatric Errors
Author:
Russell Cross, MD
What to Do - Interpret the Data
Wheezes are coarse whistling sounds generated by vibration of a narrowed airway from turbulent airflow. Wheezing often is equated with
asthma, reactive airways disease, bronchiolitis, or other respiratory disease.
Wheezing, however, is also a common finding in infants and children with
congestive heart failure. Cardiac asthma may be defined as the clinical
syndrome induced by acute passive congestion and edema of the lungs.
The classic explanation for wheezing during pulmonary edema is that
bronchial wall edema and intraluminal edema fluid cause narrowing of the
small airways, but bronchial hyperresponsiveness also plays a part. This
bronchoconstriction is mediated by unmyelinated C-fiber nerve endings in
bronchi, pulmonary vasculature, and lung parenchyma (J or juxtacapillary
receptors). In animal studies, these receptors, which are carried in the
vagus nerve, have increased their activity fivefold as a result of pulmonary
edema.
In infants, heart failure may be difficult to identify. Infants whose bronchioles are proportionately narrow as compared to adults will not typically
have crackles with pulmonary edema but rather wheezes. Consequently, the
signs of cardiac-induced pulmonary congestion may be indistinguishable
from bronchiolitis or asthma. A history of feeding disturbance, slow weight
gain, diaphoresis should raise the suspicion of cardiac disease. Further confounding the diagnosis, pneumonitis with or without atelectasis, especially
in the right middle and lower lobes is common in children with heart disease
due to bronchial compression by the enlarged heart. Physical exam findings
can help distinguish heart failure from respiratory disease. Hepatomegaly
is a common finding in infants and children with heart failure. The cardiac
examwillshowincreasedprecordialactivity.Auscultationmayrevealagallop
or murmur. The presence of these features should prompt further workup
with an electrocardiogram and chest x-ray. Cardiomegaly is very frequent in
children with significant heart disease.
When presented withthe older childwith a firstepisode of acute wheezing, assessment for heart disease is equally important. Myocarditis or dilated
cardiomyopathy can present similarly as RAD. Consideration of heart disease is especially important in children who do not seem to respond to bronchodilator therapy. A history of exercise intolerance, weight loss or gain, or
a negative family history of asthma or allergies raises the suspicion of heart
disease. Again, the clinician should make note of the presence or absence of
hepatomegaly or jugular venous distention.
The chest radiograph is an important tool for the pediatrician in distinguishing cardiac versus respiratory disease. Cardiomegaly is frequent in
children with heart disease, and this finding, whether unexpected or not,
requires further workup for myocardial or pericardial disease. Additional
findings on chest radiograph include increased pulmonary vascularity. Infants and children with large left-to-right shunts have exaggeration of the
pulmonary arterial vessels to the periphery of the lung fields, whereas patients with cardiomyopathy may have a relatively normal pulmonary vascular bed early in the course of disease. Fluffy perihilar pulmonary markings
suggestive of venous congestion and acute pulmonary edema are seen only
with most severe degrees of heart failure.
Table 124.1 Etiology of Heart Failure by Age Group
Fetal
• Severe anemia (hemolysis, fetomaternal transfusion, parvovirus B 19-induced anemia, hypoplastic anemia
• Supraventricular tachycardia
• Ventricular tachycardia
• Complete heart block
Premature Neonate
• Fluid overload
• Congenital heart defects (patent ductus arteriosus, ventricular septal defect)
• Cor pulmonale associated with bronchopulmonary dysplasia
• Hypertension
Full-term Neonate
• Myocardial dysfunction (asphyxia, arrhythmia, sepsis)
• Arteriovenous malformation (vein of Galen)
• Left-sided obstructive lesions (coarctation of the aorta, hypoplastic left heart syndrome)
• Large mixing cardiac defects (single ventricle, truncus arteriosus)
• Viral myocarditis
• Dilated cardiomyopathy
Infant–Toddler
• Left to right cardiac shunts (ventricular septal defect, patent ductus arteriosus)
• Hemangioma (arteriovenous malformation)
• Anomalous left coronary artery from the pulmonary artery
• Metabolic cardiomyopathy
• Acute hypertension (hemolytic uremic syndrome)
• Supraventricular tachycardia
• Kawasaki disease
• Viral myocarditis
The differential diagnosis for children with congestive heart disease is
longandage-dependent(Table124.1 ).Theageofthepatientisaveryimportant feature. For instance, immediately after birth, congestive heart failure
or cardiogenic shock is most frequently related to myocardial dysfunction
from sepsis, asphyxia, arrhythmia, or a primary cardiomyopathy. Children
with large left-to-right shunts from a ventricular septal defect or patent
ductus arteriosus do not present until the pulmonary vascular resistance
falls, typically around 4 to 6 weeks of life. Older children develop congestive
heart failure from primary or secondary cardiomyopathies. Secondary cardiomyopathycandevelopfromprolongrunsofsupraventriculartachycardia.
Approximately half of patients with incessant supraventricular tachycardia
lasting >48 hours will have heart failure. Cardiology consultation should be
considered in any child with heart failure or cardiomegaly.
Suggested Readings
Krieger BP. When wheezing may not mean asthma. Other common and uncommon causes to
consider. Postgrad Med. 2002;112(2):101–102, 105–108, 111.
McColley SA. Extrapulmonary Disease with Pulmonary Manifestations. In: Behrman RE,
Kliegman RM, Jenson HB, eds. Nelson Textbook of Medicine. 17th ed. Philadelphia:
Saunders; 2004: pages 1471–1472.
Book Source Details
- Book Title: Avoiding Common Pediatric Errors
- Author(s): Anthony D Slonim MD, DrPH; Lisa Marcucci MD
- Year of Publication: 2008
- Copyright Details: Avoiding Common Pediatric Errors, Copyright © 2008 Lippincott Williams & Wilkins.
More About Heart failure
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- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: Avoiding Common Pediatric Errors
Authors: Anthony D Slonim MD, DrPH; Lisa Marcucci MD
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7489-6
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