CARDIAC FAILURE

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Last Updated : 5/11/2016
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Valerie Schroeder
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Recognizing Heart Failure
Children may develop heart failure any time in their lifespan. Heart failure is sometimes difficult to diagnose because clinical symptoms may be heterogeneous or non-specific (Table 1). Respiratory distress (tachypnea, retractions), hepatomegaly, exercise intolerance and abnormal cardiac examinations are universal findings (2, 3). However, age and genetic background create variability in the presentation. Infants are less likely to exhibit peripheral edema compared to older children. Children with trisomy or other chromosomal anomalies may be more ill appearing compared to those without. Adding to the complexity are the numerous etiologies of pediatric heart failure each with their own unique signs and symptoms. Furthermore, the prevalence of common heart lesions appears to vary by demographics. In developed countries, infants with heart failure most likely have congenital heart disease whereas older children will develop acquired disease or cardiomyopathy (Table 2). In contrast, within less developed countries, nutritional deficits, anemia, infection and rheumatic fever predominate (4).

Heart failure is diagnosed using the history, physical exam and laboratory findings (Table 1). These diagnostic findings should also be used rate the severity of heart failure as this dictates treatment decisions. Unlike adults however, rating the severity of heart failure in children has been a challenge. In part, this is due to the variability in age, diagnosis, activity level and physiology in children compared to adults (2). The New York Heart Association classification has not proven reliable in children. The original Ross scale is useful in infants from birth to 6 months of age but is not for older children (2). A modified (but non-validated) Ross scale (5) can be used for older children (Table 3). Likewise, the New York University Pediatric Heart Failure Index is useful for all ages but is not validated congenital heart disease. The scale is a weighted, combination of scores that takes into account symptoms, signs, single ventricle disease, and current treatments. The result is a range of scores from zero (no heart failure) to 30 (severe heart failure, 9). The scale appears sensitive for tracking fluctuations in the severity of heart failure for a given individual such as pre- and post- cardiac intervention.

Table 1. Common Signs and Symptoms of Heart Failure
Symptoms Shortness of breath at rest or with activity (feeding)
Fatigue
Edema
Nausea, anorexia, poor growth or weight loss (catabolic state)
Fussiness (infants)
 
Signs Tachycardia Tachypnea
Pulmonary rales (pulmonary congestion)
Pleural effusion (less common)
Jugular venous distension (older children)
Hepatomegaly
Facial or peripheral edema
Poor circulation or perfusion
 
Cardiac findings Murmur
Arrhythmia
Arm/leg blood pressure discrepancy (coarctation)
Loud P2 heart sound (pulmonary arterial or vascular hypertension)
Increased or shifted cardiac impulse (pressure or hypertrophy)
Gallop (diastolic dysfunction)
Muffled heart sounds (poor systolic function, large pericardial effusion)
Cardiomegaly
Abnormal EKG or Echocardiogram
Increased natriuretic peptide or troponin I


Table 2. Common Etiologies of Heart Failure Based Upon Age
Fetus
   Tachyarrhythmias and complete heart block
   Severe anemia
   Arteriovenous malformations
   Twin-twin transfusion
Premature infants
   Patent ductus arteriosus
   Volume overload
Term infants
   Congenital heart disease
         1st week of life: hypoplastic left heart syndrome, critical valve disease
         1-4 weeks of life: coarctation or other ductal dependent lesions
         4weeks-4 months of life: large ventricular or atrial septal defects, endocardial cushion defect, anomalous coronaries
Older children
   Failed congenital heart palliation
   Myocarditis/infection
   Cardiomyopathy
   Rheumatic heart disease
   Arrhythmia


Table 3. Modified Ross Heart Failure Classification
Class I
         Asymptomatic

Class II
         Mild tachypnea or diaphoresis feeding in infants, normal growth
         Dyspnea on moderate exertion in older children (1-10y age)

Class III
         Marked tachypnea or diaphoresis with feeding failure in infants
         Prolonged feeding times with growth failure
         Marked dyspnea with minimal exertion

Class IV
          Tachypnea, retractions, grunting, diaphoresis at rest


Heart Failure Pathophysiology

Once heart failure is recognized, the next step is to localize and describe the lesion or disease process. When localizing a cardiac process, one must determine whether the disease affects the left, right or both ventricles. Right and left heart diseases have distinct clinical characteristics whereas biventricular disease exhibits a combination of both.
Right Heart Failure – Ineffective forward flow of venous blood into the pulmonary circulation.
Right heart failure can result from pump dysfunction or obstruction to flow. This causes a backup of fluid in the body, resulting in swelling, edema, hepatomegaly, and jugular venous distension (older children, not infants). Ascites and pleural effusions are possible but uncommon. Examples include severe pulmonary hypertension, or severe pulmonic stenosis.
Left Heart Failure – Ineffective forward flow of arterial blood into the systemic circulation.
Left heart failure also results from myocardial dysfunction or obstruction. Back up behind the left ventricle causes accumulation of fluid in the lungs leading to respiratory distress and poor cardiac output. Examples include cardiomyopathy or severe aortic stenosis.
Biventricular disease- Children would exhibit a combination of the above findings. Examples include cardiomyopathy or arteriovenous malformation.
Ventricular failure can be further divided into systolic and diastolic dysfunction. The former is characterized by a reduced ejection fraction and an enlarged ventricular chamber, the latter by an increased resistance to filling. Both systolic and diastolic dysfunction may coexist (dilated cardiomyopathy) and one or both ventricles may be affected.
Systolic dysfunction- pump dysfunction
Cardiomyopathy
Arrhythmia
Severe valve or vascular obstruction (aortic stenosis, pulmonic stenosis, coarctation)
Severe systemic hypertension
Toxins/medications
Diastolic dysfunction- decreased compliance (stiffness)
Cardiac fibrosis or scarring
Hypertrophic cardiomyopathy
Pericardial effusion/Pericardial disease

References

Contributor Information and Disclosures Valerie Schroeder
Pediatric Cardiology Associate Professor
University of Kansas Medical Center Department of Pediatrics
3901 Rainbow Blvd, Kansas City, KS 66160


First Created : 1/12/2001
Last Updated : 5/11/2016
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Contributor Information and Disclosures

Last Updated : 5/11/2016
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