Clinical manifestations :

The clinical manifestations are reflections of hemodynamic derangements.

The patients will have a decreased cardiac output resulting in elevated right atrial pressure with systemic venous congestion and fluid accumulation and/or elevated left atrial pressure with pulmonary venous congestion. The compensatory sympathetic stimulation results in peripheral vasoconstriction and the peripheral blood flow is redistributed in favor of the vital organs.

Since these hemodynamic changes may occur separately and not at the same time, the clinical manifestations of heart failure may vary a great deal between patient to patient.

Impaired myocardial function results in cardiomegaly, tachycardia, gallop rhythm, poor peripheral perfusion and growth retardation.

Cardiomegaly occurs in all patients with CHF except in pulmonary venous obstruction and constrictive pericarditis.

A sleeping heart rate above 160/min in infants and above 100/min in children is always present in CHF. A protodiastolic gallop at the time of rapid ventricular filling is a sign of impaired ventricular function.

Poor peripheral perfusion manifests itself by cold extremities, weak pulses and low blood pressure associated with skin mottling.

Growth retardation is noted in all infants with chronic CHF.

Dyspnea and tachypnea are typical signs of increased pulmonary venous pressure. Respiratory rates may be as high as 80-100/min and are associated with retraction, grunting and poor feeding.

Wheezing may be earliest and occasionally only evidence of pulmonary edema.

Rales are relatively uncommon sign of pulmonary edema in the pediatric age group.

Cyanosis , in the absence of intracardiac R -> L shunt, may be present and is secondary to impaired pulmonary gas exchange as well as due to sluggish peripheral circulation.

Signs of systemic venous congestion include hepatomegaly- if it is 2 cm or more below right costal margin in the mid clavicular line and tender, then it suggests failure due to overloading of right ventricle. There is peripheral edema involving pretibial, sacral and periorbital areas.

Table II - Clinical manifestations of CHF

Cardiomegaly	Failure to thrive
Tachycardia	Wheezing
Tachypnea, dyspnea	Gallop rhythm
Peripheral edema	Rales
Hepatomegaly	Peripheral cyanosis
Sweating	Poor pulses

Laboratory studies :

It is to be remembered that CHF is a clinical syndrome and is not associated with a diagnostic laboratory test.

The X ray chest PA view shows cardiomegaly and increased pulmonary vascular markings. Normal sized heart is incompatible with diagnosis of CHF except in anomalous pulmonary venous return with constriction and constrictive pericarditis.

The electrocardiograph is not diagnostic of CHF except in CHF secondary to tachyarrhythmias.

Echocardiogram with decreased ejection fraction and low circumferential fibre shortening are direct evidence of heart failure. In addition, it differentiates systolic or diastolic dysfunction as a cause of CHF. Also it is helpful in the diagnosis of pericardial effusion.

A mild degree of anemia and moderate leukocytosis are observed in CHF.

Renal function test reveal evidence of decreased glomerular filtration rate and decreased urine output. BUN and creatinine may be elevated. Urine analysis shows proteinuria and microscopic hematuria.

Differential Diagnosis (Table III) :

While the diagnosis of CHF is readily accomplished in older children, it can be difficult in infants because typical cardiac findings may be absent or obscured by pulmonary disease. Also characteristic heart murmurs may not be audible in severe CHF, because of reduced cardiac output.

Table III - Differential Diagnosis of CHF

Respiratory Distress Syndrome	Hypoglycemia
Acute bronchiolitis	CNS disorder
Pneumonia	Polycythemia
Sepsis	Renal disease