Ann M. Dietrich, Leslie Mihalov, and Katherine Mizelle
Congenital heart disease occurs in nearly 1% of live-born infants and must be recognized as early as possible in order to guide definitive medical and surgical management. At least 15% of congenital heart defects (CHDs) are associated with genetic conditions and about 20% to 30% of people with a CHD have other physical, developmental, or cognitive disorders (1). Routine neonatal examination fails to detect over half of infants with congenital heart disease. Many are discharged from the nursery before having a diagnosis made, and almost one-third of infants with critical heart lesions present to medical attention during the first week of life at the time of closure of the ductus arteriosus (2). Initial presentations range from the subtle (poor feeding) to the fulminant (shock or profound cyanosis), making congenital cardiac disease an important consideration in the differential diagnosis of any ill infant or young child. Congenital cardiac lesions can be classified by their mode of presentation and for the purposes of this chapter will be discussed in the following order: (1) cyanotic heart disease, (2) acyanotic heart disease, and (3) congestive heart failure (CHF).
CYANOTIC HEART DISEASE
CLINICAL PRESENTATION
Cyanosis is relatively infrequent in pediatric patients and is more commonly due to lung disease than heart disease. Cardiac lesions leading to cyanosis result from one of the three mechanisms: (1) obstruction of blood flow to the pulmonary circulation, (2) return of deoxygenated systemic blood back to the systemic circulation without passing through the lungs, or (3) inability of pulmonary venous blood to return to the left atrium and thence to the systemic circulation.
It is vital to differentiate between peripheral cyanosis (acrocyanosis, or discoloration of the extremities), which is particularly common in neonates (e.g., in a cold child or in a child with decreased peripheral perfusion), and central cyanosis (likely secondary to central nervous system depression, pulmonary disease, sepsis, metabolic disease, toxic ingestion, or cardiac disease).
The most common causes of cyanotic congenital heart disease are transposition of the great arteries (TGA), tetralogy of Fallot (TOF), tricuspid atresia, and obstructed total anomalous pulmonary venous return (TAPVR). Pulmonary atresia/critical stenosis and truncus arteriosus may also cause cyanotic congenital heart disease, but are less common and not discussed here. Table 268.1 lists typical radiographic and electrocardiographic findings in patients with cyanotic congenital heart disease.
TABLE 268.1
Cyanotic Congenital Heart Disease
ED EVALUATION
The underlying physiology and presentations of cyanotic heart lesions, while seemingly complex, relies heavily on appreciating the importance of maintaining communication between the right- and left-sided circulatory systems in ductal-dependent lesions. Finally, the majority of children living with cyanotic heart disease as they progress through the course of multiple procedures have room air oxygen saturations of <90%. It is important to query caregivers about the patient’s baseline oxygen saturations to have an informed sense of how to stratify the severity of a patient’s current presentation (Table 268.1)
Transposition of the Great Arteries
TGA is the most common cyanotic congenital heart lesion to present in the neonate, and the second most common cyanotic congenital cardiac abnormality (6). It accounts for 5% of all congenital heart disease, and is more common in males. In a heart with D-transposition of the great vessels, the pulmonary and systemic circulations are isolated and in effect independent of one another, making a connection between the two systems via either an atrial/ventricular septal defect (ASD/VSD) or a patent ductus arteriosus (PDA) critical for survival.
Patients typically present in the newborn period with cyanosis and tachypnea but are not generally dyspneic. On auscultation, there is a loud, single S2. A systolic murmur may also be appreciated if an associated VSD is present or if there is pulmonary stenosis. Radiographically, TGA may present with mild cardiomegaly and increased pulmonary vascular markings, with a narrowed mediastinum (“egg on a string” appearance), but the majority of newborns with TGA have a normal-appearing chest x-ray. The electrocardiogram (ECG) is generally not diagnostic, showing the expected rightward axis and prominent right ventricular forces seen in neonates.
Management focuses on stabilization and allowing mixture of blood between the two circulatory systems. A prostaglandin E1 (PGE1) infusion can improve oxygenation by opening the ductus arteriosus to allow bidirectional mixture of the blood (see ED Management). Early involvement by a pediatric cardiologist is critical. Patients may require an emergent procedure for stabilization, such as a Rashkind atrial balloon septostomy, followed by definitive operative repair. Operations used for TGA include the Mustard, Senning, and arterial switch procedures. The arterial switch procedure is preferable because the right ventricle functions poorly as a normal systemic ventricle as the child ages, and there is a higher incidence of arrhythmias with procedures dependent on intra-atrial baffle procedures. To date, survivors of the arterial switch operation have much lower morbidity.
Tetralogy of Fallot
TOF is the most common form of cyanotic congenital heart disease beyond early infancy, representing 6% to 10% of all children with a CHD. Males and females are affected equally. The four defects comprising the tetralogy are: (1) VSD, (2) pulmonary stenosis, (3) right ventricular hypertrophy, and (4) overriding aorta.
In the newborn period patients typically present with a murmur. Clinical symptoms depend on the degree of right ventricular outflow tract (RVOT) obstruction. Initially, most infants are asymptomatic and only mildly cyanotic. As the RVOT obstruction progresses, the infant becomes increasingly cyanotic. Only about 25% of infants with TOF are markedly cyanotic at birth, and this subset can present in the first few days of life with acidosis due to severe cyanosis as a result of closure of the ductus arteriosus. On physical examination, the infant may have a right ventricular heave on palpation, a single S2 (pulmonic valve closure not heard), and a systolic ejection murmur at the left mid to upper sternal border (the intensity of which varies inversely with the degree of RVOT obstruction). A continuous murmur due to a PDA or collateral vessels may also be present. An ECG will generally demonstrate right axis deviation and right ventricular hypertrophy. A chest radiograph characteristically shows a normal heart size with decreased pulmonary vascular markings, and a deficient main pulmonary artery segment resulting in a “boot shape” appearance of the heart.
Cyanotic or hypoxemic episodes “tet spells” are seen in some patients with TOF and typically consist of hyperpnea, irritability, and increasing cyanosis along with a decreased intensity of the underlying heart murmur. These episodes are frequently initiated by crying, and can also be precipitated by acute hypovolemia and tachycardia. During a “tet spell,” the murmur of pulmonary stenosis will markedly decrease in intensity. A decrease in systemic vascular resistance along with increased resistance to flow across the RVOT increases the right-to-left shunting across the VSD, which causes hyperpnea; the subsequent, increase in systemic venous return further promotes an increase in right-to-left shunting (see ED Management).
All patients with TOF will ultimately require surgical intervention. In a very young infant with severe RVOT obstruction and recurrent “tet spells,” palliative surgery to augment pulmonary blood flow involves surgical placement of a shunt, either a Blalock–Taussig shunt (subclavian artery to the ipsilateral pulmonary artery, or a central shunt [aorta to pulmonary artery]). Definitive surgical repair includes patch closure of the VSD and relief of the right ventricular outflow obstruction. A Rastelli procedure may be necessary in patients whose anatomy requires a conduit to bypass the RVOT obstruction.
Tricuspid Atresia
Tricuspid atresia has an incidence of 1% to 2% with no gender predominance. Children with tricuspid atresia, in addition to a missing valve, have a variable degree of underdevelopment of the right ventricle and pulmonic valve. Associated lesions include a VSD, pulmonary stenosis, and transposition of the great vessels. As there is no flow from the right atrium into the right ventricle, an ASD as well as a VSD are critical for survival in the newborn. If there is significant pulmonary stenosis present, a PDA is necessary to ensure adequate pulmonary blood flow. Common presentations include severe cyanosis, poor feeding, and tachypnea. On physical examination there is a single S2, but patients with an accompanying VSD will have a grade 2–3/6 systolic murmur best heard at the left lower sternal border. Severe pulmonary stenosis will present with a loud systolic ejection murmur at the left upper sternal border. If a PDA is also present, the patient may have a continuous murmur and if there is obstruction to flow across the ASD, the infant will likely have hepatomegaly. The ECG has a characteristic leftward and superior QRS axis, along with evidence of right atrial and left atrial hypertrophy (RAH and LAH), as well as left ventricular hypertrophy. The chest radiograph will show a normal to slight increase in heart size along with decreased pulmonary vascular markings. Like all patients with abnormal development of two ventricles, these patients need multiple palliative surgeries to normalize oxygenation levels.
Ebstein Disease
Ebstein disease is a rare cause of cyanotic congenital heart disease, and consists of malformation of the septal and posterior leaflets of the tricuspid valve. Severe Ebstein disease presents in the neonate with marked cyanosis and tachypnea. The lesion is characterized on examination by a split S1, a triple or quadruple gallop, and a systolic murmur along the left mid to lower sternal border from severe tricuspid valve regurgitation. In severely cyanotic neonates, management consists of PGE1 to keep the ductus arteriosis patent until pulmonary vascular resistance decreases after infancy. Surgery in infancy is reserved for patients with persistent severe cyanosis and acidosis. After infancy, patients are generally asymptomatic with a variable degree of cyanosis. The ECG is notable for marked right atrial enlargement, and a right bundle branch block. Pre-excitation is seen in up to 25% of patients. The chest radiographic is pathognomonic, with massive cardiomegaly from right atrial dilation, and decreased pulmonary vascular markings.
Total Anomalous Pulmonary Venous Return
In TAPVR, the pulmonary veins bring the blood from the lungs to the right atrium instead of the left atrium. This entity may be divided into four anatomic groups, depending on the course of pulmonary venous drainage: (1) supracardiac, (2) cardiac, (3) infracardiac, and (4) mixed types. Patients with infracardiac drainage generally have significant pulmonary venous obstruction, and present with severe cyanosis and respiratory distress. In addition to pallor and decreased pulses due to decreased cardiac output, there is frequently hepatomegaly. The cardiac examination tends to reveal a loud single S2 with a gallop rhythm. The ECG demonstrates sinus tachycardia, right axis deviation, and right ventricular hypertrophy. A chest radiograph will show a small cardiac silhouette with pulmonary edema due to pulmonary venous congestion. Obstructed TAPVR is a surgical emergency, and immediate stabilization and repair is indicated.
KEY TESTING
• The hyperoxia test in patients with undifferentiated congenital disease
• Chest radiograph
• ECG
• Echocardiogram if available
ED MANAGEMENT
The initial management should focus on stabilization of the airway, breathing, and circulation. Once a diagnosis of congenital heart disease is suspected, a call to a tertiary care center, pediatric ED, or pediatric cardiologist is appropriate. If the child has a suspected ductal-dependent lesion, a PGE1 infusion should be initiated at a rate of 0.05 to 0.1 μg/kg/min. Adverse effects associated with PGE1 infusions include apnea (12%), fever, hypotension, and seizures. Because of the frequent occurrence of apnea, elective intubation should be considered prior to initiation of the PGE1 infusion.
The hyperoxia test. This is a useful bedside test to determine the etiology of a child’s cyanosis (respiratory vs. cardiac). With the application of 100% oxygen, an increase in pO2 to >100 mm Hg suggests pulmonary disease, whereas a pO2 <100 mm Hg suggests cyanotic congenital heart disease. The test can also be performed by measuring the oxygen saturation before and after the application of 100% oxygen, although this can be misleading because pulse oximetry is not as consistently accurate. The oxygen saturation should increase by at least 10% in the presence of a pulmonary process.
In patients with TOF and a hypercyanotic spell, a variety of maneuvers to improve oxygenation should be performed emergently. The child may benefit from being placed in the knee-to-chest position. All children should receive supplemental oxygen. Morphine sulfate at a dose of 0.1 mg/kg intramuscularly or subcutaneously may be given. IV access should be established, as these children are at high risk for recurrent episodes. An IV fluid bolus of 10 to 20 mL/kg may then be given. In refractory cases, phenylephrine 0.02 mg/kg IV should be considered to increase systemic vascular resistance and promote pulmonary blood flow. The dose may need to be titrated for effect. Sodium bicarbonate and propranolol may also be effective. In completely unresponsive cases, general anesthesia and paralysis may be considered. These children invariably require urgent surgical intervention.
ACYANOTIC HEART DISEASE
CLINICAL PRESENTATION
Acyanotic cardiac disease is composed primarily of lesions causing left to right shunting and left ventricular outflow tract (LVOT) obstructions. Lesions causing acute left to right shunting comprise almost 50% of all congenital heart disease and include (1) VSDs, (2) ASDs, (3) PDA, and (4) endocardial cushion defects. Infants with significant LVOT obstruction generally present in the first few weeks of life with symptoms of shock due to inadequate cardiac output after closure of the ductus arteriosus. The timing of presentation of a left-sided obstructive lesion depends upon the degree of obstruction and upon ventricular function. The most common lesions presenting emergently are: (1) critical aortic stenosis, (2) critical coarctation of the aorta, (3) interrupted aortic arch (IAA), and (4) hypoplastic left heart syndrome (HLHS).
ED EVALUATION
Left–Right Shunts due to Structural Lesions
Depending on the degree of shunting from the systemic to the pulmonary side, consequences of significant pulmonary overcirculation can develop, including left ventricular dilation and hypertrophy, decreased ventricular function, and signs of CHF. In the neonate, high pulmonary vascular resistance initially limits the amount of left-to-right shunting, but as pulmonary vascular resistance drops in the first few weeks of life, pulmonary blood flow increases. Large left-to-right shunts (except ASDs) will eventually result in the development of pulmonary hypertension and the Eisenmenger complex if not diagnosed and surgically repaired in a timely fashion.
Clinically, patients will have a murmur characteristic of a specific defect. There is frequently a diastolic rumble or gallop. Pulmonary overcirculation may be the cause of the patient’s tachypnea (with or without respiratory distress), pallor or mottling of the extremities, and underlie a history of feeding difficulties and poor weight gain. The differential diagnosis should include sepsis; however, the distinguishing features of the heart murmur, an S3 gallop, and enlarged heart on chest radiograph will help identify CHF in patients with shunt lesions. Pulse oximetry may demonstrate mildly decreased oxygen saturations due to pulmonary edema. Supplemental oxygen therapy should be used judiciously since it can accelerate CHF symptoms by lowering pulmonary vascular resistance and further enabling pulmonary blood flow.
Left-Sided Obstructive Lesions
Critical Aortic Stenosis and Critical Coarctation of the Aorta
The age of presentation of patients with aortic valve stenosis (AS) depends on the severity of the obstruction to flow across the aortic valve. Approximately 10% to 15% of patients present before 1 year of age (4). The typical presentation of severe aortic stenosis in infancy is CHF, but there can be cardiogenic shock in the setting of critical AS (ductal-dependent systemic blood flow). The latter patients present acutely and appear ashen, with markedly decreased or absent pulses, and are severely acidotic and obtunded. These patients may be cyanotic due to pulmonary venous desaturation. The classic murmur of AS is typically a loud and harsh systolic murmur with transmission to the neck. Patients presenting with severe aortic stenosis may have minimal, if any, murmur because of associated diminished cardiac output from ventricular dysfunction. Patients with reasonable cardiac output and aortic stenosis may also have an ejection click and a systolic thrill in the region of the upper right sternal border, suprasternal notch, or carotid arteries.
Infants with critical coarctation generally present before 2 weeks of age owing to progressive ductal closure and manifestations of obstructed arterial flow, whereas older children and adolescents with less severe coarctation may present with a murmur and hypertension that may have been longstanding in nature. Unlike patients with critical aortic stenosis who present with diminished pulses throughout, patients with severe or critical coarctation of the aorta and IAA should have unequal upper and lower extremity pulses (higher in the upper extremities). Four-limb blood pressures can be diagnostic. Simultaneous pulse oximetry readings in the right hand and a foot in patients with coarctation may show significantly lower oxygen saturation in the foot, due to perfusion of the lower extremities with desaturated blood from the PDA. A pulse oximetry reading in the leg of <92% on room air or more than a 7% difference between the leg and arm was found in 85% of infants with left heart obstructive disease and in 79% with other forms of congenital heart disease (5,6). ECG findings in critical aortic stenosis and critical coarctation are similar, with biventricular hypertrophy, ST-segment changes, and inverted T waves in lead V6.
The radiographic findings of patients with left-sided obstructive lesions vary. Infants who present in failure may have cardiac dilation and pulmonary venous congestion. Older children with aortic stenosis generally have a normal-appearing chest x-ray, and those with isolated coarctation of the aorta can have evidence of collateral blood vessels, characterized by rib notching.
Hypoplastic Left Heart Syndrome
HLHS accounts for 1% of all CHDs, and is more common in males. As in infants with critical coarctation of the aorta and critical aortic stenosis, systemic perfusion depends on a PDA. Clinical presentation after birth can initially be subtle, with no murmur, intermittent pallor, and a complaint that the infant is “not acting right.” As the ductus constricts, tachypnea, respiratory distress, and metabolic acidosis occur. The closure of the ductus results in rapidly progressive cardiogenic shock and circulatory collapse. In addition, there can be significant obstruction to systemic blood flow if there is restriction of the obligatory left-to-right shunt across the patent foramen ovale. Surprisingly, infants with HLHS may have normal radiographic findings. ECG findings vary considerably but commonly there is RVH.
ED MANAGEMENT
The initial management should focus on acute stabilization of the airway, breathing, and circulation. Once a diagnosis of congenital heart disease is suspected, a call to the tertiary care center, pediatric ED, or pediatric cardiologist is indicated. Management of symptomatic shunt lesions is discussed in the next section on CHF. If there is concern regarding a left-sided obstructive lesion, initiation of PGE1 at 0.05 to 0.1 μg/kg/min may help to maintain patency of the ductus in an infant. The goal should be to maintain adequate systemic blood flow via the ductus without hyperperfusing the pulmonary vasculature. This balance can be achieved by methods to increase the pulmonary vascular resistance, such as controlled hypoventilation and positive end-expiratory pressure.Supplemental oxygen should be limited, with acceptance of lower oxygen saturations, to avoid a dramatic drop in pulmonary vascular resistance. Sodium bicarbonate may be indicated in patients with severe acidosis. Prompt referral to a pediatric cardiologist or pediatric cardiovascular surgeon is indicated. Treatment may include staged or definitive surgery, or interventional cardiac catheterization (e.g., for aortic stenosis).
CONGESTIVE HEART FAILURE
CLINICAL PRESENTATION
Ninety percent of cases of CHF in children occur during the first year of life and it is frequently the final common pathway for congenital lesions that have progressed to critical stages. The CHDs most commonly associated with CHF are those that result in pulmonary overcirculation through a large left-to-right shunt (VSD, PDA, atrioventricular [AV] canal defect). Patients with significant shunts typically present between 3 and 8 weeks of age, following the physiologic drop in pulmonary vascular resistance, which allows pulmonary overcirculation to develop. The pathophysiology of CHF in these children starts with increased pulmonary blood flow and progresses to pulmonary interstitial edema, and volume overload of the left heart. A chest radiograph should be considered for any “first-time wheezer” who fails to improve with conventional treatment. Hyperinflation from bronchiolitis should be associated with a normal or small cardiac silhouette. Cardiomegaly in a child with wheezing suggests “cardiac asthma” due to cardiomyopathy, pericardial effusion, pulmonary overcirculation, or other cardiac etiologies. Children presenting with symptoms of CHF later in life should be suspected of having an acquired problem (e.g., cardiomyopathy) rather than a congenital heart disease. In contrast, CHF in the first day of life is usually secondary to cardiac muscle dysfunction from hypoxia, hypoglycemia, hypocalcemia, myocarditis, sepsis, or infarct (e.g., from an anomalous left coronary artery).
Left-to-right shunt lesions with pulmonary overcirculation, and some left ventricular outflow obstructive lesions, should be appropriately identified based on history, physical examination, and the timing of clinical presentation. Infants with CHF typically present with tachypnea, tachycardia, and diaphoresis. Because the bulk of work performed by infants and small children occurs during feeding, many of these children also have feeding intolerance and failure to thrive. Toddlers and older children usually have tachycardia, tachypnea, fatigue, and exercise intolerance. In older children, peripheral edema and venous distension may be apparent, but they are unusual and are associated with significant right-sided heart failure. Physical examination findings of CHF may include hepatomegaly and a gallop rhythm, with decreased peripheral pulses. On chest x-ray, there is typically cardiac enlargement and increased pulmonary vascular markings, with pulmonary edema. Significant cardiomegaly in the absence of pulmonary vascular congestion should raise suspicion of pericardial effusion.
ED EVALUATION
Structural Congenital Heart Defects
Cardiomyopathy and Myocarditis
Clinical signs of diminished cardiac output and CHF may occur in patients with poor myocardial function due to cardiomyopathy or myocarditis. A cardiomyopathy can be the result of ischemia due to a coronary artery anomaly, a glycogen storage disease, a previous viral infection, muscular dystrophy, an inherited or idiopathic myopathy, or incessant tachyarrhythmia. The degree of symptomatology is usually related to the degree and duration of cardiac dysfunction. The patient with mild dysfunction may present with only mild symptoms of tachypnea and poor feeding (or weakness and fatigue in older patients), whereas the patient with end-stage cardiomyopathy may present in florid CHF and require emergent resuscitation. The child with acute myocarditis may present with severe cardiac dysfunction and an associated tachyarrhythmia (e.g., sinus tachycardia, premature ventricular contractions, ventricular tachycardia) or bradyarrhythmia (e.g., second- or third-degree heart block).
The classic radiographic findings in these patients include cardiomegaly and, frequently, pulmonary edema. Patients with sustained tachyarrhythmias can have cardiac enlargement as a result of LV failure. Patients with a “dilated,” poorly functioning cardiomyopathy may show ECG findings of atrial enlargement, LVH, and occasionally RVH, in addition to, ST-segment or T-wave changes. Children with glycogen storage diseases, such as Pompe disease, may have a short PR interval with very large precordial QRS voltages. Decreased amplitude, manifested as a low-voltage QRS (<5 mm total in each frontal lead), suggests myocarditis with decreased contractility or restrictive disease. One also must consider a large pericardial effusion as the cause for low QRS voltage. Patients with an anomalous left coronary arising from the pulmonary artery may have ECG evidence of an ST elevation myocardial infarction (STEMI).
ED MANAGEMENT
In general, the treatment of CHF includes both respiratory and inotropic support. CHF cannot be treated the same in all pediatric patients, due to the wide variety of potential etiologies (7). Infants with cardiogenic shock and septic shock can present similarly, with poor perfusion and metabolic acidosis. However, septic shock requires fluid resuscitation and possibly vasopressors, whereas cardiogenic shock often requires the use of PGE1 infusion.
The approach in the acute care setting should be as follows: (1) to remove any precipitating or aggravating factors (i.e., transfuse for severe anemia, treat dysrhythmias, and possibly restrict fluids), (2) to reduce metabolic demands (reduce fever, sedate agitated patients, consider endotracheal intubation and ventilation), (3) to relieve pulmonary congestion (diuresis, mechanical ventilation with positive end-expiratory pressure, morphine sulfate), and (4) to improve myocardial performance and oxygen delivery (inotropes, afterload reduction, preload reduction, oxygen [which must be used carefully since it can worsen pulmonary overcirculation], PGE1 [specifically for ductal-dependent left heart obstructive lesions] and correction of metabolic acidosis). In the acute care setting dobutamine and the phosphodiesterase inhibitor milrinone have been successfully used. Dobutamine should be initiated as a continuous infusion at 5 to 10 μg/kg/min. Low-dose dopamine (3 to 6 μg/kg/min) may also be of assistance by promoting diuresis. Milrinone has gained favor in the management of children with myocardial dysfunction; its major advantage is the lack of chronotropic stimulation while assisting with afterload reduction. However, proarrhythmic effects have been reported. Agents such as epinephrine and norepinephrine can be used in the patient with ventricular dysfunction; however, they may aggravate the sympathetic overstimulation of fulminant CHF and also are proarrhythmic.
If the etiology of low cardiac output appears to be poor myocardial function, the initial focus should be on maximizing oxygenation and improving cardiac output through inotropic support, including afterload reduction. In addition, oxygen consumption should be minimized via maintenance of normothermia, normal hemoglobin levels, and preventing or reversing tachycardia.
Unique Complications of Pediatric Congenital Heart Disease
Children with congenital heart disease are at risk for unique complications. Patients with baseline limited pulmonary blood flow are extremely sensitive to acute alterations in pulmonary vascular resistance, and simple respiratory infections (e.g., acute bronchiolitis) are potentially life-threatening in this subset of patients. Patients with defects that limit pulmonary or systemic blood flow require close monitoring for common viral illnesses, such as viral gastroenteritis, as they typically do not tolerate dehydration well.
The Fontan procedure may be performed palliatively in children with complex CHDs. In this staged procedure, systemic venous blood is diverted to the pulmonary arteries without passing through the right ventricle. These patients are at increased risk for pulmonary embolism and for a protein-losing enteropathy that may present with ascites, peripheral edema, and pleural effusions. Patients with shunt-dependent lesions (e.g., pulmonary atresia with a systemic-to-pulmonary shunt) may present with sudden and severe cyanosis and acidosis (and an absence of a continuous shunt murmur on physical examination) owing to thrombotic obstruction of the shunt. Patients with existing right-to-left shunts (either pre- or postoperative) are at risk for stroke, particularly children with polycythemia or chronic cyanosis. These children should have filters on all IV lines to decrease the risk of air emboli. Finally, all children with known cyanotic or complex structural heart disease, or those who have had prosthetic materials inserted, are at increased risk for bacterial endocarditis.
A patient who has had surgery involving the atrium, including the Mustard and Senning operation, is at risk for atrial tachyarrhythmias and sinus node dysfunction. Unlike the typical atrial flutter seen in adults, these patients can manifest atrial tachycardia at a wide range of rates. Ventricular tachycardia is a significant risk of morbidity and mortality in patients with previous ventriculotomy, especially patients with a previous repair of TOF.
CRITICAL INTERVENTIONS
• In addition to congenital heart disease, consider sepsis in a child with poor perfusion and cyanosis.
• Timely prostaglandin infusion for suspected cyanotic ductal-dependent lesions, presenting most commonly within the first week of life. Benefits outweigh the risks even if there is ultimately no cardiac lesion.
• Use supplemental oxygen judiciously in patients where pulmonary vascular resistance must be considered as part of the hemodynamics of an obstructive left-sided lesion.
• Differentiate cardiac from respiratory disease via the hyperoxia test when indicated.
DISPOSITION
Patients with acute problems related to congenital heart disease almost universally require emergent cardiology consultation or critical care admission. If patients are not at a tertiary pediatric center with cardiologic expertise, use of a Neonatal/Pediatric Critical Care Transport Team may be indicated.
Common Pitfalls
• Failure to recognize that cardiogenic shock and septic shock can present similarly, with poor perfusion and metabolic acidosis. Septic shock requires fluid resuscitation and possibly vasopressors, whereas cardiogenic shock in infancy often requires the use of PGE1 infusions.
• Failure to consider a potential cardiac etiology in infants presenting with complaints that include poor feeding, lethargy, dehydration, or septic appearance.
• Delay in institution of prostaglandin infusion.
REFERENCES
1. Miller A, Riehle-Colarusso T, Alverson CJ, et al. Congenital heart defects and major structural noncardiac anomalies, Atlanta, Georgia, 1968–2005. J Pediatr. 2011;159:70–78.
2. Chang RK, Gurvitz M, Rodriguez S. Missed diagnosis of critical congenital heart disease. Arch Pediatr Adolesc Med. 2008;162:969–974.
3. Grifka R. Cyanotic congenital heart disease with increased pulmonary blood flow. In: Berger S, ed. The Pediatric Clinics of North America. Philadelphia, PA: WB Saunders; 1999:405–425.
4. Fedderly R. Left ventricular outflow obstruction. In: Berger S, ed. The Pediatric Clinics of North America. Philadelphia, PA: WB Saunders; 1999:369–384.
5. Bakr AF, Habib HS. Combining pulse oximetry and clinical examination in screening for congenital heart disease. Pediatr Cardiol. 2005;26:832–835.
6. Hoke TR, Donohue PK, Bawa, PK, et al. Oxygen saturation as a screening test for critical congenital heart disease: A preliminary study. Pediatr Cardiol. 2002;23(4):403–409.
7. Kantor PE, Lougheed J, Dancea A, et al. Presentation, diagnosis and medical management of heart failure in children: Canadian Cardiovascular Society guidelines. Can J Cardiol. 2013; 29(12):1535–1552.