Howard P. Gutgesell and George M. McDaniel
HISTORY
For the cardiovascular system, a thorough history should be performed at 2 levels: the general review of systems at all well-child and illness visits and a more comprehensive history when a cardiovascular disorder is suspected.
In infants and younger children, review of feeding and respiration may point to a cardiovascular disorder. Feeding is the stress test of infancy. Rapid breathing or retractions while feeding or failure to gain weight may indicate cardiac disease. In older children, exercise intolerance, light-headedness, syncope, or chest pain may suggest an underlying cardiac abnormality. All these symptoms, however, are common in the general population, and further history, physical examination, and laboratory tests are frequently necessary to determine the cause.
If the patient’s presentation, screening history, or physical examination suggest a possible cardiovascular disorder, a more detailed cardiovascular history is warranted. Examples include the critically ill patient with shock or respiratory distress, the preschool or adolescent child with a newly detected heart murmur, and the child complaining of chest pain, exercise intolerance, palpitations, or syncope. A more detailed history should include any issues during the pregnancy and neonatal period, growth and development during early childhood, and family history, as well as the current complaint. Specific areas include the following:
• pregnancy and neonatal history (eg, maternal diabetes or systemic lupus erythematosus, maternal medications, need for supplemental oxygen after birth, and neonatal illnesses)
• infancy (eg, feeding difficulties, failure to thrive, cyanosis, and respiratory distress)
• children and adolescents (eg, lack of peer-appropriate exercise tolerance, syncope, chest pain)
• family history (eg, congenital heart abnormalities in close relatives, sudden death or premature “heart attacks,” chromosomal abnormalities in parents or other family members).
PHYSICAL EXAMINATION
The cardiovascular examination should be systematic. Cardiac disorders are seldom missed because the examiner could not distinguish a grade 2 from a grade 3 murmur, but rather because a major portion of the examination was overlooked (eg, failure to measure blood pressure or confirm the presence of pulses in the lower extremity in patients with coarctation of the aorta).1 What follows is an outline of a systematic examination with reference to the particular questions to be considered at each point.
Vital signs. Are the weight, height, head circumference, heart rate, and blood pressure age-appropriate?
Head and neck. Is there cyanosis, dental caries, jugular venous distention, evidence of genetic syndrome?
Chest. Is there a skeletal deformity (pectus carinatum, pectus excavatum, straight back, asymmetric thorax), stridor, retractions, wheezes, rales?
Precordium and heart. Are there palpable heaves or thrills murmurs or extra heart sounds? What are the sites and intensity of first and second heart sounds (see below)?
Abdomen. Is the liver or spleen enlarged or are there ascites? Is abdominal situs normal?
Extremities. Are the pulses normal in all extremities, or is there cyanosis, clubbing, or edema?
EXAMINATION OF THE HEART
Examination of the heart should be done systematically and should begin with palpation of the precordium and suprasternal notch, with attention to accentuated impulses and the presence of a thrill. Auscultation of the heart should be performed at the apex, along the left sternal border (LSB), beneath the clavicles, in the axillae, and over the back. At each location one should listen to the first heart sound, any systolic murmur or extra sound, the second heart sound, and any diastolic sounds. The first heart sound is heard best at the apex and lower-LSB and should be crisp; soft first sounds suggest poor contractility or a long PR interval. The second heart sound is normally split, with the first aortic component loudest at the upper-right sternal border or equally loud at the upper-LSB. An aortic sound loudest at the upper- or mid-LSB suggests an aortic malposition. The pulmonic component of the second heart sound is heard best at the upper-LSB, and is usually softer than the aortic component unless there is pulmonary hypertension. Normally, the splitting widens with inspiration, and if it does not, an atrial septal defect should be suspected. Abnormally wide splitting occurs with an atrial septal defect, moderate or severe pulmonic stenosis, or right bundle branch block. Dull, low-pitched third or fourth heart sounds are best heard at the apex or left LSB. Systolic murmurs may be regurgitant, with even intensity from the first to the second heart sound, or ejection, which starts after the first heart sound, rises, and then falls in intensity, ending anywhere from midsystole to the second heart sound. The higher the pitch of the murmur, the higher the velocity of the jet. Diastolic murmurs are decrescendo, starting at the aortic second sound in aortic regurgitation and after a delay at the pulmonic second sound in pulmonary regurgitation. For each murmur, its site of maximal intensity and direction of radiation may be informative.
Assessment of heart murmurs is a common task for the primary care physician, and the presence of a heart murmur is the most common indication for referral to a pediatric cardiologist. Although many sources describe in detail the auscultatory features of specific cardiac lesions, cardiologists seldom base diagnosis or therapy solely on qualities of the murmur. Important findings such as persistent splitting of the second heart sound, ejection clicks, and diastolic heart sounds lead to suspicion of congenital heart lesions but are unlikely to be appreciated unless the physician has special training or interest in cardiology. It is important, however, for the primary care physician to be familiar with the common innocent murmurs that occur in most children and to know which murmurs require referral for further evaluation.2,3
The most frequently encountered innocent murmurs are discussed next.
Still Murmur Described nearly a century ago by George Frederick Still in a text about common diseases of childhood,4 this is a low-pitched, short, vibratory ejection murmur best heard over the midprecordium. It is typically heard in young children, less commonly in infants and adolescents. It is flow related and so changes in intensity from time to time, for example, during respiration, change in posture, or state of activity.
Pulmonary Flow Murmur A pulmonary flow murmur is a soft short systolic ejection murmur heard at the upper-left sternal border.
Venous Hum A venous hum is a continuous, blowing murmur heard best immediately beneath the right clavicle in patients in the sitting or standing position. It generally disappears when supine and can be abolished by gentle compression of the right jugular vein or while straining.
Physiological Peripheral Pulmonary Stenosis Murmur The term physiological peripheral pulmonary stenosis murmur is a misnomer. The left and right pulmonary arteries are not stenotic, but simply relatively small compared to the diameter of the main pulmonary artery. This, with the physiologic anemia of early infancy that is associated with an increased cardiac output, produces a soft short systolic murmur best heard in the axillae. It generally disappears by 1 year of age.
WHEN TO REFER FOR HEART MURMUR
Heart murmurs are common in childhood. The primary care physician should have a practical and consistent approach to determine which murmurs are innocent and which need referral for further evaluation. In addition to the murmur itself, factors to consider are the age of the patient, the presence of other signs or symptoms that may indicate cardiac disease, the availability of a referral center, and the anxiety of the parents. Importantly, heart disease in children may exist without a murmur, for example, with myocarditis or a cardiomyopathy or a coronary artery anomaly.
In general, murmurs caused by structural heart disease tend to be louder and occupy a greater portion of systole than do innocent murmurs. The exception is in the critically ill infant whose murmur has decreased because of low cardiac output; however, in this circumstance, there will be signs of systemic and pulmonary venous engorgement, such as hepatomegaly and tachypnea. There may be a thrill at the left sternal border from a ventricular septal defect or pulmonary valve stenosis, or in the suprasternal notch in aortic stenosis. Diastolic murmurs are uncommon and never innocent.
Younger infants are more at risk from rapid development of symptoms than are older children. For example, closure of the ductus arteriosus may precipitate cardiovascular collapse in a 2-week-old infant with coarctation of the aorta or aortic stenosis. A 1-month-old with a large ventricular septal defect may develop congestive heart failure before the next well-child visit. Conversely, an otherwise healthy 1-year-old with a soft systolic murmur is unlikely to develop cardiovascular symptoms suddenly, and the murmur may disappear by the next visit.
The general health of the patient is a more important consideration in the referral decision than trying to make a precise diagnosis from the qualities of the murmur itself. Upon detecting a murmur, it is useful to step back and ask: Is there anything about the history that, in retrospect, might indicate cardiac disease? Is the child truly asymptomatic? Is the remainder of the examination really normal? Are there normal pulses in all extremities? Is the patient normotensive?
Another consideration in the management of the child or adolescent with a murmur is whether to obtain laboratory tests to help establish a diagnosis. Chest roentgenograms are available in most practices and are valuable if abnormal, especially if they establish a pulmonary cause for respiratory symptoms. However, serious cardiac disease may be present despite a normal chest film. The electrocardiogram may be helpful (see Chapter 493). It is an excellent test for heart rate and rhythm, but has only mediocre specificity and sensitivity for detection of structural heart abnormalities. Echocardiography is now available in most community hospitals, and primary care physicians may be tempted to use it in lieu of a pediatric cardiology consultation.5 This practice should be discouraged. The technician who performs the test and the physician who interprets the results may not be adequately trained in congenital heart disease. Serious diagnostic errors have been made by such unskilled cardiologists. Perhaps the most appropriate use of the echocardiogram is in the ill patient whose condition may be managed at a community hospital if it is due to respiratory disease or infection, but who needs transfer to a tertiary care center if the illness is cardiovascular.
Finally, the comfort level of the parents is a factor in the decision to refer a patient with a murmur for further evaluation. Some parents can accept the explanation that there is a heart murmur that the child will probably “outgrow,” whereas others want a referral no matter how the primary care physician explains its presence. Pediatric cardiologists are well aware of this and do not look unfavorably upon physicians referring patients with innocent murmurs for parental considerations.
PRESENTING SYMPTOMS AND SIGNS OF CARDIAC DISEASE IN THE CHILD OR ADOLESCENT
CHEST PAIN
The complaint of chest pain in children is common. With the public media highlighting cardiac disease in the adult population and publishing tragic stories of young athletes dying suddenly on the field, it is not surprising that parents assume that any chest discomfort may involve the heart. Most chest pain is benign. In multiple studies in various settings, cardiovascular disorders have accounted for fewer than 5% of pediatric patients presenting with chest pain.6-10 Chest pain in children is most common in early adolescence; younger patients with chest pain tend to have a higher incidence of organic disease. In one study, patients under 12 were twice as likely as older children to have a cardiorespiratory cause for their complaint whereas older adolescents were 2.5 times more likely than younger children to have a psychogenic reason for the complaint.7 There is an increased incidence of chest pain in overweight children.9
There are many structures that can cause pain in the thorax. The musculoskeletal system is often implicated as the origin of pain. However, the respiratory system, cardiovascular system, gastrointestinal system, nervous system, and integument may be the culprit.
NONCARDIAC CAUSES OF CHEST PAIN
Table 486-1 lists some common noncardiac causes of pediatric chest pain.
Idiopathic
Patients presenting with idiopathic chest pain typically have a history of episodes of pain over the previous weeks to months. The pain is usually sharp, but brief. It may or may not increase with deep inspiration. There are usually no other symptoms associated with the episodes. The patients’ activities are usually not interrupted. The physical examination is normal, and the pain cannot be reproduced on the examination. Episodes can be recurrent, but do not become chronic.7
Psychogenic
Psychogenic chest pain often initially presents after an identifiable stressful event.11 The pain is usually nebulous and associated with other symptoms such as abdominal pain and headaches. Symptoms of anxiety may accompany the complaint,8 and in one report, parental anxiety was out of proportion to that of the patient.6 The typical age of onset is adolescence, and females tend to outnumber males.
Table 486-1. Noncardiac Causes of Chest Pain
Costochondritis
Costochondritis is pain and tenderness at the costochondral junction of the rib and the sternum. There is often a history of strain associated with illness and coughing or activity just prior to the onset of complaint. The pain is usually sharp in nature and can radiate. Activity tends to increase pain, as does deep breathing. Typically, the pain is unilateral and in the midsternal junctions. It is reproducible with palpation. Like other overuse injuries, recurrence is common.
Precordial Catch
The precordial catch is also known as Texidor twinge, reported in 1955 and recently reviewed.12,13 It is a very specific condition consisting of a severe sharp, stabbing, or needlelike pain at a very localized point on the chest. Episodes are brief, exacerbated by a deep breath, and occur during rest, but not during sleep. Resolution of an episode is rapid and complete. The cause of the pain is unknown, although the pleurae have been suggested as the source.
Slipping Rib
The distal 3 ribs are in fibrous continuity, but do not attach to the sternum directly. In slipping rib syndrome, one of these ribs slips over the other, creating pain. This is thought to occur as a result of trauma. The patient complains of a popping sound and pain, both of which can be reproduced by hooking the rib manually and pulling forward.14
Respiratory Diseases
Because the parietal pleura is richly innervated, pain arises when it is inflamed, irritated or injured. Acute severe chest pain accompanies spontaneous pneumothorax. The pain is sudden in onset and, depending on the amount of air in the pleural cavity and degree of lung collapse, is accompanied by dyspnea. Tension pneumothorax develops when air enters the pleural cavity during inspiration, but cannot exit from the site of lung rupture during expiration. The high pressure in the pleura and mediastinum may interfere with venous return to the heart, and it is life-threatening because cardiac output is impaired; removal of air is required immediately to relieve intrapleural pressure. Acute chest pain, characteristically occurring during inspiration, may be the result of pleuritis, result from viral infection, or be associated with bacterial pneumonia with pleural involvement; these individuals usually have fever and varying degrees of dyspnea.
Chronic chest pain may arise from pleural irritation resulting from chronic infection, such as tuberculosis. Pleuritis is also present in rheumatologic disorders, occurring in about 50% of patients with systemic lupus erythematosus. Chest pain is a frequent complaint in patients with asthma. Exercise-induced asthma is an important cause of chest pain in children. It is associated with the bronchospasm and manifests as a feeling of tightness of the chest, with acute substernal pain. It may present during exertion but often develops a few minutes after cessation of exercise and gradually improves within about 30 minutes. The association of the pain with activity or exercise often raises concern about a cardiac cause.15 Danduran and colleagues found that in patients evaluated in a cardiology clinic for chest pain, 26% had evidence of reactive airway disease with abnormal resting pulmonary function tests.9 However, two thirds of those patients had never been diagnosed with reactive airway disease.
CARDIAC CAUSES OF CHEST PAIN
Ischemic chest pain is associated with congenital coronary anomalies, vasospasm, or left-sided outflow obstruction. Ischemia can be also worsened by drugs such as bronchodilators used for asthma, because they also increase heart rate, myocardial oxygen demands, and decrease aortic diastolic pressure; thus, it may not be appropriate to ascribe all feelings of chest discomfort or pain to bronchoconstriction in patients being treated for reactive airways disease, especially those receiving high doses of medication. Patients with tachycardia also frequently complain of pain during an episode. Aortic dissection, often associated with connective tissue disorders, causes acute, chest pain in the upper chest and neck for the ascending aorta and in the back for the descending aorta. Inflammation of the pericardium often is also associated with anterior chest pain.
Coronary Artery Anomalies
Congenital coronary artery anomalies are relatively rare, but may be fatal. Those involving anomalous origin of a coronary artery from the pulmonary artery usually present early in life when pulmonary vascular resistance falls, decreases coronary perfusion pressure, and causes myocardial ischemia (so-called myocardial steal). Infants present with fussiness and diaphoresis associated with feeding, but older patients may have exertional chest pain, syncope, or simply a continuous murmur. If a coronary artery arises anomalously from the wrong (ie, ectopic) sinus of Valsalva, it may cause myocardial ischemia or even sudden death.9 Thus, a careful history is important, and a thorough cardiovascular evaluation is necessary when chest pain occurs during or immediately after exercise. The electrocardiogram and cardiac biomarkers such as troponin may be normal between episodes. Although congenital coronary anomalies can be detected by echocardiography, this requires a meticulous examination by sonographers familiar with coronary anomalies.
Vasospasm
Vasospasm has been the working diagnosis in several reports where adolescents presented electrocardiograph and enzyme changes consistent with myocardial infarction.6 The patients typically have crushing and unrelenting chest pain with cardiac gallops and murmurs of mitral regurgitation. Often there are no predisposing factors for coronary artery disease. On catheterization, the coronaries are patent. It is essential to evaluate for sympathomimetic drug abuse, especially cocaine, which can cause myocardial ischemia from coronary vasospasm and increased myocardial oxygen demand.16
Kawasaki Disease
Kawasaki disease (see Chapter 488) is a diffuse vasculitis involving the coronary arteries. It may result in giant aneurysm formation with subsequent risk of thrombosis or rupture.17 Therefore, a history of Kawasaki disease or a prolonged febrile illness with skin rash should raise suspicion of a possible cardiac origin in patients presenting with chest pain.
Left Ventricular Outflow Obstruction
In left ventricular outflow obstruction, there may be insufficient coronary blood flow as a result of a fixed obstruction at the level of the aortic valve or supravalvular area. With hypertrophic cardiomyopathy there is a mixture of a fixed component and a dynamic component in the subaortic area. The dynamic component worsens with decreased LV filling and increased contractility. Findings on physical examination include a hyperdynamic apical impulse, a harsh systolic ejection murmur (often with radiation to the suprasternal notch), and in some an apical murmur of mitral regurgitation.
Tachycardias
(See Chapter 485.) Some patients report chest pain during episodes of tachycardia. The cause of the pain is unclear and it may be a younger child’s way of describing palpitations or dyspnea. Episodes generally start and stop suddenly. They may be related to activity or occur at rest. Other symptoms such as dizziness or shortness of breath may accompany the episode. If the patient has returned to normal rhythm, the physical examination will likely be normal. The diagnosis is most often established by ambulatory electrocardiographic monitoring.
Aortic Dissection
Aortic dissection in pediatric patients is usually related to trauma or connective tissue disease. Patients with connective tissue disease such as Marfan, Ehlers-Danlos, and Turner syndromes and with a bicuspid aortic valve are at increased risk due to abnormal connective tissue in the media of large arteries. As the aorta enlarges, wall tension increases and may result in dissection or rupture. Patients describe severe, tearing chest pain, often in combination with respiratory distress, diminished peripheral pulses, and shock. Thus, any chest pain in patients with the above conditions must be taken very seriously and regarded as a potential medical emergency.
Pericarditis and Myocarditis
(See Chapters 489, 491.) Inflammation of the pericardium and adjacent myocardium typically causes anterior chest pain. Pericarditis is often associated with a viral illness, trauma, or uremia. The pain may be relieved by sitting upright and leaning forward. The patient is usually febrile, uncomfortable, and even toxic appearing. There may be a friction rub unless there is a large effusion. With a large effusion or diffuse myocarditis, the cardiac sounds are distant or muffled. Respiratory distress, hepatic enlargement, and pulsus paradoxus indicate cardiac tamponade. The diagnosis is usually made by echocardiography. Pericardiocentesis may be life-saving in cardiac tamponade.
DIAGNOSIS AND TREATMENT
Most pediatric chest pain is benign and the etiology can often be determined with a complete history and physical examination. Repeated studies have found little utility in extensive testing in the absence of an abnormality on the basic evaluation. In rare but potentially life-threatening conditions, there are almost always abnormalities on initial history and physical examination that point toward the diagnosis. The challenge for the physician is to provide reassurance to anxious patients and parents that most pediatric chest pain is benign and self-limited, while at the same time keeping an open mind to rare but life-threatening disorders. If needed, any treatment is directed at the specific cause.
SYNCOPE
Syncope is the temporary, often brief, loss of consciousness and postural tone caused by an abrupt decrease in cerebral blood flow. Typically, there is a prodromal component, including dizziness, nausea, diaphoresis, weakness, and loss of vision beginning in the periphery; a rushing sound in the ears is common. The patient usually recovers without intervention and without neurologic sequelae. Fortunately, most syncope is benign, but 1% to 2% of patients have significant underlying pathology.18-20 Syncope can occur at any age, but the typical age of onset is adolescence.18,21
PATHOPHYSIOLOGY
A simple faint, called neurocardiogenic syncope, is initiated by pooling of the venous blood in the lower extremities by prolonged standing or by abrupt assumption of an upright posture. This causes a sudden loss of preload and stroke volume. A sympathetic response is initiated, leading to tachycardia, vasoconstriction, and an increase in contractility. C-fiber mechanoreceptor activation causes afferent impulses to the medulla that, in turn, initiates a withdrawal of sympathetic activity and an activation of the parasympathetic system. This combination leads to venous and arterial vasodilatation, further lowering preload and blood pressure. The parasympathetic activity, carried by the vagus nerve to the heart, causes bradycardia, which can be severe. The result of these reactions is the loss of adequate cerebral blood flow, causing the loss of consciousness and postural tone. Occasionally, myoclonic movements can occur, but tonic-clonic seizures are rare. Once supine, venous return is restored, blood pressure and heart rate normalize, and consciousness returns. Within a few minutes, the patient feels well enough to stand and resume some activity. If the patient tries to stand too soon, a recurrent loss of consciousness is possible. Feeling tired is common, but true postictal symptoms are absent. In addition to gravity-dependent pooling of blood, injury, the fear of injury, pain, the sight of blood, anger, or disgust are known initiators of syncope. Hair combing is an unusual inciting event, and head turning, swallowing, micturition, or defecation are uncommon triggers in children but have been described in adults.
DIAGNOSIS
In children with syncope, the diagnosis is usually benign neurocardiogenic syncope.18,19 However, the differential diagnosis is large and there are many diseases, some life-threatening, that may present as a syncopal episode (Table 486-2).
A syncopal event often produces considerable anxiety for the patient, family, and perhaps the evaluating physician. Certainly, some patients with syncope live in an environment with significant psychological difficulties.22 This often leads to extensive evaluations that yield no pathology.23,24 A careful, complete history and physical along, with an electrocardiogram, is generally all that is needed to determine the diagnosis. The evaluation should be targeted at screening for more ominous etiologies such as abnormal cardiac function, dysrhythmia, neurologic disease, or psychiatric conditions. Specific information about the event from witnesses should be sought in addition to the patient’s account. Clues from the patient’s history that may indicate a more serious cause of syncope are listed in Table 486-3. Syncope with exercise warrants a thorough cardiovascular evaluation.
Table 486-2. Diseases That May Present as Syncope
The physical examination should confirm normal vital signs as well as evaluate orthostatic changes in heart rate and blood pressure. Body habitus should be assessed. The mental status should be age appropriate. Minor defensive injuries such as abrasions on the hands and arms may be present, but there is usually no serious injury. The cardiac examination should confirm the absence of increased precordial activity that may indicate valvular obstruction or hypertrophic cardiomyopathy, as well as the absence of gallops, murmurs, and abnormal peripheral pulses. The neurologic exam should focus on discovering focal deficits.
An electrocardiogram is recommended for any child presenting with syncope. In addition to confirming normal cardiac rhythm and age-appropriate heart rate, it is important to manually confirm a normal QT interval (see Chapter 493). The QRS complexes should be inspected for evidence of preexcitation (delta waves with shortened PR intervals and broad QRS complexes) suggestive of Wolff-Parkinson-White syndrome (see Chapter 485). Abnormal ST segments may indicate ischemia, pericarditis, or a channelopathy such as Brugada syndrome. Abnormally high QRS voltage could indicate chamber hypertrophy or enlargement. Conversely, low voltage may indicate myocarditis.
Table 486-3. History Findings Suggestive of Nonvasovagal Causes of Syncope
Other testing may be indicated based upon the history, examination, or electrocardiogram, but often serious pathology can be excluded by this evaluation. Without concerning findings on history or physical examination, echocardiography has not been shown to increase the diagnosis of a serious disorder.25 Tilt table testing has been used for diagnosis in patients with syncope but has poor reproducibility, sensitivity, and specificity. The American College of Cardiology and the Heart Rhythm Society no longer recommend tilt-testing for patients with presentations typical for neurocardiogenic syncope.26
TREATMENT OF NEUROCARDIOGENIC SYNCOPE
For atypical presentations, worrisome family histories, or abnormalities on physical examination or electrocardiography, referral for specialized evaluation is warranted. However, once more serious disease is excluded and if a diagnosis of neurocardiogenic syncope is established, therapy is designed to minimize episodes. Foremost is the education of the patient and family about the mechanism and avoidance of known triggers. The maintenance of circulating volume status through hydration is paramount.27 An active adolescent may need up to 4 L of fluid a day, depending on activities. Caffeine, because of its sympathomimetic and diuretic effects, should be avoided. If simple measures do not suffice, salt (250–1000 mg) can be added to the diet. Fludrocortisone has been beneficial in some patients,28 as have beta-blockers and α-agonists.29,30 If syncope involves severe bradycardia, pacemaker therapy has been employed with success.31
HYPERTENSION
Systemic hypertension is often thought of as a disease of adults, but in fact often has its antecedents in childhood or adolescence. Management includes 3 discrete steps: detection by proper measurement of blood pressure; correction of any structural, renal, or endocrine causes. Among cardiac causes, coarctation of the aorta should be considered. Despite the fact that this anomaly can be diagnosed readily without the need for laboratory testing or imaging, coarctation often goes undetected until adolescence or even adulthood.1 In most patients with coarctation, but not all, femoral pulses are diminished or totally absent. Whereas in normal subjects the supine systolic blood pressure in the legs is higher than that in the arms, pressures are reversed in the presence of coarctation. Arm pressures more than 10 mm Hg higher than leg pressures should raise suspicion for coarctation of the aorta.44 It is important to use systolic, not mean or diastolic pressures, for the diagnosis and follow-up of patients with coarctation. Normal blood pressure standards, diagnostic workup, and pharmacologic therapy of hypertension are discussed in Chapter 479.
PULMONARY HYPERTENSION
Pulmonary hypertension in children, as in adults, is extremely serious (see Chapter 492).33-35 It occurs in several situations in children and adolescents: Most common is pulmonary hypertension associated with structural congenital cardiac abnormalities, especially those with increased pulmonary blood flow. Pulmonary hypertension is also seen in pediatric patients with respiratory diseases, especially chronic lung disease of the premature and late stages of cystic fibrosis. Although less common in children than adults, pulmonary hypertension is also seen in systemic disorders, including the hemoglobinopathies, thromboembolic disease, and portal hypertension, and collagen vascular diseases, such as scleroderma and systemic lupus erythematosus. Pulmonary hypertension without an obvious underlying cardiac abnormality systemic disease is referred to as idiopathic pulmonary hypertension.
Pulmonary hypertension is defined as a mean pulmonary artery pressure of greater than 25 mmHg or greater than 30 mm Hg with exercise. Although this definition is useful for clinical trials, its limitations are that it often requires cardiac catheterization for an accurate diagnosis and that it may be too high for infants and young children in whom these values represent a much higher percentage of their systemic arterial pressure than in adults.
PULMONARY HYPERTENSION ASSOCIATED WITH CONGENITAL HEART DISEASE
Pulmonary hypertension is present in many congenital cardiac abnormalities, especially those with increased pulmonary blood flow, large communications between the ventricles or great arteries, and those with obstruction to pulmonary venous return. Usually, the elevated pulmonary artery pressure decreases if the underlying condition is repaired or palliated within the first 1 or 2 years of life.
It is important to distinguish pulmonary hypertension from pulmonary vascular obstructive disease. The former is simply elevation of pulmonary artery pressure due to increased flow and pulmonary arteriolar vasoconstriction. Pulmonary vascular obstructive disease is a late consequence of uncorrected cardiac abnormalities and is characterized by irreversible anatomic changes of the pulmonary arterial bed, including intimal sclerosis, occlusion of small vessels, abnormal extension of vascular smooth muscle into peripheral vessels, and reduction in the number of small arteries.36 Reversal of a previous left-to-right shunt (ie, Eisenmenger syndrome) is an ominous but late phenomenon. Pulmonary vascular obstructive disease is uncommon in the first year of life, and its incidence has decreased with earlier repair of many cardiac defects. It tends to develop earlier in patients with hypoxemia (transposition of the great arteries, truncus arteriosus), respiratory disease, and Down syndrome.
Pulmonary vascular disease in adolescents and adults with congenital heart disease is a multisystem disorder. Those affected typically have decreased exercise capacity, chronic cyanosis, erythrocytosis, and abnormal hemostasis.37Patients are at risk for both endocarditis and systemic infections, especially brain abscess. Survival is longer than in idiopathic pulmonary hypertension, with many patients living into the third or fourth decade.37,38
Table 486-4. Common Chromosomal Disorders and Associated Cardiac Defects
IDIOPATHIC PULMONARY HYPERTENSION
Idiopathic pulmonary hypertension is typically a disease of young adults, especially women, but it may occur in the second and even first decade of life.39,40 Symptoms are nonspecific and include fatigue, dyspnea, chest pain, and exercise intolerance. Syncope is a late and ominous occurrence. Physical findings may be subtle and include a right ventricular lift at the left sternal border and accentuation of the pulmonary component of the second heart sound. Late findings include murmurs of tricuspid or pulmonary insufficiency, hepatomegaly, jugular venous distention, and peripheral edema. Survival more than 5 years after diagnosis is rare.
Idiopathic pulmonary hypertension is a diagnosis of exclusion. Patients with suspected or confirmed pulmonary hypertension should undergo a comprehensive evaluation to attempt to establish a treatable cause. This includes tests of pulmonary, coagulation, hepatic, and thyroid function as well as assessment for connective tissue disease.35
MANAGEMENT OF THE CHILD WITH CONGENITAL HEART DISEASE BY THE PRIMARY CARE PHYSICIAN
IMMUNIZATIONS
In general, children and adolescents with cardiovascular disorders should receive all the usual childhood immunizations. Heart disease does not protect against pertussis or polio! In patients with marked hypoxemia and polycythemia, parents should be counseled to ensure adequate hydration in the event of postimmunization fever. Likewise, it is advisable to avoid immunizations in days immediately prior to scheduled diagnostic procedures or surgeries to avoid possible cancellations due to fever.
Respiratory infections may pose serious problems for children with congenital heart disorders, especially those with increased pulmonary blood flow. All patients over 6 months of age should receive influenza vaccine annually. Additionally, immunization against respiratory syncytial virus with palivizumab (Synagis) has been shown to reduce hospitalizations in infants with hemodynamically significant congenital heart disease.41 It should be administered in monthly doses during the respiratory syncytial virus season (November to April), similar to the schedule recommended for premature infants.
Patients with functional asplenia deserve special consideration. They should receive multivalent pneumococcal and meningococcal vaccines at 2 years of age. They should also receive daily antibiotic prophylaxis (amoxicillin) against encapsulated organisms (Tables 486-4 and 486-5).
ENDOCARDITIS PROPHYLAXIS
Recognizing the morbidity and mortality associated with infective endocarditis, the American Heart Association published a series of guidelines for its prevention, beginning in 1955.42 The guidelines have changed in response to newer antibiotics and increased understanding of organisms, mechanisms, and risks. Perhaps the most sweeping change in the guidelines is that presented in the 2007 revision42: After decades of recommending antibiotic prophylaxis prior to dental and surgical procedures in patients with even minor structural cardiac anomalies, such prophylaxis is now recommended only for patients in the highest risk categories, and, for dental procedures, only those involving manipulation of gingival tissue or the periapical region of teeth or perforation of oral mucosa (Table 486-6). Oral amoxicillin (2 g for adults, 50 mg/kg for children) is the recommended antibiotic for most patients. Parenteral ampicillin (2 g for adults, 50 mg/kg for children) is recommended for those who cannot take oral medication and cephalexin or clindamycin for those allergic to penicillin. Prophylaxis is no longer recommended for genitourinary or gastrointestinal tract procedures.
Table 486-5. Murmurs Associated with Common Congenital Cardiac Defects
Table 486-6. Cardiac Conditions for Which Antibiotic Prophylaxis for Dental Procedures Is Recommended
|
Prosthetic heart valve or prosthetic material used for valve repair |
|
Previous infective endocarditis |
|
Congenital heart diseases |
|
Unrepaired cyanotic congenital heart disease, including palliated cyanotic congenital heart disease |
|
Repaired congenital heart disease with surgery or catheter intervention using prosthetic material device during the first 6 months after the procedure |
|
Repaired congenital heart disease with residual defects adjacent to a prosthetic patch or device |
|
Cardiac transplant recipients with a cardiac valvulopathy |
These recommendations represent a change that may confuse and even frighten patients, families, and health care professionals who have been admonished to use antibiotics for even minor procedures in patients with trivial heart abnormalities. Among the reasons for the changes is the recognition that the risk of bacteremia is much greater from daily chewing and brushing than from the occasional dental procedure. Maintenance of good dental hygiene should be a priority for all children, but especially those with congenital heart disease.
POLYCYTHEMIA
Patients with cyanotic congenital heart disease develop increased hemoglobin concentration and hematocrit in response to hypoxemia. This is generally beneficial as it increases the oxygen-carrying capacity of the blood. However, in some patients, the rise in hematocrit is excessive and produces symptoms attributable to hyperviscosity. With the advent of corrective surgical procedures for most congenital cardiac anomalies, this problem is much less frequent than in the past. However, there remains a cohort of patients, primarily teenagers and adults, with palliated or inoperable conditions who have hypoxemia and severe polycythemia. Typical symptoms include fatigue, headache, light-headedness, and paresthesias. Cerebral vascular accidents and systemic thrombosis have also been attributed to hyperviscosity.
Reduction phlebotomy has been used to lower hematocrit (if there are symptoms), or at an arbitrary level of hematocrit (often 70%), or to reduce the risk of stroke. The latter indication has been challenged,43and in fact some studies have suggested that iron deficiency and microcytosis are the major causes of cerebral vascular accidents in cyanotic patients.44,45 One adverse effect of reduction phlebotomy is that many patients develop iron deficiency and microcytosis, and indeed many of the symptoms of hyperviscosity overlap with those of iron deficiency. Because exercise capacity is directly related to hematocrit in adults with cyanotic congenital heart disease,46 it seems prudent to perform phlebotomy judiciously if at all and to ensure iron sufficiency. A red cell mean corpuscular volume greater than the 90th percentile for age has been used as a surrogate for adequate iron stores.47 Alternatively, a ratio of hematocrit to hemoglobin of over 3:1 suggests iron deficiency. Blood removed should be replaced with an equal or greater volume of saline.
MANAGEMENT OF HYPERTENSION
Blood pressure monitoring and aggressive therapy of hypertension is especially important in patients with conditions that predispose them to aortic dilation and aortic dissection. These include the syndrome of bicuspid aortic valve with aortic aneurysm (with or without coarctation of the aorta48), Marfan syndrome, and Turner syndrome.49,50 Patients with Williams syndrome have a diffuse arteriopathy with thick, noncompliant arteries that typically cause hypertension.51 Finally, surgical repair does not cure the hypertension of many patients with coarctation of the aorta, especially if diagnosis has been delayed.52,53 A thorough evaluation for recurrent or residual coarctation should precede medical therapy.
POSTPERICARDIOTOMY SYNDROME
Postpericardiotomy syndrome is an inflammatory condition occurring days to weeks after cardiac surgery, especially with cardiopulmo-nary bypass (see Chapter 491). Primary care physicians should be alert to this condition in patients returning to their care after cardiac surgery. Management generally consists of anti-inflammatory drugs, but pericardiocentesis is required for large effusions or tamponade.
COGNITIVE FUNCTION
Abnormalities of cognitive function are common in patients with congenital heart disease and range from subtle learning disorders to profound developmental delay.54-56 Many patients with congenital heart disease have an obvious clinical syndrome such as Down or Williams syndromes. Additionally, there is evidence that many patients with congenital heart disease have central nervous system abnormalities, even without a recognized clinical syndrome.57Cardiac surgery with cardiopulmonary bypass or circulatory arrest may adversely affect cognitive function.58 The primary care physician must be aware of these risks and help the family obtain appropriate diagnostic testing and educational intervention.