1 Routine Cardiac Evaluation in Children

Initial evaluation of children with possible cardiac problems includes (1) history taking, (2) physical examination, (3) electrocardiographic (ECG) evaluation, and (4) chest x-ray (CXR). The weight of information gained from these techniques varies with the type and severity of the disease.

I. HISTORY TAKING

Prenatal, perinatal, postnatal, past, and family histories should be obtained.

A. GESTATIONAL AND PERINATAL HISTORY

1. Maternal infection: Rubella during the first trimester of pregnancy commonly results in PDA and PA stenosis (rubella syndrome, Table 1-1). Other viral infections early in pregnancy may be teratogenic. Viral infections (including human immunodeficiency virus) in late pregnancy may cause myocarditis.

2. Maternal medications: The following is a partial list of suspected teratogenic drugs (with reported CHDs). Amphetamines (VSD, PDA, ASD, and TGA), phenytoin (PS, AS, COA, and PDA), trimethadione (fetal trimethadione syndrome: TGA, VSD, TOF, HLHS; see Table 1-1), lithium (Ebstein anomaly), retinoic acid (conotruncal anomalies), valproic acid (various noncyanotic defects), and progesterone or estrogen (VSD, TOF, and TGA) are highly suspected teratogens. Warfarin may cause fetal warfarin syndrome (TOF, VSD, and other features such as ear abnormalities, cleft lip or palate, and hypoplastic vertebrae; see Table 1-1). Excessive maternal alcohol intake may cause fetal alcohol syndrome (in which VSD, PDA, ASD, and TOF are common; see Table 1-1). Cigarette smoking causes intrauterine growth retardation but not CHD.

3. Maternal conditions: Maternal diabetes increases the incidence of CHD (TGA, VSD, and PDA) and cardiomyopathy (see Table 1-1). Both maternal lupus erythematosus and collagen diseases have been associated with congenital heart block in the offspring. History of maternal CHD may increase the prevalence of CHD in the offspring to as much as 15%, compared with 1% in the general population (see Appendix A, Table A-2).

TABLE 1-1 MAJOR SYNDROMES ASSOCIATED WITH CARDIOVASCULAR ABNORMALITIES

B. POSTNATAL AND PRESENT HISTORY

1. Poor weight gain and delayed development may be caused by congestive heart failure (CHF), severe cyanosis, or general dysmorphic conditions. Weight is more affected than height.

2. Cyanosis, squatting, and cyanotic spells suggest TOF or other cyanotic CHD.

3. Tachycardia, tachypnea, and puffy eyelids are signs of CHF.

4. Frequent lower respiratory tract infections may be associated with large L-R shunt lesions.

5. Decreased exercise tolerance may be a sign of significant heart defects or ventricular dysfunction.

6. Heart murmur. The time of its first appearance is important. A heart murmur noted shortly after birth indicates a stenotic lesion (AS, PS). A heart murmur associated with large L-R shunt lesions (such as VSD or PDA) may be delayed. Appearance of a heart murmur in association with fever suggests an innocent murmur.

7. Chest pain. Ask if chest pain is exercise related or nonexertional; also ask about its duration, nature, and radiation. Nonexertional chest pain is unlikely to have cardiac causes. Cardiac causes of chest pain are usually associated with exertional pain and are very rare in children and adolescents. The three most common causes of nonexertional chest pain in children are costochondritis, trauma to chest wall or muscle strain, and respiratory diseases (see Child with Chest Pain in Chapter 6).

8. Palpitation may be caused by paroxysms of tachycardia, sinus tachycardia, single premature beats; rarely hyperthyroidism or mitral valve prolapse (MVP) (see Chapter 6).

9. Joint pain. Joints involved, presence of redness and swelling, history of trauma, duration and migratory or stationary nature of the pain, recent sore throat, rashes, family history of rheumatic fever, or the diagnosis of rheumatoid arthritis are important.

10. Neurologic symptoms. Stroke may result from embolization of thrombus from infective endocarditis, polycythemia, or uncorrected or partially corrected cyanotic CHD. Headache may be associated with polycythemia or, rarely, with hypertension. Choreic movement may result from rheumatic fever. Fainting or syncope may be due to vasovagal responses, arrhythmias, long QT syndrome, epilepsy, or other noncardiac conditions (see “Syncope” in Chapter 6).

11. Note medications, cardiac and noncardiac (name, dosage, timing, and duration).

12. Syndromes and diseases of other systems with associated cardiovascular abnormalities are summarized in Table 1-1.

C. FAMILY HISTORY

1. Certain hereditary diseases may be associated with varying frequency of cardiac anomalies (see Table 1-1).

2. CHD in the family. The incidence of CHD in the general population is about 1% (8 to 12 per 1000 live births). When one child is affected, the risk of recurrence in siblings is increased to about 3% (see Table A-1 in Appendix A). However, the risk of recurrence is related to the incidence of particular defects: Lesions with high prevalence (e.g., VSD) tend to have a high risk of recurrence, and those with low prevalence (e.g., tricuspid atresia, persistent truncus arteriosus) have a low risk of recurrence (see Appendix A, Table A-1). The probability of recurrence is substantially higher when the mother, rather than the father, is the affected parent (see Appendix A, Table A-2). Tables A-1 and A-2 can be used for counseling.

II. PHYSICAL EXAMINATION

A. INSPECTION

1. Assess general appearance: happy or cranky, nutritional state, respiratory status (tachypnea, dyspnea, or retraction may be signs of serious CHD), pallor (vasoconstriction from CHF or circulatory shock or severe anemia), and sweat on the forehead (seen in CHF).

2. Inspect for any known syndromes or conditions (see Table 1-1).

3. Malformations of other systems may be associated with varying frequency of CHD (Table 1-2).

4. Acanthosis nigricans (a dark pigmentation of skin crease on the neck) is often seen in obese children and those with type 2 diabetes and may signify the presence of hyperinsulinemia.

5. Precordial bulge, with or without actively visible cardiac activity, suggests chronic cardiac enlargement. Pectus excavatum may be a cause of a heart murmur. Pectus carinatum is usually not a result of cardiomegaly.

6. Cyanosis usually signals a serious CHD. A long-standing arterial desaturation (usually more than 6 months), even of a subclinical degree, results in clubbing of the fingers and toes.

TABLE 1-2 INCIDENCE OF ASSOCIATED CHDs IN PATIENTS WITH OTHER SYSTEM MALFORMATIONS

ORGAN SYSTEM AND MALFORMATION	FREQUENCY (%)	SPECIFIC CARDIAC DEFECT
Central Nervous System
Hydrocephalus	6	VSD, ECD, TOF
Dandy-Walker syndrome	3	VSD
Agenesis of corpus callosum	15	No specific defect
Meckel-Gruber syndrome	14	No specific defect
Thoracic Cavity
TE fistula, esophageal atresia	21	VSD, ASD, TOF
Diaphragmatic hernia	11	No specific defect
Gastrointestinal System
Duodenal atresia	17	No specific defect
Jejunal atresia	5	No specific defect
Anorectal anomalies	22	No specific defect
Imperforate anus	12	TOF, VSD
Ventral Wall
Omphalocele	21	No specific defect
Gastroschisis	3	No specific defect
Genitourinary System
Renal agenesis
Bilateral	43	No specific defect
Unilateral	17	No specific defect
Horseshoe kidney	39	No specific defect
Renal dysplasia	5	No specific defect

ECD, endocardial cushion defect; TE, tracheoesophageal. Other abbreviations are listed on pp. xi-xii.

Adapted from Copel JA, Kleinman CS: Congenital heart disease and extracardiac anomalies: association and indications for fetal echocardiography, Am J Obstet Gynecol 154:1121–1132, 1986.

B. PALPATION

1. Precordium

a. A hyperactive precordium is characteristic of heart diseases with high volume overload, such as L-R shunt lesions or severe valvular regurgitation.

b. A thrill is often of real diagnostic value. The location of the thrill suggests certain cardiac anomalies: upper left sternal border (ULSB), PS; upper right sternal border (URSB), AS; lower left sternal border (LLSB), VSD; suprasternal notch, AS, occasionally PS, PDA, or COA; over the carotid arteries, AS or COA.

2. Peripheral pulses

a. Check the peripheral pulse for the rate, irregularities (arrhythmias), and volume (bounding, full, or thready).

b. Strong arm pulses and weak leg pulses suggest COA.

c. The right brachial artery pulse stronger than the left brachial artery pulse may suggest COA or supravalvular AS.

d. Bounding pulses are found in aortic runoff lesions (e.g., PDA, AR, large systemic AV fistula).

e. Weak and thready pulses are found in CHF and circulatory shock.

C. BLOOD PRESSURE

Every child should have blood pressure (BP) measurement as part of the physical examination whenever possible. To determine if the obtained BP level is normal or abnormal, BP readings are compared with reliable BP standards. Unfortunately, there have been problems and confusion regarding the correct method of measuring BP and the reliable normative BP values for children. Arm length–based BP cuff selection methods recommended by two NIH Task Forces (1977 and 1987) are scientifically unsound, and they have contributed to the lack of reliable normative BP standards for decades. Although the Working Group of the National High Blood Pressure Education Program (NHBPEP) has recently corrected the BP cuff selection method, its normative BP data are scientifically and logically unsound (see the following).

1. The following are currently recommended BP measurement techniques.

a. The width of the BP cuff should be 40% to 50% of the circumference of the arm (or leg) with the cuff long enough to completely or nearly completely encircle the extremity.

b. The NHBPEP recommends Korotkoff phase 5 (K5) as the diastolic pressure, but this is debatable. Earlier studies indicate that K4 agrees better with true diastolic pressure for children ≤12 years.

c. The average of two or more readings should be obtained.

d. The child should be in a sitting position with the arm at the heart level.

2. The normative BP standards recommended by the Working Group are not evidence based and are impractical for use by busy practitioners.

a. The Working Group’s BP data have been derived from the methodology that is discordant with the Working Group’s own recommendations; that is, the BP values are derived from currently invalid methods of NIH Task Force-1987 (with BP cuff width selected by the arm length). In addition, they are single measurements rather than averages of multiple readings, as currently recommended.

b. Rationale for checking BP values according to age and height percentile is statistically and logically unsound. Partial correlation analysis in the San Antonio Children’s Blood Pressure Study (SACBPS) shows that when auscultatory (as well as oscillometric) BP levels were adjusted for age and weight, the correlation coefficient of systolic BP with height was very small (r ≡ 0.070), whereas when adjusted for age and height, the correlation of systolic pressure with weight remained high (r ≡ 0.318). Thus, there is no rationale to use both age and height percentile to express children’s BP standards. These findings indicate that the contribution of height to BP levels is negligible. The apparent contribution of height to BP levels may reflect its close correlation with weight (r ≡ 0.86). Although weight is a very important contributor to BP, weight cannot be used as a second variable because this would interfere with detection of high BP in obese children. Therefore, we recommend children’s BP values be expressed as a function of age only as has been done earlier by NIH Task Forces.

c. Recommendation of requiring additional computational steps to classify the level of a child’s BP is unwise because BP levels obtained in a doctor’s office are highly variable and not reproducible, unlike weight or height measurement.

3. Normative percentile curves from the San Antonio study are the only standards obtained according to the currently recommended methodology, including that of the NHBPEP (Figs. 1-1 and 1-2). BP values are the averages of three readings. In using these percentile curves, one should consider the patient’s weight status before making the diagnosis of hypertension (BP levels ≥ 90th percentile). If the BP level is higher than the 90th percentile for the age and gender on three occasions, hypertension can be diagnosed, but the extent this abnormality is associated with weight should be considered before any presumption of organic disease is made. Percentile values of auscultatory systolic and diastolic pressures for children 5 to 17 years old are presented in Appendix B (Tables B-3 and B-4). Although BP standards recommended by the NHBPEP are unscientific, they are presented in Tables B-1 and B-2 for the sake of completeness.

4. Oscillometric blood pressure values. It should be noted that BP readings by the auscultatory method and the currently popular oscillometric devices are not interchangeable. In the San Antonio Children’s Blood Pressure Study, BP measurements were obtained using both the auscultatory and Dinamap (model 8100) methods. BP levels obtained by the Dinamap were on average 10 mm Hg higher than levels obtained by the auscultatory method for the systolic pressure and 5 mm Hg higher for the diastolic pressure. Therefore, one should use different normative BP standards when BP is obtained by the Dinamap method. Dinamap-specific BP standards for children 5 through 17 years of age are presented in Tables B-5 and B-6. Normative BP standards by Dinamap for neonates and children up to 5 years of age are presented in Table 1-3.

5. The following are additional comments regarding BP measurements in children and adolescents.

a. How to interpret arm and leg BP values. Four-extremity BP measurements are often obtained in neonates and children to rule out COA. Even with a considerably wider cuff used for the thigh, the Dinamap systolic pressure in the thigh or calf is about 5 to 10 mm Hg higher than that in the arm. This reflects in part the peripheral amplification of systolic pressure (see the following). If the systolic pressure is lower in the leg, COA may be present. The peripheral amplification is not seen in the neonate, probably due to the presence of normal isthmic narrowing in this age group.

b. The concept of peripheral amplification of systolic pressure. Many physicians incorrectly think that peripherally measured BP, such as that measured in the arm, is the same as the central aortic pressure. The peripheral systolic pressure, obtained by either direct or indirect method, is not always the same as the central aortic pressure. In fact, arm systolic pressures are in general higher than central aortic pressures and are much higher in certain situations. This phenomenon is called peripheral amplification of systolic pressure (Fig. 1-3). The systolic amplification increases as the site of BP measurement moves distally. The following summarizes key points of the phenomenon.

(1) The amplification is limited to the systolic pressure (not in the diastolic pressure).

(2) The systolic amplification is greater in children (with more reactive arteries) than in older adults who may have degenerative arterial disease.

(3) Pedal artery systolic pressures are higher than the radial artery pressures.

(4) The amplification is more marked in vasoconstricted states.

(a) Patients in impending circulatory shock (with a high level of circulating catecholamines) may show normal peripheral artery systolic pressure when the central aortic pressure is abnormally low. Monitoring the mean arterial and diastolic pressures should be more useful in this situation.

(b) Subjects receiving catecholamine infusion or other vasoconstrictors may show much higher peripheral systplic pressure than central aortic pressure.

(c) A child in congestive heart failure (in which peripheral vasoconstriction exists) may exhibit an exaggerated systolic amplification.

(d) Arm systolic pressure in subjects running on treadmill can be markedly higher than the central aortic pressure.

FIG. 1-1 Age-specific percentile curves of auscultatory systolic and diastolic (K5) pressures in boys 5 to 17 years of age. BP values are the averages of three readings. The width of the BP cuff was 40% to 50% of the circumference of the arm. The percentile values for the graph are shown in Appendix B,.

(From Park MK, Menard SW, Yuan C: Comparison of blood pressure in children from three ethnic groups, Am J Cardiol 87:1305–1308, 2001.)

FIG. 1-2 Age-specific percentile curves of auscultatory systolic and diastolic (K5) pressures in girls 5 to 17 years of age. BP values are the averages of three readings. The width of the BP cuff was 40% to 50% of the circumference of the arm. The percentile values for the graph are shown in Appendix B, Table B-4.

(From Park MK, Menard SW, Yuan C: Comparison of blood pressure in children from three ethnic groups, Am J Cardiol 87:1305–1308, 2001.)

TABLE 1-3 NORMATIVE BLOOD PRESSURE LEVELS [SYSTOLIC/DIASTOLIC (MEAN)] (IN MM HG) BY DINAMAP MONITOR (MODEL 1846 SX) IN CHILDREN UP TO AGE 5 YEARS

FIG. 1-3 Schematic drawing of pulse wave changes seen at different levels of the systemic arteries.

(From Park MK: Pediatric cardiology for practitioners, ed 5, Philadelphia, 2008, Mosby.)

D. AUSCULTATION

Systematic attention should be given to heart rate and regularity; intensity and quality of the heart sounds, especially the second heart sound; systolic and diastolic sounds (ejection click, midsystolic click, opening snap); and heart murmurs.

1. Heart sounds

a. The first heart sound (S1) is associated with closure of the mitral and tricuspid valves and is best heard at the apex or LLSB. Splitting of the S1 is uncommon in normal children. Wide splitting of the S1 may be found in right bundle branch block (RBBB) or Ebstein anomaly.

b. The second heart sound (S2), which is produced by the closure of the aortic and pulmonary valves, is evaluated in the ULSB (or the pulmonary area) in terms of the degree of splitting and the relative intensity of the P2 (the pulmonary closure sound) in relation to the intensity of the A2 (the aortic closure sound). Although best heard with a diaphragm, both components are readily audible with the bell as well.

(1) The degree of splitting of the S2 normally varies with respiration, increasing with inspiration and decreasing or becoming single with expiration (Fig. 1-4).

(2) Abnormal S2 may take the form of wide splitting, narrow splitting, single S2, abnormal intensity of the P2, or, rarely, paradoxical splitting of the S2 (see Box 1-1 for summary of abnormal S2).

c. The third heart sound (S3) is best heard at the apex or LLSB (Fig. 1-5). It is commonly heard in normal children, young adults, and patients with dilated ventricles and decreased compliance of the ventricles (e.g., large-shunt VSD, CHF).

d. The fourth heart sound (S4) at the apex, which is always pathologic (Fig. 1-5), is seen in conditions with decreased ventricular compliance or CHF.

e. Gallop rhythm generally implies pathology and results from the combination of a loud S3 or S4 and tachycardia. It is common in CHF.

2. Systolic and diastolic sounds

a. An ejection click sounds like splitting of the S1 but is best heard at the base rather than at the LLSB (Fig. 1-5). The ejection click is associated with stenosis of the semilunar valves (e.g., PS at 2LICS and to 3LICS, AS at 2RICS or apex) and enlarged great arteries (e.g., systemic hypertension, pulmonary hypertension, and TOF).

b. A midsystolic click with or without a late systolic murmur is heard near the apex in patients with MVP (Fig. 1-5).

c. Diastolic opening snap is audible at the apex or LLSB in mitral stenosis (MS) (Fig. 1-5).

3. Heart murmur. Each heart murmur should be analyzed in terms of intensity, timing (systolic or diastolic), location, transmission, and quality (e.g., musical, vibratory, blowing).

a. Intensity of the murmur is customarily graded from 1 to 6.

(1) Grade 1, barely audible

(2) Grade 2, soft but easily audible

(3) Grade 3, moderately loud but not accompanied by a thrill

(4) Grade 4, louder and associated with a thrill

(5) Grade 5, audible with the stethoscope barely on the chest

(6) Grade 6, audible with the stethoscope off the chest

b. Classification of heart murmurs. Heart murmurs are classified as systolic, diastolic, or continuous.

c. Systolic murmurs

(1) A systolic murmur occurs between S1 and S2. Systolic murmur was initially classified by Aubrey Leatham in 1958 into two types, ejection or regurgitant, depending on the timing of the onset, not the termination, of the murmur in relation to the S1. Recently, Joseph Perloff proposed a new classification into four types according to the time of onset and termination: midsystolic (ejection), holosystolic, early systolic, and late systolic.

(a) Ejection systolic murmur (also called stenotic, diamond shaped, or Perloff’s midsystolic) has an interval between S1 and the onset of the murmur and is crescendo-decrescendo. The murmur may be short or long (Fig. 1-6, A). These murmurs are caused by the flow of blood through stenotic or deformed semilunar valves or increased flow through normal semilunar valves and are therefore found at the base or over the midprecordium. These murmurs may be pathologic or innocent.

(b) Regurgitant systolic murmur begins with the S1 (no gap between the S1 and the onset of the murmur) and usually lasts throughout systole (pansystolic or holosystolic) but may be decrescendo ending in middle or early systole (Fig. 1-6, B). Perloff’s holosystolic and early systolic murmurs are regurgitant murmurs. These murmurs are always pathologic and are associated with only three conditions: VSD, MR, and TR.

(2) Location. In addition to the type of murmur (ejection vs. regurgitant), the location of maximal intensity of the murmur is of great importance in determining the origin (Tables 1-4 through 1-7 and Fig. 1-7).

(3) Transmission. A systolic ejection murmur at the base that transmits well to the neck is likely to be aortic, and one that transmits well to the sides of the chest and the back is likely to arise in the pulmonary valve or pulmonary artery.

(4) Quality. Ejection systolic murmurs of AS or PS have a rough, grating quality. A common innocent murmur in children (Still murmur) has a characteristic vibratory or humming quality.

(5) Differential diagnosis by location. Figure 1-7 illustrates systolic murmurs that are audible at the various locations. Tables 1-4 through 1-7 summarize other clinical findings (e.g., physical examination, CXR, ECG) that may aid diagnosis according to the location of a systolic murmur.

d. Diastolic murmurs. Diastolic murmurs occur between S2 and S1. Three types exist.

(1) Early diastolic (protodiastolic) decrescendo murmurs are caused by AR or PR (Fig. 1-8). AR murmurs are high pitched, are best heard at the 3LICS, and radiate to the apex. PR murmurs are usually medium pitched but may be high if pulmonary hypertension is present, best heard at the 2LICS, and they radiate along the left sternal border.

(2) Middiastolic murmurs are low pitched, starting with a loud S3 (Fig. 1-8). Best heard with the bell of the stethoscope, these murmurs are caused by anatomic or relative stenosis of the mitral or tricuspid valve. MS murmurs are best heard at the apex (apical rumble), and TS murmurs are heard along the LLSB.