Heart Murmurs in Pediatric Patients: When Do You Refer? MICHAEL E. MCCONNELL, M.D., SAMUEL B. ADKINS III, M.D., and DAVID W. HAXNON, M.D. East Carolina University School of Medicine, Greenville, North Carolina

Many normal children have heart murmurs, but most children do not have heart dis- ease. An appropriate history and a properly conducted physical examination can iden- O A patient infor- tify children at increased risk for significant heart disease. Pathologic causes of systolic mation handout on murmurs include atrial and ventricular septal defects, pulmonary or aortic outflow tract heart murmurs in chil- abnormalities, and . An is often confused dren, written by the with a functional murmur, but the conditions can usually be differentiated based on authors of this article, specific physical findings. Characteristics of pathologic murmurs include a sound level is provided on page 565. of grade 3 or louder, a diastoMc murmur or an increase in intensity when the patient is standing. Most children with any of these findings should be referred to a pediatric car- diologist. (Am Fam Physician 1999;60:558-65.)

rimary care physicians frequently formed in adult cardiology practices were encounter children with heart unnecessary in 30 percent of patients, were of murmurs.' Most of these young inadequate quality in 32 percent of patients patients do not have heart disease. and resulted in an erroneous impression of One set of investigators^ found the nature or presence of pathologic disease in thaPt physicians were generally accurate in 32 percent of patients. determining whether a murmur was benign or This article reviews the individual steps in the pathologic. Nonetheless, 61 percent of the mur- cardiac physical examination and the possible murs referred for subspecialist evaluation were innocent or pathologic findings. The focus is on found to be functional, or innocent, murmurs. helping physicians become even more confident The investigators hypothesized that increased about their ability to diagnose innocent mur- education of health care providers and parents murs and to decide which patients might bene- might be helpful in alleviating unnecessary fit from pediatric cardiology referral. anxiety and reducing the number of patients with innocent murmurs who are referred for General Approach further evaluation.- Busy clinicians need an approach that Echocardiography is not always needed to allows them to appropriately identify and refer diagnose pediatric murmurs. One study-* patients with pathologic murmurs to a pedi- showed that direct referral for echocardiogra- atric cardiologist. This approach should also phy was an expensive way to evaluate children help them know when they can confidently re- with heart murmurs. Pediatric cardiology assure the parents of a child with a functional consultation was significantiy less costly in murmur that referral is unnecessary. that many innocent murmurs were diagnosed In a busy office practice, time constraints without echocardiography. A recent stud/* make it difficult to perform a complete cardiac found that pediatric echocardiograms per- physical examination on every patient. How- ever, this examination must be performed on any child who has a or histori- cal features that indicate the presence of heart .ardidc pathology should be suspected In infants with a disease or abnormal cardiac function. Fea- history of poor feeding, failure to thrive, unexplained tures of concern in infants include feeding respiratory symptoms or . intolerance, failure to thrive, respiratory symptoms or cyanosis. In older children, chest

558 AMF.RICAN FAMILY PHYSICIAN VOLUME 60, NUMBER 2 / AUGUST 1999 pain (especially with exercise), syncope, exer- cise intolerance or a family history of sudden Tihe sounds of a venous hum should disappear when the child death in young people should prompt a com- is in the supine position, when light pressure is applied over plete examination. the child's jugular vein or when the child's head is turned. The examination is conducted in a quiet room. An infant may lie quietly on the exam- ination table. However, it can be challenging to keep a one- to two-year-old child quiet separate evaluation of each heart sound and enough for a good examination to be per- each phase of the cardiac cycle.' formed. Having the child sit in the lap of a parent or other caregiver may be helpful. FIRST HEART SOUND begins with listening for the Precordial Palpation first heart sound (S,) at the lower left border The begins with palpa- of the sternum. The S, is caused by closure of tion to assess precordial activity and femoral the mitral and tricuspid valves and is normally . Increased precordial activity is com- a single sound. An inaudible S, indicates that monly felt in patients with increased right or some sound is obscuring the closure sound of left ventricular stroke volume. Increased pre- these valves. The for cordial activity occurs in patients with an murmurs that obscure S, includes ventricular atrial septal defect, a moderate or large ven- septal defects, some murmurs caused by atri- tricular septal defect or significant patent duc- oventricular valve regurgitation, patent ductus tus arteriosus. This increased activity should arteriosus and, occasionally, severe pulmonary raise the possibility that the auscultatory find- valve stenosis in a young child. These S.-coin- ings may be pathologic. Other explanations cident murmurs are also known as "holosys- for increased precordial activity include tolic" murmurs. patient anxiety, anemia and hyperthyroidism. Once both brachial pulses have been pal- CLICKS pated, the right brachial should then be If SI is audible but appears to have two com- palpated simultaneously with the femoral ponents at some spots in the precordium, the pulse. If the timing and intensity of the two patient has either a click or an asynchronous pulses are equal and biood pressure in the closure of the mitral and tricuspid valves. right arm is normal, coarctation of the aorta is Clicks may originate from any valve in the unlikely. heart. Depending on their origin, clicks have Precordial palpation is also necessary to feel different identifying characteristics. "thrills," which are the palpable consequence of Ejection clicks originating from the pul- blood flowing rapidly from high pressure to monic valve begin shortly after the atrioven- lower pressure. Some ventricular septal defects tricular valves close, vary with respiration result in thrills at the lower left sternal border. and are best heard at the upper to middle Moderate to severe pulmonary valve stenosis area of the left sternal border. Aortic valve may cause a thrill at the upper left sternal bor- ejection clicks begin shortly after S, and are der. A thrill resulting from is fre- best heard at the apex. They do not vary with quently palpable in the suprasternal notch. respiration. Systolic clicks originating from the mitral Auscultation of First valve are best heard at the apical area when the and Second patient is standing. Occasionally, the tissue Precordial palpation is followed by auscul- closing a ventricular septal defect can pop or tation. This part of the examination entails click early in systole (Figure I).

AUGUST 1999 / VOLUME 60, NUMBER 2 AMERICAN FAMILY PHYSICIAN 559 sure of the pulmonary valve. The splitting of In patients with an atrial septa! defect, the features of S, occurs because inspiration brings more increased precordial activity, a widely split heart sound, a sys- blood into the right ventricle. Right ventricu- tolic murmur and a diastolic rumble are often present. lar ejection is prolonged, and the pulmonary valve closes later. An awareness of this phe- nomenon is helpful in understanding the physical examination features of the patient SECOND HEART SOUND with an atrial septal defect. A loud, single S^ After auscultation for clicks throughout indicates either pulmonary hypertension or the four listening areas, the next step is to congenital heart disease involving one of the return to the upper left sternal border and semilunar valves. listen to the second heart sound (S;)- This sound is caused by closure of the aortic and Murmurs pulmonic valves. Systolic murmurs have only a few possible The S2 should split into two components causes: blood flow across an outflow tract when the patient inspires. The first compo- (pulmonary or aortic), a ventricular septal nent, aortic second sound (A,), is closure of defect; atrioventricular valve regurgitation, or the aortic valve. The second component, pul- persistent patency of the arterial duct {ductus monic second sound (P;), is caused by clo- arteriosus). Systolic murmurs can also be functional (benign).

GRADES Systolic murmurs are graded on a six-point scale. A grade 1 murmur is barely audible, a grade 2 murmur is louder and a grade 3 mur- mur is loud but not accompanied by a thrill. A grade 4 murmur is loud and associated with a palpable thrill. A grade 5 murmur is associ- ated with a thrill, and the murmur can be heard with the partially off the chest. Finally, the grade 6 murmur is audible without a stethoscope. All murmurs louder than grade 3 are pathologic.

TrMING Systolic murmurs may be timed as early, middle or late systolic. They can also be timed as holosystolic.

VENOUS HUMS Many children with functional murmurs have venous hums. These sounds are caused by the flow of venous blood from the head and neck into the thorax. They are heard con- FIGURE 1. Listening areas for clicks: upper right sternal border (URSB) for aortic valve clicks; upper left sternal border (ULSB) for pulmonary valve tinuously when the child is sitting. The sounds clicks; lower left sternal border (LLSB), or the tricuspid area, for ventricu- should disappear when light pressure is lar septal defects; apex for aortic or mitral valve clicks. applied over the jugular vein, when the child's

560 AMERICAN FAMILY PHYSICIAN Voi-UMK 60, NUMBER 2 / AUGUST 1999 Pediatric Heart Murmurs

head is turned or when the child is lying supine. Venous hums are common and are Functional Murmur not pathologic. Patients with venous hums do not require pediatric cardiology referral. All other diastolic murmurs are pathologic and therefore warrant referral.

DESCRIF»TION OF CHARACTER

The character, or tone, of a murmur may Exhalation Inspiration aid in the diagnosis. Words such as "harsh," "whooping," "honking," "blowing," "musical" Ventricular Septal Defect Atrial Septal Defect and "vibratory" may be useful, albeit some- what subjective, in describing murmurs. A "harsh" murmur is consistent with high- velocity blood flow from a higher pressure to a lower pressure. "Harsh" is often appropriate for describing the murmur in patients with t \ significant semilunar valve stenosis or a ven- S, A, P, tricular septal defect. Inspiration Inspiration and exhalation "Whooping" or "blowing" murmurs at the apex occur with mitral valve regurgitation. The FIGURE 2. Graphic representation of common pediatric murmurs. The term "flow murmur" is often used to describe diamond-shaped murmurs are crescendo/decrescendo. The murmur of a crescendo/decrescendo murmur that is a ventricular septal defect obscures the closure sound of the mitral and tricuspid valves and is termed "holosystolic." (S, = first heart sound; P2 heard in patients with a functional murmur = pulmonic second sound; A; = aortic second sound) (Figure 2). However, similar systolic ejection murmurs may be heard in patients with atrial septal defect, mild semilunar valve stenosis, POSITION CHANGES IN THE DIFFERENTIATION subaortic obstruction, coarctation of the aorta OF MURMURS or some very large ventricular septal defects. Position changes are very helpful in differ- Many functional or innocent murmurs are entiating functional and pathologic murmurs. "vibratory" or "musical" in quality. Still's mur- The vibratory functional murmur heard in a mur is the innocent murmur most frequently young child (Still's murmur) decreases in encountered in children. This murmur is usu- intensity when the patient stands. ally vibratory or musical.^

LOCATION OF HIGHEST INTENSITY TABLE 1 The location of the highest intensity of a Listening Areas for Common Pediatric Heart Murmurs murmur is also important (Table 1). A mur- mur caused by aortic stenosis is often best Area Murmur heard at the upper sternal border, usually on the right side. A murmur resulting from pul- Upper right sternal border Aortic stenosis, venous hum monary stenosis is heard best at the upper left Upper left sternal border Pulmonary stenosis, pulmonary flow murmurs, atrial septal defect, patent ductus arteriosus sternal border. A murmur caused by a ventric- Lower left sternal border Still's murmur, ventricular septal defect, tricuspid ular septal defect or tricuspid valve insuffi- valve regurgitation, hypertrophic ciency is heard at the lower left sternal border. cardiomyopathy, subaortic stenosis A murmur resulting from mitral valve regur- Apex Mitral valve regurgitation gitation is best heard at the apex.

AUGUST 1999 / VOI.UMF. 60, NUMBKR 2 AMERICAN FAMILY PHYSICIAN 561 TABLE 2 Physical Findings in Functional (Innocent) Heart Murmur and Atrial Septal Defect

Physical finding Innocent murmur Atrial septal defect

Precordial activity Normal Increased First heart sound (S,) Normal Normal Second heart sound (S^) Splits and moves with Widely split and fixed (i.e., does not move respiration with inspiration) Systolic murmur (supine) Crescendo/decrescendo C f escen do/decrescendo Possibly vibratory at lower "Flow" at upper left sternal border left sternal border Systolic murmur (standing) Decreases in intensity Does not change Diastolic murmur Venous hum Inflow "rumble" across tricuspid valve area

Most pathologic murmurs do not change mur. Overall, hypertrophic cardiomyopathy is significantly with standing. An important rare; however, it is one of the leading causes of exception is the murmur of hypertrophic car- sudden death in athletes.'' diomyopathy, a potentially life threatening condition. This murmur increases in intensity AtrJal Septal Defect when the patient stands. In the upright posi- Perhaps the best way to decide whether a tion, venous return to the heart is reduced, patient needs to be referred to a pediatric car- decreasing the left ventricular end diastolic diologist is to know confidently the clinical volume. As left ventricular size decreases, the findings of the atrial septal defect. The abnor- left ventricular outflow tract narrows, and the mal findings in patients with atrial septal systolic outflow obstruction increases. This defects are often quite subtle and thus are eas- narrowing increases the intensity of the mur- ily confused with the physical findings in patients with functional or innocent mur- murs (Table 2). Loud murmurs from ventric- ular septal defects or significant aortic or pul- The Authors monic stenosis are not subtle and are not often confused with innocent murmurs. MICHAEL E. MCCONNELL, M.D,, i5 associate professor of pediatrics at East Carolina University School of Medicine, Greenville, N.C, Dr. McConnell received his medical The first step in the examination is palpa- degree from the University of Alabama 5chool of Medicine, Birmingham. He com- tion for the precordial activity at the left ster- pleted a pediatric residency at Children's Hospital, Birmingham, Ala., and a fellowship nal border, feeling for increased activity that in pediatric cardiology at Children's Hospital Medical Center. Cincinnati. may be present from right ventricular enlarge- SAMUEL B, ADKINS III, M.D., is assistant residency director and director of primary care ment. The examination is performed with the sports medicine for the family practice residency program at East Carolina University School of Medicine. Dr. Adkins graduated from the University of Pittsburgh School of patient in a supine position. Medicine and completed a residency in family practice at St. Margaret Memorial Hos- Auscultation at the lower left sternal border pital, Pittsburgh. should reveal a normal, singie and easily audi- DAVID W. HANNON, M.D., is associate professor of pediatrics at East Carolina Uni- ble S|. Listening at the upper left sterna! bor- versity School of Medicine. Dr. Hannon received his medical degree from the Univer- der for Sj should reveal variable splitting with sity of South Florida College of Medicine, Tampa, and completed a pediatric residency and a cardiology fellowship at Children's Hospital Medical Center, Cincinnati. respiration. A widely that does not change with respiration indicates either com- Address correspondence to Michael E. McConnell, M.D., Division of Pediatric Cardiol- plete right bundle branch block or an atrial ogy, Brody Medical Sciences Building, East Carolina University School of Medicine, Greenville, NC 27858-4354. Reprints are not available from the authors. septal defect.

562 AMERICAN FAMILY PHYSICIAN VOLUME 60, NUMBER 2 / AUGUST 1999 Pediatric Heart Murmurs

Because of the increased volume of blood and no clicks are heard, the differential diag- in the right ventricle in the patient with an nosis of a grade 1 to grade 2 systolic murmur atrial septai defect, the S, always sounds as if is frequently a choice between an atrial septal the patient has taken a deep breath. This defect and a functional murmur. means that the volume of blood in the right In young children, it can be difficult to con- ventricle Is increased and it takes longer for fidently distinguish the respiratory variation of the ventricle to eject its contents, thus leading S. splitting in the patient with a normal mur- to a fixed, widely split S2. mur ft-om the fixed S2 splitting in the patient Murmurs heard in patients with atrial sep- with an atrial septal defect. Because the patient tal defects are often of low pitch and inten- with an asymptomatic atrial septal defea will sity. However, the intensity of the murmur is not develop pulmonary hypertension or other not a reliable basis for the diagnosis. The sys- permanent sequelae early in life, careful yearly tolic murmur is caused by an increased vol- follow-up examination by the primary care ume of blood coursing across the right ven- physician can be recommended. By the time a tricular outflow tract. If the murmur is child reaches preschool age, the normal or audible, it can be heard at the upper left ster- abnormal splitting of the S^ usually becomes nal border. clear (Table 3). Patients with atrial septal defects may also have a diastolic murmur. In this situation, Follow-up or Referral increased diastolic blood flow across the tri- A patient who has a pathologic cardiac ex- cuspid valve may cause a soft, often barely amination or who has cardiac symptoms and audible low-frequency "diastolic rumble." questionable findings on the cardiac examina- This sound is heard best with the bell of the tion should be referred to a pediatric cardiol- stethoscope placed at the lower left sternal ogist. A child with a malformation syndrome border. Pushing down with the bell causes the associated with congenital heart disease skin beneath the stethoscope to act as a dia- should also be referred for additional evalua- phragm. Consequently, only the high-fre- tion. Conversely, an asymptomatic patient quency sounds are heard. Releasing the ten- whose physical findings on a conscientiously sion on the bell allows the low-frequency performed cardiac examination indicate a low rumbling sound to become audible at the probability of cardiac pathology should be lower left sternal border. After the supine examination, the examina- tion should be repeated with the patient standing. If the patient has an atrial septal TABLE 3 defect, the features of increased precordial Features That Increase the activity, a widely split Sj, a systolic murmur at Likelihood of Cardiac Pathology the upper left sternal border and a diastolic rumble should still be present when the Symptoms such as patient is standing. If the patient has an inno- Family history of Marfan syndrome or sudden cent or ftinctional murmur, the precordial death in young family members activity should be normal, the S, should split Malformation syndrome (e.g., Down syndrome) and move with respiration, the systolic mur- Increased precordial activity Decreased femoral puises mur should decrease in intensity and no dias- Abnormai second heart sound tolic murmur should be present in the tricus- Ciicks pid valve area. Loud or harsh murmur If no symptoms are present, the S, is nor- Increased intensity of murmur when patient stands mal, the S2 splits and is of normal intensity,

AUGUST 1999 / VOLUME 60, NUMBER 2 AMERICAN FAMILY PHYSICL\N 563 Pediatric Heart Murmurs

followed by the primary care physician. Refer- and at the same time increase their ability to ral is indicated if possibly pathologic findings confidently reassure families when referral is emerge on serial examinations.' unnecessary.

Final Comment REFERENCES Many normal children have heart mur- Rosenthal A. How to distinguish between innocent murs, but all of these children do not require and pathoiogic murmurs in chiidhood. Pediatr Clin referral to a pediatric cardiologist. Atrial septal North Am 1984:31:1229-40. defect is the pathologic diagnosis that is fre- McCrindle BW, Shaffer KM, Kan JS, Zahka

564 AMERICAN FAMILY PHYSICIAN VOLUME 60, NUMBER 2 / AUGUST 1999