Heart Murmurs, Congenital Heart Disease, and Acquired Heart Disease

Amy D. DiVasta

Mark E. Alexander

Cardiac murmurs occur in at least 50% of all normal children and often persist into adolescence and young adulthood. Murmurs are the most frequent reason for referral to a cardiologist.¹ The vast majority are considered to be “innocent” or “physiologic” in origin. In most patients with a cardiac murmur, a careful history and physical examination establish a diagnosis and/or guide further referral and evaluation.

HISTORY

Murmurs first heard in childhood or adolescence are more likely to be innocent murmurs. Complaints of fatigue, decreased exercise tolerance, exertional chest pain, or palpitations are suggestive of pathologic heart disease.² Any adolescent or young adult with syncope or near-syncope during exercise merits a cardiac evaluation. A thorough family history should also be obtained, including a history of sudden death or a structural cardiac abnormality in a first-degree relative.

PHYSICAL EXAMINATION

A careful, stepwise examination is crucial, including performance of a dynamic cardiac exam.

General appearance, including assessment of growth and maturation
Pulses in upper and lower extremities
Blood pressures in arm and leg with an appropriate-size blood pressure cuff
Palpation: (a) A thrill, heave, or lift over the precordium or suprasternal notch is usually pathologic; (b) Increased intensity and/or lateral displacement (away from the midclavicular line) of the point of maximal impulse suggests left ventricular (LV) enlargement.
Auscultation (see individual diagnoses for details):
- First heart sound (S₁): S₁ is produced by closure of the mitral and then the tricuspid valve and is best heard at the cardiac apex. Splitting of S₁ can be a normal finding. However, auscultation of another sound close to S₁ is usually either a fourth heart sound (S₄) or an ejection click.
- Second heart sound (S₂): The first component (aortic valve closure, A₂) and the second component (pulmonary valve closure, P₂) of S₂ should be of equal intensity. Normally, there is respiratory variation or physiological splitting of the S₂, with widening of the separation with inspiration and narrowing or disappearance of the split with exhalation. Wide, fixed splitting suggests right ventricular (RV) volume overload such as seen with an atrial septal defect (ASD). A single S₂ is also abnormal.
- Third heart sound (S₃): S₃ may be a normal finding in adolescents and young adults (AYAs), and is more prominent in hyperdynamic states.
- Fourth heart sound (S₄): S₄ may be normal in older adults, but is almost always pathologic in AYAs. Practically, the distinctions can be challenging and influenced by heart rate and clinical context.
- Clicks: Sharp, high-frequency sounds that are important clues to organic disease
- Murmurs: Assess murmur characteristics, including timing, loudness, length, tonal quality, and location. All diastolic murmurs, except venous hums, should be considered pathologic.

DIAGNOSTIC CLUES SUGGESTIVE OF INNOCENT (NORMAL) MURMURS

History: Asymptomatic, no family history of cardiac disease
Physical examination: Normal, other than the presence of the murmur
Timing of murmur: Early systolic; almost never diastolic or holosystolic
Intensity: Usually grade 1 to 3/6, and often changing with position (louder in supine position and quieter with sitting or standing)
Quality: Vibratory; no clicks. There is physiological splitting of S₂.
Location: May vary, but frequently at lower or upper left sternal border (LSB), without extensive radiation

TYPES OF INNOCENT (NORMAL) MURMURS

Still’s Murmur

A grade 1 to 3/6 low-to-medium-pitched midsystolic murmur with a vibratory or musical quality best heard at lower LSB. The murmur decreases with sitting or standing.
Still’s murmur is differentiated from hypertrophic cardiomyopathy (HCM) because the murmur decreases with standing,
and is less harsh than a murmur associated with a ventricular septal defect (VSD).

Pulmonary Flow Murmur

A grade 1 to 3/6 short crescendo-decrescendo midsystolic murmur best heard at the upper LSB, between the second and third left intercostal spaces. The murmur is decreased by inspiration and sitting and is often heard in the setting of tachycardia due to fever, anxiety, or exertion.
A pulmonary flow murmur is differentiated from valvular pulmonary stenosis by the absence of a click and from an ASD because S₂ splits normally.

Cervical Venous Hum

A medium-pitched, soft, blowing continuous murmur heard best above the sternal end of clavicle, at the base of the neck
The murmur is increased by rotating the head away from the side of the murmur. The murmur is decreased by jugular venous compression or supine position—unique for a normal murmur.

Supraclavicular (Carotid) Bruit

This is a short, high-pitched early systolic murmur, usually grade 2/6, heard best above the clavicles with radiation to the neck while the adolescent or young adult is sitting. The murmur is decreased by hyperextending the shoulders (bringing the elbows behind the back).

DIAGNOSTIC CLUES SUGGESTIVE OF PATHOLOGIC MURMURS

History: Growth failure, decreased exercise tolerance, exertional syncope or near-syncope, exertional chest pain³
Physical examination: Clubbing, cyanosis, decreased or delayed femoral pulses, apical heave, palpable thrill, tachypnea, inappropriate tachycardia
Murmur: Diastolic, holosystolic, loud or harsh, extensive radiation, increases with standing, associated with a thrill, abnormal S₂ (Table 16.1)

MURMURS ASSOCIATED WITH STRUCTURAL HEART DISEASE

Mildly symptomatic congenital heart disease may not be recognized until adolescence, particularly in underserved populations (Table 16.2).

Atrial Septal Defect

Physical examination: Signs and symptoms depend on shunt size.
- Hyperdynamic precordium with RV lift with sizable shunt; no thrill
- Widely split and fixed S₂
- Pulmonary flow murmur: Grade 2 to 3/6 systolic ejection murmur at upper LSB
- Mid-diastolic rumble at lower LSB

Further evaluation

Electrocardiogram (ECG): Right axis deviation, RV conduction delay (rSR′ pattern), right atrial enlargement, or RV hypertrophy
Chest x-ray: Mild to moderate cardiomegaly with increased pulmonary vascularity
Echocardiogram: Diagnostic with visualization of location and size of defect
Cardiac magnetic resonance imaging allows excellent imaging of the atrial septum and RV volume.

TABLE 16.1 Types of Pathologic Murmurs

Murmur Type	Characteristics	Common Defects
Systolic ejection	Crescendo-decrescendo Begins after S₁; ends before S₂ Best heard with diaphragm	Aortic stenosis Pulmonary stenosis Coarctation of the aorta ASD
Holosystolic	Begins with and obscures S₁ Ends at S₂ Heard at LSB or apex	VSD Mitral regurgitation
Early diastolic	Decrescendo Begins immediately after S₂ High-medium pitch	Aortic insufficiency Pulmonary insufficiency
Mid-diastolic	Low pitch Rumble Best heard with bell	ASD VSD Mitral stenosis
Continuous	Extend up to and through S₂ Continue through all/part of diastole Best heard with diaphragm	PDA
ASD, atrial septal defect; LSB, left sternal border; VSD, ventricular septal defect; PDA, patent ductus arteriosus.

Management: Both surgical closure and transcatheter device closure are safe, effective, and popular management choices.

Ventricular Septal Defect

Physical examination: Shunt volume determines findings.
- With increasing shunt size, the precordium becomes increasingly hyperdynamic. A thrill may be present with either a large or small shunt.
- S₂ is normal with small shunts, accentuated with larger shunts. An S₃ may be present. A loud P₂ (suggesting pulmonary hypertension) is a worrisome finding.
- Grade 2 to 3/6 holosystolic murmur at lower LSB
- Mid-diastolic rumble at the apex with large shunts
Further evaluation
- ECG: Normal in small defects; LV hypertrophy with large defects
- Chest x-ray: Normal in small defects; cardiomegaly with increased pulmonary vascularity in large defects
- Echocardiogram: Provides anatomical detail of location and size of defect; color Doppler permits visualization of very small defects.
Management: Depends on RV pressure and may require catheterization to make appropriate therapeutic decisions. Prophylaxis for subacute bacterial endocarditis (SBE) is no longer recommended for VSD.

Patent Ductus Arteriosus

Physical examination: Shunt volume determines findings.
- Normal precordium with small shunt; hyperdynamic with a thrill with large shunt
- Grade 2 to 4/6 continuous murmur at upper LSB
- Wide pulse pressure and bounding pulses with large shunt

Further evaluation

ECG: Often normal. LV hypertrophy seen if left-to-right shunting is significant

TABLE 16.2 Clues to Specific Organic Cardiac Lesions

Diagnosis	Auscultation	Other Findings	Chest X-ray	ECG
Patent ductus arteriosus	Continuous murmur LUSB and subclavicular area	Wide pulse pressure Bounding pulses	Prominent pulmonary artery	Normal LAE/LVH
ASD	Fixed, widely split S₂ Systolic ejection murmur at LUSB Mid-diastolic rumble at LLSB	RV lift	Prominent RV outflow	Incomplete RBBB (rSR′ pattern)
Pulmonary stenosis	Systolic ejection click (mild PS) P₂ delayed and soft SEM at LUSB	RV lift Thrill at LUSB	Prominent RV outflow Poststenotic dilation	RVH RAE
Aortic stenosis	Early systolic murmur RUSB, transmitted to neck Systolic ejection click (mild AS) Soft A₂	LV lift Decreased pulses	LVE	LVH
Mitral regurgitation	Holosystolic murmur with radiation to axilla; soft S₁	LV lift	Large LA and LV	Bifid P waves Left axis deviation
MVP	Midsystolic click; mid- or late systolic murmur			Abnormal T waves Arrhythmias
Hypertrophic cardiomyopathy	Midsystolic murmur at LLSB, increased with standing and decreased with Valsalva maneuver	Rapid carotid upstroke	±LVE ±LAE	LVH ±Q waves
VSD	High-pitched, harsh holosystolic murmur at LLSB	Thrill at LLSB	Normal	Normal (if small VSD)
Pulmonary hypertension	Loud P₂ No murmur or regurgitant murmur at LLSB	Clubbing	Variable	RAE RVH
Coarctation of aorta	Continuous/systolic precordial murmur Systolic ejection click from bicuspid aortic valve	SBP lower in legs than arms Decreased/delayed femoral pulses	Rib notching Increased pulmonary markings	LVH
ECG, echocardiogram; LUSB, left upper sternal border; LAE, left atrial enlargement; LVH, left ventricular hypertrophy; LLSB, left lower sternal border; RV, right ventricular; RBBB, right bundle-branch block; PS, pulmonic stenosis; RVH, right ventricular hypertrophy; RAE, right atrial enlargement; SEM, systolic ejection murmur; RUSB, right upper sternal border; AS, aortic stenosis; LV, left ventricular; LA, left atrium; LVE, left ventricular enlargement; VSD, ventricular septal defect.

Chest x-ray: Cardiomegaly and increased pulmonary vascularity with large shunt
Echocardiogram: Visualization with two-dimensional and color Doppler imaging

Management: Cardiac catheterization is rarely required for diagnosis but is commonly done for coil or device occlusion.

Valvular Pulmonary Stenosis

Physical examination: Severity of obstruction determines findings.
- RV lift with systolic thrill at upper LSB in more severe forms
- Systolic ejection click at upper LSB, which is louder with expiration (more difficult to hear with severe stenosis)
- S₂ normal or widely split S₂, depending on severity of stenosis
- Grade 2 to 4/6 harsh systolic ejection murmur at upper LSB; may radiate to the lung fields and back
Further evaluation
- ECG: Normal, with progression to RV hypertrophy (upright T wave in lead V1) as stenosis increases
- Chest x-ray: Prominent pulmonary artery segment with normal vascularity
- Echocardiogram: Permits evaluation of valve morphology
- Cardiac catheterization is rarely required for diagnosis.
Management: Treatment of choice is balloon pulmonary valvuloplasty.

Valvular Aortic Stenosis

Physical examination: Severity of obstruction determines findings.
- Prominent apical impulse and systolic thrill (at upper RSB or suprasternal notch)
- Intensity of S₁ may be diminished due to poor ventricular compliance.
- Systolic ejection click at lower LSB/apex that radiates to aortic area at upper RSB; no respiratory variation
- Grade 2 to 4/6 long, harsh systolic crescendo-decrescendo ejection murmur at upper RSB
- High-frequency early diastolic decrescendo murmur of aortic regurgitation
- Careful assessment for features of associated Turner or Williams syndrome
Further evaluation
- ECG: Normal to LV hypertrophy, with strain pattern (ST segment depression and T wave inversion in left precordium) indicating severe stenosis
- Chest x-ray: Normal heart size with prominent ascending aorta
- Echocardiogram: Permits evaluation of valve morphology and determination of level of stenosis; 70% to 85% of stenotic valves are bicuspid.
- Cardiac catheterization is rarely required for diagnosis.
Management: In select cases, aortic balloon valvuloplasty may be an initial palliative procedure.

Hypertrophic Cardiomyopathy (Fig. 16.1)

Physical examination
- Careful assessment for features of skeletal myopathy
- Normal to hyperdynamic precordium with increased LV impulse, dynamic thrill
- Auscultation may be normal. Dynamic examination demonstrates systolic ejection murmur at the lower LSB with increasing intensity in standing position and decreasing intensity with squatting or Valsalva maneuver.
- Dynamic murmur of mitral insufficiency or LV outflow obstruction
Further evaluation
- ECG: Normal in some cases. LV and/or septal hypertrophy, ST-T wave changes, and atrial enlargement may be seen.
- Chest x-ray: May show cardiomegaly, but is rarely indicated.
- Echocardiogram: Diagnostic, with excessive LV wall thickness, impaired ventricular filling, variable degrees of LV outflow tract obstruction, and variable systolic anterior motion of the mitral valve
Management: Management of HCM remains problematic, but may include implantable defibrillators, surgical or catheter treatment, or drug therapy. The adolescent or young adult is restricted from competitive sports. Prophylaxis for SBE is no longer recommended.

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