Pediatric Heart Sounds and Murmurs

Workup of Murmur

History

• Pregnancy
• Infection: rubella during the first trimester, also CMV, herpes, coxsackievirus B
• Drugs: medicines, alcohol, smoking
• Illness: IDM (associated with transposition of the great arteries), maternal SLE, maternal cardiac disease
• Genetic: Marfan, Holt-Oram, Downs (Trisomy 21), Turner Syndromes
• Prematurity: associated with PDAs
• Birth
• Cyanosis, resucitation, murmur at birth
• Growth and Development
• Failure to gain weight
• Feeding problems (fatigue and shortness of breath): feedings take a long time
• "Does not gain weight or grow like others"
• "Breathes heavily", tachypnea, dyspnea
• "Cannot keep up", decreased exercise tolerance
• Cyanosis
• Anoxic spells: crying, then SOB, cyanosis, unconsciousness or seizures, consider Tetrology of Fallot (need to distinguish from breath-holding spells)
• Squatting when tired (also, common in TOF)
• Eyelid edema (ankle edema is rare)
• Lower respiratory tract infection
• Murmur, when was it first heard?  with febrile illness?  history of pharyngitis?
• Chest pain
• Uncommon in children
• AS: pain during activity
• Obstructed pulmonary vessels or mitral valve prolapse: pain without activity
• Severe pulmonary valve stenosis: pericarditis; Kawasaki disease
• Relation to activity, duration, character of pain, distribution of pain, relation to respiration, association with fainting or palpitations
• Medications (eg, albuterol)
• Rheumatic fever (arthritis, Group A Strep. pharyngitis, carditis, chorea, erythema marginatum, subcutaneous nodules, fever, elevated ASO)
• Neurologic symptoms: stroke, syncope, headaches (consider brain abcess)
• Family history of CHD

Examination

• Observe undisturbed infant/child in quiet setting
• record and evaluate vital signs (using norms for age)
• plot measurements
• note dysmorphic features
• cyanosis (central cyanosis is a more reliable sign of hypoxia than peripheral cyanosis)
• respiratory rate^*
• chest wall deformities
• sweaty forehead
• tachycardia
• compare upper and lower extremity pulses; quality of pulses (bounding pulses in aortic runoff lesions such as PDA or AI; weak pulses distal to stenotic areas or poor contractility)
• apical impulse, PMI, hyperactivity of precordium, thrill
• hepatomegaly^*
• splenic enlargement (think bacterial endocarditis)
• blood pressure: cuff covers the upper 3/4 of upper arm or leg; bladder 20-25% longer than the circumference of the limb

Auscultation

The four cardinal heart sounds
• S1:  First heart sounds /lub/ is produced  by the closure of the AV (mitral and tricuspid) valves; low-pitched and relatively long sound; preceeds carotid pulse; best heard at the apex
• S2:  Second heart sound /dub/ is produced by the closure of the aortic and pulmonic valves; shorter and sharper sounds; splits during inspiration (normally, A2 preceeds P2), heard when pulmonary resistance falls several weeks after birth
• S3:  Third heart sound is a normal finding in children and young adults; caused by sudden limitation of longitudinal expansion of the ventricular wall; brief low pitched sound in mid-diastole; audible in about 6-10% of young people
• S4:  Fourth heart sound ("atrial sound" or "atrial gallop"; presystolic gallop) is produced by vibrations in expanding ventricles during rapid diastolic filling when atria contract; late diastolic low pitched low intensity diastolic sound; usually requires confirmation that it is normal (uncommonly audible)

• Chest, head, back, abdomen
• "Listen everywhere in a systematic fashion so that no area is missed.  The specific area where an abnormality is heard best is then described".
• Bell and diaphragm in all areas
• Sitting and Lying, after exercise
• Left lateral decubitus position accentuates mitral murmurs
• Murmurs
• Grade I: barely audible
• Grade II: audible, the majority of murmurs
• Grade III: stronger than II, may have thrill
• Grade IV:Must have thrill
• Grade V:Audible with on edge of the stethoscope on the chest
• Grade VI:Audible with stethoscope off the chest
• Oxygen saturation (pulse oximetry, right arm preductally, other site such as leg postductally)
• Hyperoxygenation test
• "Estimate the effective pulmonary blood return (the percent of venous return that goes to the lung to be oxygenated and is returned to systemic circulation)
• Placing patient in 100% oxygen will improve oxygen saturation in lung disease, but will make little improvement in cardiac disease
• Must sample oxygen saturation above the ductus, the right arm (or, for blood gas, right radial artery) is most convenient location
• If pO₂ remains less than 150 mmHg on 100% FiO₂, suspect cyanotic heart disease
• Hemoglobin, Hematocrit, RBC count
• CXR: pulmonary vasculature, heart size and silohuette
• Egg on a string with increased pulmonary markings: TGA

Boot-shaped heart with decreased pulmonary markings: TOF

• Normal sized heart with increased pulmonary markings: TAPVC
• Huge heart with decreased pulmonary markings: Ebstein's anomaly (leaky tricuspid)
• Echocardiogram

*Heart failure

Failure of the heart pump to pump enough blood to meet the metabolic needs of the body.

• Left heart failure:  Pulmonary edema results; presents often as tachypnea (not rales or cough)
• Right heart failure: Most common manifestation is hepatomegaly

Innocent Murmurs

• 2-57% of infants
• 6-90% of school age children
• Prevalence of congenital heart disease is 3.7 to 3.9/1000 children
• Only 2-7% of murmurs in children represent heart disease
• Family history of left sided heart disease makes chance of heart disease greater
• Stills murmur
• Best heard between LLSB and apex, radiating out towards right base
• Low pitched, groaning, twanging, early to mid systolic murmur
• Decreased by Valsalva or standing
• DDX: hypertrophic obstructive cardiomyopathy (HOCM) or small VSD, AS
• Arterial Supraclavicular Bruit
• Best heard in the supraclavicular fossa, right > left
• Audible in the lower neck, does not radiate
• Brief early systolic ejection bruit
• Reduced with shoulder hyperextension
• No ejection sound
• Attributed to turbulence at origins of the brachiocephalic vessels
• Innocent Pulmonary Flow Murmur
• 15% of all innocent murmurs of childhood
• Maximal at ULSB
• Does not radiate to back or neck
• No ejection sound, abnormality of S2 or increased right ventricular impulse
• Blowing medium pitched midsystolic
• DDX: ASD, PS, TR, HOCM
• Cervical Venous Hum
• Extremely common
• Soft blowing high pitched continuous
• Best in infraclavicular areas when seated
• Obliterated by turning head and/or compressing neck ipselaterally
• Mammary Souffle
• Adolescent and young adult women
• Continuous or diamond shaped systolic murmur in second right or left intercostal space in midclavicular line
• Decreases with upright posture or pressure with stethoscope
• Most common during lactation or pregnancy

The "Five Murmurs of Dr. Kuehl"

• Two systolic
• Regurgitant murmurs (goes from S1 to S2), all abnormal
• Stenotic or ejection murmurs (murmur does not begin until after S1 and may extend beyond S2); increases and then decreases in amplitude
• Two diastolic
• Aortic or Pulmonary insufficiency, decreshendo after P2
• Mid-diastolic filling
• Continuous
• e.g. PDA: continuous murmur at upper left sternal border
• When to worry about a murmur:  Significant history; loud/harsh murmur, diastolic murmur, holosystolic murmur, associated cardiac findings (loud single S2, gallop rhythm, diminished femoral pulses, ejection click, cyanosis, associated with FTT, CHF or other systemic illnesses)

References

• Lehrer, Steven.  1992.  Understanding Pediatric Heart Sounds.  WB Saunders (taped heart sounds with companion book)
• Devine.  A basic guide to cyanotic congenital heart disease.  Contemporary Pediatrics, October 1998.
• Feit.  The heart of the matter.  Evaluated murmurs in children.  Contemporary Pediatrics, October 1997.
• Sapin.  Recognizing normal heart murmurs: a logic-based mnemonic.  Pediatrics, April 1997.

Acknowledgment