Definition
• Result of turbulent blood flow; can be 2/2 ↑ blood flow (fever, anemia), abn cardiac structures (abn valve, cardiac defect), or combination
• 50–70% seen annual exam, sports physicals, etc. w/ murmur on exam but only 0.8–1% of pop w/ structural congenital heart disease (Pediatr Rev 2007;28:e19)
Cardiac Examination (Pediatr Rev 2007;28:e19)
• Observation for syndromic appearance, central cyanosis, breathing, JVP
• Palpation for thrills and point of max impulse for displacement, hyperdynamic flow
• Pulse exam: Bounding (inc pulse pressure; PDA, AR, hyperthyroid, AVF), pulsus
parvus (weak)/tardus (late) in AS, unequal in all 4 ext (aortic coarc)
• Abdominal exam: Hepatosplenomegaly (CHF), pulsatile liver (TR)
• Auscultation characterizing S1 (AV valves) and S2 (aortic and pulmonic often split)
• S3 (rapid filling of ventric) often normal in children; sounds like slosh-ing-in
• S4 (atrial contraction against stiff ventricle) always pathologic; sounds like a-thick-wall
• Heart sound order; S4 --- S1 ----S2----S3; S2 nml split to A2--P2; can mistake for S3
-----slosh-ing---in
a------thick-wall----
• Murmurs: Define timing (systolic vs. diastolic; early, mid, late), intensity, location, quality, configuration (crescendo, decrescendo, etc.), duration
• Systolic: Holosystolic (involves S1, cont to S2 at same intensity) and heard w/ AV valve regurg or VSDs; ejection murmurs (begin after S1 w/ cres-decres) and related to flow in great vessels (Pediatr Clin North Am 2004;51:1515)
• Diastolic: Almost always pathologic (aside from venous hum)
• Continuous: Flow through vessel/communication distal to aortic/pulm valves
• Pathologic (PDA; continuous machinery murmur) or benign (venous hum)
Innocent Murmurs of Childhood (Circulation 2005;111:e20; Pediatr Clin
North Am 2004;51:1515)
• Stills murmur: Most common innocent murmur in children; 1st described in 1909
• Typically heard in patients aged 2–6 yo, but can be heard in infants and adolescents
• Vibratory systolic murmur, low pitched, best at LLSB radiating to apex, no thrill
• 2/2 turbulence in LV outflow tract; change w/ position and dec w/ Valsalva
• Pulmonary flow murmur: Cres-decres, early to mid-peaking systolic at LUSB
• Rough & dissonant, best heard in supine position; inc w/ expiration, dec upright
• Can be difficult to distinguish from ASD murmur but w/ ASD have fixed split S2
• Pulm stenosis distinguished by possible presence of thrill, ejection click, soft S2
• Peripheral pulmonary artery stenosis: Common <1yo, usually gone by 6 mo
• Low/mod-pitched ejection murmur in early/mid systole best at axilla or back
• In utero pulm outflow tract well developed, pulm arterial branches comparatively underdeveloped and arise at sharp angles, which resolves w/ growth
• May be difficult to distinguish btw this and pathologic periph pulm artery stenosis w/ Williams or rubella syndrome; murmur may persist beyond S2 w/ these
• Supraclavicular flow murmurs: Cres-decres harsh, high-pitched 2/2 nml bld flow in aorta and head/neck vessels; hear best above the clavicles (e.g., over carotids)
• Same sitting or supine; diminished w/ shoulder girdle hyperextension (arms back)
• Aortic systolic flow murmur: Systolic ejection in aortic area 2/2 increased‚ cardiac output; anxiety, anemia, hyperthyroidism, fever, extreme fitness
• If murmur inc w/ dec preload (Valsalva, squat to stand) → HOCM
• Venous hum: Most common type of continuous murmur and benign
• Best at infraclavicular region while sitting or standing; usually > on R side
• Diminished w/ supine position or pressure over jugular vein
Pathologic Murmurs (Circulation 2005;111:e20)
• Systolic—usually longer and louder than innocent counterparts
• Pansystolic: Involves/obscures S1; if constant; VSD, MR, TR; if crescendo, then PDA
• Ejection (AS, PS): Signs of pathology are presence of ejection click, abn S2 split
• Assess pulses, presence of cardiac failure (JVD, etc.), diastolic murmur as well
• Diastolic: W/ exception of venous hum, all diastolic murmurs are pathologic
• Often need to reposition patient to best auscultate (sitting up leaning forward for aortic sounds and left lateral decubitus to best hear mitral sounds)
• Early: Usually decres; assoc w/ aortic or pulmonic regurgitation
• Mid: Cres-decres 2/2 inc flow across nml MV/TV or 2/2 MS/TS
• Late: Cres and also assoc w/ mitral or tricuspid stenosis (MS/TS)
• Continuous: Harsh machine-like murmur classic for PDA
Further Evaluation (Circulation 2005;111:e20)
• Depends on clinical assessment of patient; if asymptomatic, exam is usually sufficient
• Echo is gold standard to assess cardiac structure; ancillary testing w/ EKG or CXR may be helpful; some suggest referral to pediatric cardiology before imaging