Nikhil K Chanani MD Murmurs: Do you hear what I hear? When does it matter?
2 Audience Poll You are examining a 5 day old and find either: A) a 2/6 systolic murmur in an otherwise asymptomatic child B) a saturation of 89% in an otherwise asymptomatic child with no murmurs C) poor pulses and mottled skin in a distressed infant with no murmurs Which is least likely to have hemodynamically significant cardiac disease?
3 Background Up to 2/3 of children will have a murmur heard at some point in their childhood Incidence of congenital heart disease is 8/1000 This means less than 2% of all murmurs are associated with congenital heart disease As many as 80% of heart lesions are missed during initial neonatal exam* * Emslie et al, Examination for cardiac malformations at six weeks of age. Arch. Dis. Child Fetal Neonatal ed. 1999; 80: F46.
4 A cardiac murmur is the sound of turbulent blood flow. A murmur does not necessarily indicate heart disease. The clinician should emphasize this fact to the patient’s family. A murmur is merely one part of a complete cardiovascular assessment. History, vital signs, physical diagnosis, diagnostic testing
5 Auscultation S1: closing of mitral & tricuspid valves Normally single heard best at apex or LLSB Split S1 uncommon Conduction delay: RBBB, LBBB Valvular problem, ex: Ebstein’s
6 Auscultation S2: closing of aortic & pulmonary valves Physiologic splitting, varies with respiration Heard best at LUSB Physiologic demo Abnormal S2 Widely split Narrowly split Single S2 Paradoxically split Abnormal intensity
7 Auscultation S3: rapid ventricular filling Occurs soon after S2 Best heard at the apex or LLSB May be normal in older children (not infants!) Dilated ventricles large shunts dilated cardiomyopathy myocarditis
8 Auscultation S4: increased atrial pressure against stiff ventricle Best heard at the apex Never normal in children Immediately prior to S1 Indicates poor ventricular compliance HTN, decreased ventricular compliance HCM
9 Auscultation Clicks Ejection click Sounds like split S1, but heard at base Dysplastic semilunar valve, dilated great artery Midsystolic click Heard at apex in MVP Opening snap Early diastolic, at apex in mitral stenosis Friction Rub Pericarditis, effusion
10 Physical exam - Murmurs Sound created by turbulant bloodflow through heart and great vessels Murmurs grade/intensity Timing Location Radiation Shape Quality frequency/pitch
12 Murmurs Diastolic Murmurs: between S2 & S1 Early: decrescendo AI and PI Mid/Late: low pitched, may start with S3 AV valve stenosis or increased flow Continuous Murmurs: continue through S2 AP or AV connections: PDA, AVM, shunts Combination systolic and diastolic To-fro murmurs: AS and AI, PS and PI Venous hum
13 Grading Murmurs Without thrill Grade 1: very faint, barely audible Grade 2: soft but easily heard Grade 3: intermediate
14 Grading Murmurs (cont.) With thrill Grade 4: loud, with a palpable vibration (thrill) Grade 5: very loud, audible with edge of stethoscope on chest Grade 6: very loud, audible with stethoscope just off chest Diastolic murmurs are graded from 1-4
15 Systolic Murmurs A systolic murmur generally represents forward flow through the aortic or pulmonary valve backward flow through the mitral or tricuspid valve flow through the VSD innocent (Still’s) murmur through the LV cavity innocent flow murmurs through aortic and pulmonary valves with anemia, bradycardia, fever or hyperthyroidism
16 Diastolic Murmurs A diastolic murmur generally represents forward flow through the mitral or tricuspid valve backward flow through the aortic or pulmonary valve innocent flow murmurs across mitral or tricuspid valve with anemia, bradycardia, fever, or hyperthyroidism
17 Continuous Murmurs Venous hums Patent ductus arteriosus Collateral vessels Coronary arterial fistulae or any arteriovenous fistula Surgical systemic arterial to pulmonary arterial shunts Aorticopulmonary windows
18 Innocent Murmurs The following is a list of innocent murmurs and their characteristics in children and adolescents:
19 Innocent Murmurs (cont.) Still’s murmur Most common, vibratory, musical in nature; LLSB-apex; louder supine; murmur decreases with Valsalva strain; R/O VSD, MR, sub-AS
20 Innocent Murmurs (cont.) Supraclavicular arterial bruit Above clavicles; murmur is low intensity and in early systole; possible associated thrill; R/O AS, PS, VSD, coarctation
21 Innocent Murmurs (cont.) Venous hum Continuous; gravity-dependent; due to turbulent subclavian, innominate vein and SVC flow; murmur disappears when patient supine; R/O anemia, hyperthyroidism, cerebral AVM
22 Innocent Murmurs (cont.) Peripheral pulmonary stenosis (newborn) Base, axillae, back bilaterally; relative PA hypoplasia and bracing; murmur persists until three to six months; R/O ASD, PDA, TOF
31 Pathologic Murmurs (cont.) Loud murmur in delivery room/nursery: outflow tract stenosis; AV valve insufficiency Every baby has a large PDA after delivery. This should not, however, cause an audible murmur.
32 Summary “Listen in all areas for heart murmurs. First in systole and then in diastole. Concentrate on dissection. After much practice, this should become automatic.” From “Listening to Heart Murmurs in Infants and Children” by Jerome Liebman, MD