Innocent pediatric murmurs

Background

Goal to distinguish innocent (benign) murmurs from clinically significant pathology
Red flag features that may point to pathology, not innocent murmurs:
- Poor weight gain: check height and weight- left-to-right can cause decrease in weight, but are usually symptomatic
- Color - cyanosis of hands, feet, perioral on exertion
- Feeding - fatigue or short feeding times for infants- perspiring, grunting, coughing, tachycardia while feeding. Severe CHF may show at rest deep breathing with dyspnea with distress
- Enlarged heart (ie ASD) can cause bulging of chest
- Older kids - activity causing dyspnea/cyanosis- keeping up with peers, grunting, coughing, tired from stairs. syncope/presyncope, fatigue, palpitations/angina can occur with hypertrophic cardiomyopathy
- Yet older - Aortic valve with rheumatic fever, myocarditis (history of URI), endocarditis (IV drug use)
- Pregnancy history - Maternal diabetes (ASD, coarctation of the aorta, cardiomyopathies), CMV, Coxsackie B5, warfarin, AEDs use, EtOH (ASD,VSD), prematurity (PDA)
- Worry when - family history of [[HCM]]/sudden death and prominent apical thrust (indicates LVH)

Most innocent murmurs are
- Not holo or diastolic
- Not >grade III
- Hockey stick dist
- Normal S1 & S2

Mid-Systolic, best at left lower sternal border, likely from harmonic vibrations of LV outflow tract (chordae tindinae)
All ages, particularly young school age
Low pitch, musical
Decreased with inspiration, sitting, standing. Not a VSD- not regurgitant or with thrill

Systolic best at left upper sternal border, minor turbulence in RV outflow tract and main pulmonary artery
Often infants and preschool age. Higher pitched than still's, less musical
Not PS- no ejection click, no increased RV impulse. no wide s2 split
Not Pulm M of ASD, no fixed splitting, no diastolic tricuspid flow rumble, no increased RV impulse
Decreased on inspiration/sitting/standing

Systolic ejection murmur from turbulence in pulmonary artery branches (one or both)
Medium pitch
Physiologic in neonates, becoming audible at L,R,B USB between 0-2wks
Transmits well to back and axilla. common in premature; disappears early in infancy
Not PS- no ejection click, no increase in RV impulse

Systolic ejection murmur of medium pitch from physiologic turbulence of carotid/subclavian and heard at base of neck
Can be palpable. Disappears on hyperextension of shoulders
Not AS which is loudest at URSB with systolic thrill, sometimes with click

Continuous murmur from turbulent flow in SVC heard at L,R,or B infraclavicular position while sitting/standing
Not PDA (bounding pulse, systolic>diastolic sound) or AV malformation
Disappears in recumbent position, rotation of head, by pressure at jugular