Innocent pediatric murmurs
Background
- 72% of all school-age children have innocent murmurs
- Congenital heart disease- 0.8% of live births
Clinical Features
- 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)
Differential Diagnosis
Valvular Emergencies
Evaluation
- Most innocent murmurs are
- Not holo or diastolic
- Not >grade III
- Hockey stick dist
- Normal S1 & S2
Types
Still's
- 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
Innocent Pulmonary Flow Murmur
- 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
Innocent Pulmonary Branch Murmur of Infancy
- 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
Supraclavicular Bruit
- 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
Venous Hum
- 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
Mammary Souffle
- Blood flow in A and V to engorged breast
- Systolic or continuous, disappears with stethoscope pressure
Cardiorespiratory murmur
- High pitched cooing, anywhere, but especially apex
- Breath sound so not timed to heart, disappear when holding breath