Transcript Nelson – pedi cardiology MURMURS ONLY

Pediatric cardiology
JFK pediatric core curriculum
MGH Center for Global Health
Pediatric Global Health Leadership Fellowship
Credits:
Brett Nelson, MD, MPH
Discussion
• Cardiac evaluation
• Auscultation
• Distinguishing pathologic from innocent
murmurs
• Common innocent pediatric murmurs
• Further work-up of a concerning murmur
Initial cardiac evaluation
• History: poor feeding, diaphoresis, FTT,
family hx
• Vital signs: height, weight, HR, RR
• Inspection: dysmorphism, cyanosis,
clubbing
• Palpation: presence and quality of distal
pulses; precordium for PMI and thrills; liver
• Auscultation
(further cardiac evaluation to follow…)
Auscultation
• Rate & regularity
• Heart sounds
– Focus particularly on intensity and quality of S2 and
for presence of extra heart sounds (S3, S4)
• Murmurs…
• Clicks
– Abnormal valvular sounds (e.g. ejection clicks in early
systole, MVP in mid/late systole)
• Rub
– Associated with pericarditis; scratchy sound best
heard at apex (may diminish if pericardial effusion
becomes large)
Auscultation
Heart sounds
• S1: closing of the AV valves
– mitral then tricuspid
• S2: closing of the semilunar valves
– aortic then pulmonary
• S3: ventricular overload
– “TEN-NE-see”: S1, S2, s3
– <40yrs, pregnancy, MR/TR, CHF
• S4: decreased LV compliance
– “ken-TUCK-Y”: s4, S1, S2
– more likely than S3 to be pathologic (HTN, CAD,
cardiomyopathy), although can be normal (athletes)
Murmurs
• Secondary to turbulent blood flow
• Assess:
– Intensity / loudness
– Timing (systolic, diastolic, continuous)
– Location of maximal intensity
– Transmission / radiation
– Quality (high-pitched, blowing, vibratory,
harsh, soft)
Murmurs: grading of intensity
• I barely audible
• II soft, but easily audible
• III moderately loud without thrill; roughly
as loud as S1/S2
• IV loud with a thrill
• V audible with stethoscope barely on
chest
• VI audible with stethoscope off chest
Murmurs: timing
Maneuvers to dynamically
evaluate murmurs
• Inspiration typically increases murmurs originating from
the right heart
– Negative pressure temporarily increases venous return
• Expiration typically increases murmurs originating from
the left heart
– Less LV restriction due to lower RV volumes
• Increasing overall venous return (supine, squatting, legraise) can accentuate flow-type murmurs
– Can also delay MVP click due to “tighter” chordae tendinae
• Standing increases the murmur of hypertrophic
cardiomyopathy (HOCM/IHSS)
– Decreased venous return  smaller LV volume  closer
apposition of LV walls
Distinguishing pathologic
from innocent murmurs
Innocent murmurs
• The prevalence of innocent murmurs in
infants is as high as 60%
– Versus: the incidence of congenital heart
defect is 6 in 1000 (0.6%)
• Innocent murmurs are usually…
– early systolic
– Grade I or II
– poorly transmitted
– Not associated with other findings
Pathologic murmurs (1)
• Murmurs that are…
– Loud (Grade III+)
– Diastolic
– Abnormal heart sounds (e.g. S3/S4 gallop)
– Long in duration
– Systolic and associated with clicks
– Louder upon standing
Pathologic murmurs (2)
• Murmurs that are associated with…
– Abnormal or absent pulses
– Unequal blood pressures
– Cyanosis
– Symptoms (e.g. syncope, chest pain)
– Abnormal EKG / CXR
– Syndromes, dysmorphism, other birth defects
(e.g. CHARGE syndrome, DiGeorge, trisomy
21)
Common innocent murmurs
Still’s murmur
• Most common innocent murmur, usually
found between the ages of 3 and 6
• Thought to be due to turbulence in LV
outflow or to vibration of fibrous tissue
bands crossing LV lumen
• Typically grade II-III, midsystolic, LLSB,
and classically described as “vibratory”
• Decreases with standing
• Increases with fever, exercise, anemia
Pulmonary flow murmur
• Accounts for 15% of all innocent murmurs
• Heard in infants and school-aged children
• Due to turbulent flow at the origin of the
right and left pulmonary arteries
• Grade I-III, midsystolic ejection, heard at
the ULSB, higher pitched than a Still’s
murmur
• Like Still’s, increases with fever, exercise,
and anemia
Peripheral pulmonary stenosis
(PPS) of the newborn
• Due to the physiologic relative stenosis of
the right and left pulmonary arteries
• Usually disappears by 1 year of age
• Grade I-II, midsystolic ejection, heard at
the ULSB with radiation to the axillae and
back
Venous hum
• Seen in preschool-aged children
• Due to turbulence in the jugular venous
system
• Continuous supraclavicular murmur heard
throughout the cardiac cycle (usually right
side > left side)
• Disappears when the patient is supine,
when the head is rotated, or with manual
compression of the neck veins
Supraclavicular arterial bruit
• Due to turbulence in the major brachiocephalic
arteries as these vessels arise from the aorta
• High-pitched, systolic ejection murmur heard
best in the right supraclavicular fossa
• Decreases with raising of the chin, throwing
back the shoulders, or firm pressure on the
subclavian artery
• Increases with slight pressure on the subclavian
artery
Further cardiac evaluation
(as available)
• Four-extremity blood pressures
• Pre- and post-ductal pulse oximetry
– O2 saturation <93% in the lower extremities is
abnormal
– Clinical cyanosis is not seen until saturation <88%
• EKG
• CXR
• Cardiology referral and echocardiogram
(definitive test)
Resources
1.
** Online audio of heart sounds and murmurs **
http://depts.washington.edu/~physdx/heart/demo.html
2.
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7.
Patel J. “Evaluation of Pediatric Murmurs.” San Antonio, TX.
http://www.texasnp.org/resources/2006_conference/PediatricMur
murs%5B1%5D.ppt.
McConnell ME, Adkins SB, Hannon DW. “Heart murmurs in
pediatric patients: when do you refer?” American Family
Physician. November 1999.
http://www.aafp.org/afp/990800ap/558.html.
How to distinguish between innocent and pathologic murmurs in
childhood. Pediatric Clinics of North America. 1984
Park MK. Pediatric Cardiology For Practitioners.
Bricker T. The Science and Practice of Pediatric Cardiology.
Allen H. Moss & Adams: Heart Disease in Infants and Children.