Cardiology Laboratory

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Blood Pressure Measurement

  • All children >3 years old should have blood pressure (BP) measured as part of their physical exam.
  • If <3 years old, measure BP if there are comorbidities present that predispose them to hypertension (congenital heart disease, NICU stay, recurrent UTI, proteinuria, renal disease).
  • Measure BP in right upper arm for purposes of consistency, comparability to standard tables, and to avoid a spurious value in cases of coarctation.
  • BP by auscultation is the preferred method.
  • Abnormal BPs obtained by oscillometry should be confirmed by auscultation.
  • Optimal BP cuff size (Table 1):
    • Bladder length covers 80–100% of the circumference of the arm.
    • Bladder width covers 40% of the upper arm circumference.
  • Refer to BP standards based on gender, age, and height that now include 50th, 90th, 95th, and 99th percentiles (Tables 2 and 3).
  • Hypertension is defined as average systolic BP (SBP) and/or diastolic BP (DBP) that are ≥95th percentile for gender, age, and height on three occasions.
  • Prehypertension: If the SBP or DBP is ≥90th percentile and <95th percentile, it is called “Prehypertension.”
  • Aortic coarctation: If suspected, check BP in all four extremities. A difference >10 mm Hg between upper and lower extremity BPs is pathologic and suggests the presence of aortic coarctation, aortic arch hypoplasia, or interrupted aortic arch.
Table 1. Recommended Dimensions for BP Cuff Bladders
Age RangeWidth, cmLength, cmMaximum Arm Circumference, cma
Newborn4810
Infant61215
Child91822
Small adult102426
Adult133034
Large adult163844
Thigh204252

aCalculated so that the largest arm would still allow the bladder to encircle arm by at least 80%.

BP, blood pressure.

Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.

Table 2. BP Levels for Boys by Age and Height Percentile
SBP, mm HgDBP, mm Hg
Percentile of HeightPercentile of Height
Age, yBP Percentile5th10th25th50th75th90th95th5th10th25th50th75th90th95th
150th8081838587888934353637383939
90th9495979910010210349505152535354
95th989910110310410610654545556575858
99th10510610811011211311461626364656666
250th8485878890929239404142434444
90th979910010210410510654555657585859
95th10110210410610810911059596061626363
99th10911011111311511711766676869707171
350th8687899193949544444546474848
90th10010110310510710810959596061626363
95th10410510710911011211363636465666767
99th11111211411611811912071717273747575
450th8889919395969747484950515152
90th10210310510710911011162636465666667
95th10610710911111211411566676869707171
99th11311411611812012112274757677787879
550th9091939596989850515253545555
90th10410510610811011111265666768696970
95th10810911011211411511669707172737474
99th11511611812012112312377787980818182
650th91929496989910053535455565757
90th10510610811011111311368686970717272
95th10911011211411511711772727374757676
99th11611711912112312412580808182838484
750th929495979910010155555657585959
90th10610710911111311411570707172737474
95th11011111311511711811974747576777878
99th11711812012212412512682828384858686
850th9495979910010210256575859606061
90th10710911011211411511671727273747576
95th11111211411611811912075767778797980
99th11912012212312512712783848586878788
950th95969810010210310457585960616162
90th10911011211411511711872737475767677
95th11311411611811912112176777879808181
99th12012112312512712812984858687888889
1050th979810010210310510658596061616263
90th11111211411511711911973737475767778
95th11511611711912112212377787980818182
99th12212312512712813013085868688888990
1150th9910010210410510710759596061626363
90th11311411511711912012174747576777878
95th11711811912112312412578787980818282
99th12412512712913013213286868788899090
1250th10110210410610810911059606162636364
90th11511611812012112312374757576777879
95th11912012212312512712778798081828283
99th12612712913113313413586878889909091
1350th10410510610811011111260606162636464
90th11711812012212412512675757677787979
95th12112212412612812913079798081828383
99th12813013113313513613787878889909191
1450th10610710911111311411560616263646565
90th12012112312512612812875767778797980
95th12412512712813013213280808182838484
99th13113213413613813914087888990919292
1550th10911011211311511711761626364656666
90th12212412512712913013176777879808081
95th12612712913113313413581818283848585
99th13413513613814014214288899091929393
1650th11111211411611811912063636465666767
90th12512612813013113313478787980818282
95th12913013213413513713782838384858687
99th13613713914114314414590909192939494
1750th11411511611812012112265666667686970
90th12712813013213413513680808182838484
95th13113213413613813914084858687878889
99th13914014114314514614792939394959697

BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.

Table 3. BP Levels for Girls by Age and Height Percentile
SBP, mm HgDBP, mm Hg
Percentile of HeightPercentile of Height
Age, yBP Percentile5th10th25th50th75th90th95th5th10th25th50th75th90th95th
150th8384858688899038393940414142
90th97979810010110210352535354555556
95th10010110210410510610756575758595960
99th10810810911111211311464646565666767
250th8585878889919143444445464647
90th989910010110310410557585859606161
95th10210310410510710810961626263646565
99th10911011111211411511669697070717272
350th8687888991929347484849505051
90th10010010210310410610661626263646465
95th10410410510710810911065666667686869
99th11111111311411511611773737474757676
450th8888909192949450505152525354
90th10110210310410610710864646566676768
95th10510610710811011111268686970717172
99th11211311411511711811976767677787979
550th8990919394959652535354555556
90th10310310510610710910966676768696970
95th10710710811011111211370717172737374
99th11411411611711812012078787979808181
650th9192939496979854545556565758
90th10410510610810911011168686970707172
95th10810911011111311411572727374747576
99th11511611711912012112280808081828383
750th9393959697999955565657585859
90th10610710810911111211369707071727273
95th11011111211311511611673747475767677
99th11711811912012212312481818282838484
850th959596989910010157575758596060
90th10810911011111311411471717172737474
95th11211211411511611811875757576777878
99th11912012112212312512582828383848586
950th96979810010110210358585859606161
90th11011011211311411611672727273747575
95th11411411511711811912076767677787979
99th12112112312412512712783838484858687
1050th989910010210310410559595960616262
90th11211211411511611811873737374757676
95th11611611711912012112277777778798080
99th12312312512612712912984848586868788
1150th10010110210310510610760606061626363
90th11411411611711811912074747475767777
95th11811811912112212312478787879808181
99th12512512612812913013185858687878889
1250th10210310410510710810961616162636464
90th11611611711912012112275757576777878
95th11912012112312412512679797980818282
99th12712712813013113213386868788888990
1350th10410510610710911011062626263646565
90th11711811912112212312476767677787979
95th12112212312412612712880808081828383
99th12812913013213313413587878889899091
1450th10610610710911011111263636364656666
90th11912012112212412512577777778798080
95th12312312512612712912981818182838484
99th13013113213313513613688888990909192
1550th10710810911011111311364646465666767
90th12012112212312512612778787879808181
95th12412512612712913013182828283848585
99th13113213313413613713889899091919293
1650th10810811011111211411464646566666768
90th12112212312412612712878787980818182
95th12512612712813013113282828384858586
99th13213313413513713813990909091929393
1750th10810911011111311411564656566676768
90th12212212312512612712878797980818182
95th12512612712913013113282838384858586
99th13313313413613713813990909191929393

BP, blood pressure; SBP, systolic blood pressure; DBP, diastolic blood pressure.

Source: National Heart, Lung, and Blood Institute; National Institutes of Health; U.S. Department of Health and Human Services.

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