Accuracy of Auscultatory Blood PressureMeasurements in Hypertensive and Obese Subjects

POUL EBBE NIELSEN, M.D., Bo LARSEN, M.D., PER HOLSTEIN, M.D.,

AND HASSE L0NSMANN POULSEN, M . D .

SUMMARY In 59 treated or untreated hypertensive subjects and 52 obese subjects (normotensiveor hypertensive), intraarterial blood pressure (BP) was compared to simultaneous auscultatorymeasurements. In the hypertensive group, arm circumference was less than 35 cm compared to over35 cm in the obese subjects. The occluding cuffs were 12 x 35 cm and 15 x 43 cm respectively. Meandifference between auscultatory and intraarterial systolic BP (SBP) was among the hypertensive -8.8 mm Hg (SDD[FF 9.0 mm Hg, range + 13/ - 28) and among the obese - 3.1 mm Hg (SDD(FF 13.8 mm Hg,range + 19/— 49). Mean difference auscultatory-intraarterial diastolic BP (DBP) Phase V was among thehypertensive patients + 10.8 mm Hg(SDD1FF 6.8 mm Hg, range + 29/— 8), and among the obese + 5.5 mmHg (SDDIFF 7.3 mm Hg, range + 20/— 10). Thus, a 15 x 43 cm cuff used in obese subjects with an armcircumference exceeding 35 cm gave quite as reliable measurements as a 12 x 35 cm cuff used in hyperten-sive subjects with "normal" dimension of the upper arm (< 35 cm). It is emphasized that there is a widescatter in the interindividual differences, and it is argued that a comparison between auscultatory andintraarterial BP should be performed in patients with poorly controlled hypertension.(Hypertension 5: 122-127, 1983)

KEY WORDS • blood pressure • measurement of blood pressure • hypertension • obesity

SEVERAL studies have been published concern-ing the difference between direct (intraarterial)and indirect (auscultatory) measurement of bra-

chial artery blood pressure (BP).1"13 In these studiesnearly all the subjects have been normotensive con-trols, and only a few have been treated or untreatedhypertensives. In both obese and nonobese hyperten-sive subjects, we have compared the auscultatory mea-surements with simultaneous short-lasting intraarterialvalues in order to evaluate whether there is an artifactusing the conventional cuff technique. The aims of thepresent study were to compare auscultatory and in-traarterial readings in a group of consecutively referredhypertensive subjects, and to evaluate similar com-parisons performed among obese subjects (hyperten-sive and normotensive).

Material and MethodsA total of 59 treated or untreated hypertensive pa-

tients were investigated (table 1). Before treatment,

From the Department of Internal Medicine, Division of Cardiology,Hvidovre Hospital, and Department of Clinical Physiology, BispebjergHospital, University of Copenhagen, Denmark

Address for reprints: Dr. Poul Ebbe Nielsen, Mindevej 24, DK-2860Soborg, Denmark.

Received February 2, 1982; revision accepted June 24, 1982.

TABLE 1.

SubjectsData from 59 Hypertensive Subjects and 52 Obese

ArmAge circumference Cuff

Sex (yrs) (cm) sizeSubjects M/F (mean/range) (mean/range) (cm)

Hypertensive 37/22 51.0 28 7 1 2 x 3 5(n = 59) (24-70) (22-34)

Obese 18/34 41.0 39 3 15 x 43(n = 52) (18-73) (35-49)

they had auscultatory diastolic BP (DBP) Phase Vgreater than 105 mm Hg, in repeated ambulatory mea-surements. The patients were consecutively referredfrom outpatient clinics and medical wards. All in thehypertensive group had an upper arm circumferenceless than 35 cm on the day of direct and indirect BPmeasurements. With these patients, a 12 X 35 cm armcuff was used.14 If their upper arm circumference wasgreater than 35 cm, they were referred to the obesegroup, where a bigger cufT was used.15

There were 52 obese patients, on whom a cuff 15 x43 cm was used.14' " They were sent to us either be-cause of hypertension or because they were awaitingan intestinal bypass shunt operation for morbid obesityand were to be followed for changes in arm BP beforeand after the weight loss.

122

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

AUSCULTATORY BLOOD PRESSUKEJNielsen et al. 123

Comparison Between Auscultatory andIntraarterial Blood Pressure

The patients were placed in the supine position forabout 15 minutes. Prior to the intraarterial measure-ments, auscultatory BP was measured twice on botharms. In none of the patients did the blood pressure inthe two arms differ more than ± 10 mm Hg for bothsystolic BP (SBP) and DPB (Phase V). Seven patients(three hypertensive and four obese subjects) were ex-cluded from the study due to a difference of more than10 mm Hg between auscultatory BP in the two arms(SBP = 15, 15, 18, and 29 mm Hg; DBP = 1 1 ,11,and 13 mm Hg). In seven patients (one hyperten-sive and six obese subjects), the intraarterial measure-ments could not be performed due to difficulties incannulation of the deep-lying and/or very thin arteries.

Intraarterial MeasurementsIntraarterial measurements in the right arm were

performed after local anesthesia with a sharp needle4-cm long (gauge 21, outer diameter 1.0 mm, innerdiameter 0.7 mm) connected to a Elema-Schonandercapacitance transducer (Postsack, Solna, Sweden)through a rigid polyethylene tube 20-cm long. Theneedle was inserted in the right brachial artery. In allintraarterial tracings, the dicrotic notch was clearlyestablished before the comparison was performed.

Auscultatory MeasurementsTriplicate auscultatory measurements with an ordi-

nary mercury manometer on the left arm were used forcomparison with intraarterial measurements. The cuffwas initially inflated to about 40-50 mm Hg above theexpected SBP. After waiting a few seconds, deflationbegan at a rate of about 5 mm per pulse beat. In the areaaround SBP, the deflation rate was + 15 to — 5 mmHg; the deflation rate changed to about 2 mm Hg perpulse beat, which made possible readings with an ap-proximation of 2 mm Hg. Between the SBP and ex-pected DBP, the deflation rate was about 5 mm Hg perpulse beat, but in the area around DBP Phase V (cessa-tion of Korotkoff sounds), the deflation rate was again

2 mm Hg per pulse beat, thus permitting a reading ofDBP with an approximation of 2 mm Hg. The DBPPhase IV (muffling of the Korotkoff sounds) was notrecorded in the study.

We have used this auscultatory measurement tech-nique for years and have found it applicable to allreadings of auscultatory BP, particularly where meas-urement accuracy is important, such as in clinical tri-als. Before the study, the authors had tested ausculta-tory BP measurements and interobserver variation ofBP readings in a few patients although no systematictechnique for comparison was used by all authors.

In this study when auscultatory SBP and DBP PhaseV were read, the intraarterial tracings were marked bya technician so that the exact intraarterial value couldbe calculated after the comparison. Following themeasurements, the linearity of the transducer-manom-eter system was clarified using increasing fixed pres-sures (ie., 0, 50, 100, 150, 200, 250 mm Hg and thenback to 0, the "staircase-test"). The degree of damp-ing calculated using the square-wave test was about0.3-0.4, i.e., a slighty underdamped system. The nat-ural frequency of the system calculated from thesquare-wave test was about 15 to 20 Hz.

ResultsThe overall results are given in table 2 and figure 1.

In both the hypertensive group and the obese group,auscultatory SBP was on the average a few mm Hgbelow that of intraarterial SBP, the mean differencebeing — 8.8 mm Hg and — 3.1 mm Hg respectively.The individual differences varied considerably as ex-pressed in both SDD1FF and range (table 2).

Among the hypertensive subjects, auscultatory DBPPhase V was on the average + 10.8 mm Hg abovethe intraarterial DBP, and among the obese subjects,+ 5.5 mm Hg above intraarterial DBP. In both groupsthe interindividual differences varied considerably, asexpressed by SDDUT and range (table 2 and fig. 1).

TABLE 2. Comparison Between Auscultatory and Intraarterial BP in 59 Hypertensive Subjects and52 Obese Subjects

Comparison

Subjects

Hypertensive (n = 59)

Mean

SD

Range

Obese subjects (n = 52)

Mean

SD

Range

AuscultatoryBP

(mm Hg)

174.0/108.4

31.4/14.8

128-251/80-138

154.9/92.3

26.5/14.0

108-283/65-142

IntraarterialBP

(mm Hg)

182.8/97.6

23.0/13.9

115-254/74-126

158.0/86.8

37.0/14.2

114-285/64-138

Auscultatory arterialBP

(mm Hg)

-8.8/+10.8

9.0/6.8

+ 13—28/ + 29 - -8

- 3 . 1 / + 5.5

13.8/7.3

+ 19—49/ + 20-— 10

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

124 HYPERTENSION VOL 5, No 1, JANUARY-FEBRUARY 1983

A AU5C-INTRA-ART. BP( xiSDiRANGE)mmHg 5 CE S DZ

• 30i

• 10

0

-10-

-20

-30

-40

-50CUFFAVERAGEAUSC.BP

v:;X;>X

ijiYi'm

HYPERTENSIVn=59

12 x 35cm1740/108-4mn

'E

iHg

:::•:•:•:•::::

OBESEn = 52

15x43154-9/92-3 mmHg

FIGURE 1. Difference between auscultatory and intraarterialarm blood pressure in 59 hypertensive subjects with arm cir-cumferences less than 35 cm and 52 obese subjects with armcircumference more than 35 cm. (S = systolic BP; D V =diastolic BP; auscultatory BP measured at Phase V).

Correlation with Height of Blood PressureIn both groups a negative correlation was found

between the auscultatory-intraarterial systolic BP andthe height of systolic arm BP (fig. 2), i. e., the measureartifact increased with increasing pressure. No signifi-cant correlation was observed between the measureartifact and the height of diastolic BP (fig. 2). Thehypertensives were divided into three groups accord-ing to the height of the intraarterial SBP (table 3). In allgroups, auscultatory DBP was about 10 mm Hg abovethe intraarterial DBP and the scatter of the readingswas nearly equal, although the smallest range of DBPreadings was found in the group with lowest SBP.

Correlation to Arm CircumferenceIn both groups, a slightly positive, but statistically

insignificant, correlation was observed between armcircumference and the measure artifact of both SBPand DBP (fig. 3).

A AUSC -INTRA-ARTSYST BP

mmHg

•30

.20

HYPERTENSIVE

INTRA-ARTSYST BP

A AUSC-INTRA-ARTDIAST. BP

mmHg HYPERTENSIVE

A AUSC -INTRA-ARTSYST. BP

mmHg

INTRAARTSYST BP

• 200 . 250 mmHg

r--041

A AUSC -INTRA-ART.DIAST. BP

mmHg

ARM006 CIRCUM-

FERENCE

FIGURE 2. The measure artifact (i.e., auscultatory-intraarterial blood pressure) in relation to level of blood pressure in 59hypertensive subjects (left) and 52 obese subjects (right).

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

AUSCULTATORY BLOOD PRESSUREJNielsen et al. 125

TABLE 3. Difference between Auscultatory and Intraarterial BPin 59 Hypertensive Subjects Divided into Three Groups Accordingto Intraarterial SBP

TABLE 4. Difference between Auscultatory and Intraarterial BPin 59 Hypertensive Subjects Divided into Three Groups Accordingto Age

IntraarterialSBP

(mm Hg)

55200 (n = 15)

Mean

SD

Range

160-l99(n = 26)

Mean

SD

Range

<160 (n = 18)

Mean

SD

Range

AAuscultatory/Intraarterial BP

Systolic(mm Hg)

- 8 . 7

9.2

- 2 8 / + 5

- 6 . 3

9.5

- 2 0 / + 13

-3 .1

7.4

- 20/ + 9

Diastolic(Phase V)(mm Hg)

+ 9.3

7.1

- 6/ + 23

+ 11.7

7.9

- 8/ + 29

+ 10.7

4.8

+ 4/ + 20

Age group(yrs)

S60 (n = 11)

Mean

SD

Range

50-59 (n = 32)

Mean

SD

Range

<50 (n = 17)

Mean

SD

Range

AAuscultatory/Intraarterial BP

Systolic(mm Hg)

- 5 . 6

11.2

-28 /+12

-6 .2

6.9

-23/+ 11

- 7 0

10.0

- 20/ + 9

Diastolic(Phase V)(mm Hg)

+ 11.3

7.5

-27 4-23

+ 10.1

5.8

- 6 / + 29

+ 9.2

10.9

- 2 0 / + 28

A AUSC-INTRA-ARTSYST BP

mmHg•30-

HYPERTENSIVE

ARMCIRCUM-FERENCE

A AUSC-INTRA-ARTDIAST BP

mm HiHYPERTENSIVE

r=013ARMCIRCUM-FERENCE

A AUSC -INTRA-ARTSYST BP

mrnHg

•30-1

•20

• 10

0-

-10

-20

OBESE

ARMCIRCUM-FERENCE

A AUSC -INTRA-ARTDIAST BP

mmHg•30

•20

• 10-1

0

-20

50

OBESE

INTRA-ARTDIAST BP

. . j=-0 29150 mmHg

FIGURE 3. The measure artifact (i.e., auscultatory-intraarterial blood pressure) in relation to arm circumference in 59 hypertensivesubjects (left) and 52 obese subjects (right).

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

126 HYPERTENSION VOL 5, No 1, JANUARY-FEBRUARY 1983

Correlation to AgeNo correlation between age and the measure artifact

of either SBP or DBP could be demonstrated in thehypertensive or obese group. The hypertensives weredivided according to age into three groups. As seen intable 4, there was no substantial difference between themeasure artifact of the groups but, it should be men-tioned that most of the patients were between 50 and 59years old, and only 11 were 60 years or older.

Correlation to Antihypertensive MedicationIn the hypertensive group, 56 of the 59 patients were

on antihypertensive medication at the time of investi-gation. The medication varied considerably, however,and it was not possible to collect pure groups on differ-ent medications.

DiscussionThe present study showed, on the average, good

agreement between auscultatory and intraarterial BPmeasurements, among the hypertensive subjects andobese subjects; auscultatory SBP was a few mm Hgbelow intraarterial SBP, while auscultatory DBPPhase V was on the average a few mm Hg above theintraarterial DBP. This corresponds to previous studiesof several authors (table 5). We have not includedmeasurements of DBP Phase IV as we found it wellestablished from earlier investigations7" that DBPPhase IV gave DBP readings too high compared tointraarterial values. As mentioned in the introduction,in the previous studies other than that of Donde et al. ,3

only a few of the patients were hypertensive. It isinteresting that the SBP measure artifact increased

TABLE 5. Age and Patient Categories in Earlier Comparisons of Auscultatory and Intraarterial Arm Blood Pressure

Authors

Ragan & Bordley(1941) (ref. 1)

Roberts & al.(1953) (ref. 2)

Henschel & al.(1954) (ref. 3)

Van Bergen & al.(1954) (ref. 4)

Godden & al.(1955) (ref.* 5)

lmhof & Hurlimann(1958) (ref. 6)

Karvonen & al.(1964) (ref. 7)

Holland & Hummerfelt(1964) (ref. 8)

Simpson & al.(1965) (ref. 9)

King (1967) (ref. 10)

Raftery & Ward(1968) (ref. 11)

Forsberg & al.(1970) (ref. 12)

Donde & al.(1974) (ref. 13)

No. ofsubjects

40

47

11

70

35

40

53

47

24

25

50

52

104

Age(yrs)

adults

>70

21-28

3-82

—

19-80

<20-61

10-69

23-66

18--44

18-83

Patientsinvestigated

From syphilisor hypertension clinic

Volunteers fromthe med wardsmales

Young normotensivemen

Surgery patientsin general anesthesia

Healthy youngadults

Healthy adults

Postoperativeinvest, of differentsurgical patients

Different patientsand staff members

Different patientsand staff members

Normotensiveyoung men

Pregnant, normo-tensive women

Differentpatients

Normotensive andhypertensiveadults

Numbertreated oruntreated

hypertensive

12

3

None

"Many of the pa-tients were hyper-tensive"

None

about 10

SBP>160:l8DBP>100:10

SBP>160:18DBP> 100:9

SBP>160:4DBP>100:l

cuff 13x26None

cuff 13 x 42

None

18 hypertensive(12 nonobese,6 obese)

>160 and/or>1OO:55Overweight>20%:65

Auscultatory/Interarterial BPAverage difference and range (or SD)

SBP(mm Hg)

- 0 . 4- 2 1 / + 40

- 1 2 . 3 S D = I 4

- 4 2 / + 30

- 4S D 8 1

Mean, SD, orarticle andfigures.

- 9 . 7- 3 0 / + 1 8

- 0 . 4- 1 3 / + 10

+ 0.5SD 12.3

-24 .5- 4 7 / + 7

- 3 . 7SD5.7

r -4.4\ -30/ + 40

\-20/+10- 5 . 4

- 2 9 / + 1 8

+ 4SD 12.1

-12 .0- 7 0 / + 48

DBP(Phase IV)(mm Hg)

L2+ 4.4(SD8.

- 1 8 / + 23

DBP(Phase V)(mm Hg)

+ 8.4-11 + 30

- 2 4*7) (SDII .O)*

- 3 6 / + 1 9

- 5SD5.8

range are not given in thecannot be extracted from the

+ 7 3- 20/ + 31

+ 17.7SD 15.1

- 5 . 3- 3 7 / + 32

+ 11.1- 7 / + 29

+ 13.0- 1 4 / + 36

+ 10.9- 4 / + 29+ 7.6

SD 14.4

-13.1- 4 2 / + 2

+ 1.7SD 8 1+ 12.6

- l / + 30t+ 12.1

- l / + 25t

+ 6.6- 1 3 / + 26+ 15SD9.7

*Six patients with DBP (Phase V) = 0 are not included in the calculation.tRange read from figures in the article.

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

AUSCULTATORY BLOOD PRESSURE/Nielsen et al. 127

with increasing BP, a finding also observed by otherauthors.6'8 "•l3 This seems to be explained not by theinability to record the first audible Korotkoff sound,but by the increasing "critical closing pressure" withthe increasing level of blood pressure.16

The divergence from the study published by Hollandand Humerfelt8 is hard to explain, as contrary to allother studies, these authors found intraarterial BP val-ues much higher than both systolic and diastolic aus-cultatory BP, but could not explain this divergency.

In all previous studies, as in ours, considerable in-terindividual differences were observed with a widescatter of the measure artifact. It is important to stressthat the measure artifact cannot be predicted in thesingle patient from age, height of blood pressure, orarm circumference.

The occluding cuffs used by us should be discussedfurther. For the hypertensive subjects with an arm cir-cumference less than 35 cm, the balloon used was 12cm in width and 35 cm in length, in accordance withthe previous recommendation from American HeartAssociation17 i.e., the width of the cuff was equal to120% of the diameter of the extremity. In 1980 theAHA Committee still recommended18 a bladder lengthtwice the width of the cuff. Karvonen et al.7 and Simp-son et al.9 argued earlier that interindividual differ-ences seemed to be reduced if a 35-cm long cuff wasused in normal adults. The present study showed that,even with a 35-cm long cuff, the interindividual vari-ation is still considerable.

For the obese subjects we used a 15 x 43 cm cuff. Itis important to stress that, if a 12-cm cuff is used forobese subjects, over estimation of arm blood pressure(cuff hypertension) may occur.5 Our study shows asimilar average difference and interindividual scatterin the hypertensive group, with a normal dimension ofthe upper arm, compared with the data for the obesegroup where a wider cuff was used. We therefore rec-ommend a 15-cm cuff for obese subjects with an armcircumference exceeding 35 cm. The last AHA recom-mendation18 was for a 17-cm cuff in large adults witharm circumferences between 32 and 42 cm, and even a20-cm (thigh) cuff in the extreme when the circumfer-ence is over 42 cm. We tried to use wide cuffs in theobese group acording to the 120% rule, but had to giveup as it was nearly impossible to place such wide cuffsaround the upper arm because of the conic shape andthe often short length of the upper arm. We find thecommercially available 15 X 43 cm cuff most suitablein this group where hypertension is often suspected.

From the present results it might seem desirable tocompare auscultatory and intraarterial BP measure-ments in all the hypertensive subjects. However, thecomparison is time-consuming and may be painful for

some patients, even if local anesthesia is used. Further-more, technical equipment and technicians are needed.Therefore it cannot be recommended that evaluation ofthe measure artifact be performed for all patients. Weare now using the measurements from subjects whosehypertension is poorly controlled, in order to establishwhether the measure artifact exceeds the average find-ings of the present investigation. If a gross overestima-tion of the intraarterial DBP results, we recommendtaking this finding into account when antihypertensivemedication is titrated.

References1. Ragan C, Bordley J The accuracy of clinical measurements of

arterial blood pressure. Bull Johns Hopkins Hosp 69: 504, 19412. Roberts LN, Smiley JR, Manning GW. A comparison of direct and

indirect blood-pressure determinations Circulation 8: 232, 19533 Henschel A, de la Vega F, Taylor HL: Simultaneous direct and

indirect blood pressure measurements in man at rest and work. JAppl Physiol 6: 506, 1954

4. Van Bergen FH, Weatherhead DS, Treloar AE, Dobkin AB, Buck-ley JJ: Comparison of indirect and direct methods of measuringarterial blood pressure. Circulation 10: 481, 1954

5. Godden JO, Roth GM, Hines EA: The changes in the intraarterialpressure during immersion of the hand in ice-cold water. Circula-tion 12: 963, 1955

6. Imhof P, Hurlimann A. Ergebnisse aus vergleichender indirekteund direkter blutdruckmessung Cardiologia 33: 2, 1958

7. Karvonen MJ, Telivuo LJ, JSrvinen EJK: Sphygmomanometercuff size and the accuracy of indirect measurement of blood pres-sure Am J Cardiol 13: 688, 1964

8 Holland WW, Humerefelt S: Measurement of blood-pressure:comparison of intra-arterial and cuff values Br Med J 2: 1241,1964

9 Simpson JA, JamiesonG, DickhausDW, GroverRF: Effect of sizeof cuff bladder on accuracy of measurement of indirect bloodpressure. Am Heart J 70: 208, 1965

10. King GE: Errors in clinical measurement of blood pressure inobesity Clin Sci 32: 223, 1967

11. Raftery EB, Ward AP. The indirect method of recording bloodpressure Cardiovasc Res 2: 210, 1968

12. ForsbergSA, De Guzman M, Berlind D: Validity of blood pressuremeasurement with cuff in the arm and forearm. Acta Med Scand188: 389, 1970

13. Donde R, Rab0l A, Rahbek M, Justesen O: Sammenligning mcl-lem indirekte og direkte blodtryksmalinger. Ugeskr Ljeger 136:1431, 1974

14 Sjukvardens och socialvardens planerings- og rationalisenngs in-stitut (SPRI). Specifikation 44301. Stockholm, 1970

15 Nielsen PE, Janniche H: The accuracy of auscultatory measure-ment of arm blood pressure in very obese subjects. Acta Med Scand195: 403, 1974

16. Burton AC: Physical principles of circulatory phenomena: Thephysical equilibrium of the heart and blood vessels. In Handbookof Physiology, edited by Hamilton WF. Washington DC: Ameri-can Physiological Society, 1962

17. American Heart Association: Recommendations for human bloodpressure determinations by sphygmomanometers. Circulation 36:980, 1967

18. American Heart Association: Recommendations for human bloodpressure determinations by sphygmomanometers. Hypertension 3:509A, 1981

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from

P E Nielsen, B Larsen, P Holstein and H L PoulsenAccuracy of auscultatory blood pressure measurements in hypertensive and obese subjects.

Print ISSN: 0194-911X. Online ISSN: 1524-4563 Copyright © 1983 American Heart Association, Inc. All rights reserved.

is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231Hypertension doi: 10.1161/01.HYP.5.1.122

1983;5:122-127Hypertension. 

http://hyper.ahajournals.org/content/5/1/122World Wide Web at:

The online version of this article, along with updated information and services, is located on the

  http://hyper.ahajournals.org//subscriptions/

is online at: Hypertension Information about subscribing to Subscriptions: 

http://www.lww.com/reprints Information about reprints can be found online at: Reprints:

  document. Permissions and Rights Question and Answer process is available in the

Request Permissions in the middle column of the Web page under Services. Further information about thisOffice. Once the online version of the published article for which permission is being requested is located, click

can be obtained via RightsLink, a service of the Copyright Clearance Center, not the EditorialHypertension Requests for permissions to reproduce figures, tables, or portions of articles originally published inPermissions:

by guest on July 6, 2018http://hyper.ahajournals.org/

Dow

nloaded from