A Study of Duroziez's Murmur of AorticInsufficiency in Man Utilizing an

Electromagnetic FlowmeterBy JOHN D. FoLTs, B.S.E.E., WILLIAM P. YOUNG, M.D., AND

GEORGE G. ROWE, M.D.

SUMMARYFemoral arterial blood flow was recorded with an electromagnetic flowmeter at the

time of open heart surgery on subjects with and without aortic insufficiency. The recordsdemonstrated that subjects with severe aortic insufficiency and Duroziez's murmur hada large amount of retrograde flow in the femoral artery. Those subjects without signifi-cant aortic insufficiency and no Duroziez's murmur had little or no backflow. Whenonly a moderate amount of aortic insufficiency was present, the correlation was lesssatisfactory. In some subjects who had femoral backflow, a second recording was madefrom the femoral artery after the aortic valve had been replaced, and in these instancesthere was no longer any measurable backfiow. Postoperatively these patients did nothave Duroziez's murmur.

It is concluded that Duroziez's crural murmur in subjects with aortic insufficiency isassociated with retrograde diastolic femoral arterial blood flow.

Additional Indexing Words:Femoral artery flow Openheart surgery Hemodynamics Physical diagnosis

SINCE THE MIDDLE of the nineteenthcentury, it has been postulated that the

double crural murmur of Duroziez associatedwith aortic insufficiency is produced by for-ward flow during systole and retrograde flowduring diastole.' 2 While this would seem tobe a reasonable explanation, a considerableamount of investigation has been undertakenand conclusions have been drawn which bothsupport3 4 and deny5 6 this contention. Arecent report presented cineangiographic evi-dence that contrast material infused at a con-stant rate into the femoral artery was sweptsharply backward during diastole in subjectswith Duroziez's murmur.7 Most of the pre-vious attempts to investigate this condition

From the Departments of Medicine and Surgery,University of Wisconsin Medical School, 1300 Uni-versity Avenue, Madison, Wisconsin.

This work was supported in part by Grant HE-07754 from the U. S. Public Health Service, Na-tional Institutes of Health.

426

have been indirect, inferential, and somewhatsubjective.

It would seem that a device such as anelectromagnetic flowmeter, which records for-ward flow as a positive deflection and retro-grade flow as a negative deflection, shouldbe ideal to measure the flow direction ina subject with Duroziez's murmur, and thusto establish the presence or absence of back-flow. While some investigators are not willingto accept the quantitative nature of datafrom electromagnetic flowmeters, most willaccept their qualitative recording of forwardand backward flow. Furthermore, there isconsiderable precedent for the present tech-nique since other investigators have reportedresults of flow studied acutely during surgicalprocedures on the carotid,8 hepatic,9 pulmo-nary,10 femoral,"l popliteal,12 and other ar-teries.13

MethodsFor this study a Medicon K2000 electromag-

netic flowmeter was used. The electrical outputCirculation, Volume XXXVIII, August 1968

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DUROZIEZ'S MURMUR

/

//0

a/

pp

0/~~~~

S/~~~~~I?/~~~~~

I I I200 400 600 800

MILLILITERS / MINUTE

1000 1200

Figure 1

Calibration curve showing blood flow plotted against output of the flowmeter.

of the flowmeter was recorded on a Sanbornmodel 296 two-channel portable recorder. Elec-tromagnetic flowmeter probes were constructedin 1-mm increments for the range from 5 to 10mm. Each probe was calibrated prior to use,

using a segment of dog abdominal aorta ofappropriate size. Blood was passed through thevessel at various rates, into a graduated cylinder,and the corresponding deflection recorded. Theblood flow in milliliters per minute was plottedagainst the output of the flowmeter. A calibra-tion curve, as shown in figure 1, was preparedfor each probe.

The probe was applied to the femoral arteryafter it had been exposed but prior to its use

for the arterial inflow during cardiopulmonarybypass. Zero flow was recorded by temporarilyclamping the vessel. The forward flow of bloodinto the extremity was represented in the pul-satile flow profile as the area under the curve

and above the zero line, whereas backflow was

Circulation, Volume XXXVIII, August 1968

indicated by the curve below the zero line.Since the response of the flowmeter is linear,the ratio of the areas below to those above thezero line was converted simply into the percent-age of backflow.A variety of subjects were studied, but for

purposes of this communication they were di-vided into those with and without aortic insuffi-ciency. The criteria for the amount of aorticinsufficiency were those of cardiac catheterizationand surgical exploration. At catheterization aorticinsufficiency was estimated by injecting indocy-anine-green dye into the aortic root and with-drawing blood continuously through equisensitivecuvette densitometers from the left ventricle andthe femoral artery. The estimate of insufficiencyrelated the amount of dye which appeared inthe left ventricle to that which appeared in thefemoral artery. Aortic insufficiency was also esti-mated from cineangiocardiograms taken duringaortic root injection. Direct observation of aorticinsufficiency was made at operation when, during

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Figure 2Example of phasic flow pattern in a case of aortic stenosis without significant aortic insufficiency.

Figure 3Flow pattern in severe aortic stenosis and moderate aortic insufficiency.

bypass, the left ventricle was opened. Utilizingthe composite of information obtained by theindicator-dilution curves, cineangiocardiograms,and observations made at operation, the aorticinsufficiency was categorized as none, moderate,or severe. The group with aortic insufficiencywas further divided into those who exhibitedDuroziez's murmur and those who did not. The

criteria for Duroziez' murmur were strictly clin-ical. It was recorded as present or absent afterauscultation for the diastolic murmur duringvarying degrees of compression over the femoralartery.

Cardiac index was determined at catheteriza-tion by the Fick principle. Expired air wasanalyzed for oxygen and carbon dioxide by the

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OS 30Js. 155h.. Op 1--66Dx: Severe Al, VSD with teft to right Shunt (Dutrozlez's numurl)L. Syst. FlcIow 4.78 L. /in 2L. Cardiac Index 2.:2 L. Imnin.'M

BEFORE

Figure 4Flow pattern in very severe aortic insufficiency and ventricular septal defect.

Scholander apparatus, and blood gases were de-termined by the Van Slyke-Neill method.

ResultsAn example of the phasic flow pattern of

a subject with aortic stenosis and no signifi-cant insufficiency is shown in figure 2. As can

be seen there is considerable flow into the ex-

tremity and very little, if any, backflow. Themagnitude of forward flow recorded immedi-ately after removal from the cardiopulmonarybypass is greater than one would expect fora lower limb under normal circumstances.This is probably due to reactive hyperemiasecondary to ischemia in the extremity duringthe bypass. A subject with severe aortic steno-sis and moderate aortic insufficiency producedthe flow pattern presented in figure 3. Thissubject has a small amount of femoral back-flow but apparently not enough to producean audible Duroziez's murmur. Figure 4 pre-

sents the flow pattern of a subject with very

severe aortic insufficiency and a ventricularseptal defect. This individual had a veryloud Duroziez's murmur and showed a con-

siderable amount of retrograde femoral flow.Indeed the integrated area below zero exceedsthat above and must be attributed to instru-

Circulation, Volume XXXVIII, August 1968

mental error. Clearly more blood cannot flowout of the femoral artery during diastolethan enters during systole unless this occurs

only transiently. The second record in figure4 was taken 45 minutes after discontinuingcardiopulmonary bypass with a normally func-tioning aortic valve. The flow into the femoralartery is in a normal range and no backflowis evident.

Further results are summarized in table1. As can be seen on all ocasions but one,

when Duroziez's murmur was observed, a

significant amount of femoral arterial back-flow was measured at operation. In the one

discrepant case Duroziez's murmur was con-

sidered to be slight. Two patients, O.H. andP.M., who had moderate aortic insufficiencyshowed some femoral arterial backflow, butdid not exhibit Duroziez's murmur. It is tobe expected that subjects with moderateaortic insufficiency and a small amount ofbackflow may well have a borderline con-

dition that may not produce an audiblecrural murmur.

DiscussionSome observers think that an electromag-

netic flowmeter probe should be left in place

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Table 1Duroziez's Murmtur of Aortic Insufficiency

Subject Diagnosis

P.C. VSDG.P. ASH.D. Severe MS,

moderate AIJ.P. Moderate Al,

ASC.M. MS, MI, AlO.H. Severe AS,

moderate AIP.M. Mild MI,

moderate TI, AIR.B. Mild MI,

severe AID.S. Severe AID.S. Coare. aorta,*

severe AIW.J. Severe AID.S. Severe AI,

VSD

Duroziez's murmurBefore Aftervalve valverepair repair

No NoNo NoNo No

No

SlightNo

No

Yes

YesYes

YesYes

Cardiacindex

(L/min/m2)

2.33.82.9

Meanfemoralflow

(ml/ min)

300380320

No 3.5 340

NoNo

Backflowbeforevalve

repair (%)

000

0

370 03.1 350 9

No 2.5 320 15

No 3.9 310 23

NoNo

NoNo

3.4 220 353.0 270 48

2.8 180 963.0 50 119t

*Coarctation of the aorta had been repabicuspid aortic valve became incompetent.

tSee text for discussion of this figure.

for several days to ensure complete weldingof the probe to the arterial surface beforetruly objective measurements of flow can bemade. Whereas this is no doubt ideal, it isnot practicable for the present type of study,and in our experience if a good fit is obtainedand movement of the probe on the vessel isminimal, a reasonably accurate measurementcan be achieved. Additional features of thepresent probe, such as graphite coating andslightly elevated contact electrodes, may en-hance the accuracy of the acute measurement,for clearly there was some error as indicatedin figure 4 and in table 1.In two recent studies human ascending

aortic blood flow was measured with anelectromagnetic flowmeter.14' 15 The investi-gators observed that during an open chestoperation a normal aortic valve preventeddiastolic backflow into the left ventricle asdid a prosthetic valve.'4 15 However, in sub-jects with aortic insufficiency as much as43%14 to 75%15 of the left ventricular strokevolume regurgitated into the left ventricle

aired at a previous operation. Subsequently the

through the incompetent aortic valve. It seemsinevitable that if 75% of the blood ejectedinto the aorta reverses its direction and re-enters the ventricle during diastole, someof the blood in the more distal arterial treewould also have to reverse its direction offlow. This is consistent with the present ob-servations that in some subjects with severeaortic insufficiency large amounts of femoralarterial diastolic backflow occurred. In ad-dition, the present results demonstrate that,after the valve was repaired, backflow at thelevel of the femoral artery was reduced es-sentially to zero, as has been reported in theascending aorta.'14 15

It is believed that the overall correlationpresented in this study is reasonably good;that is, a subject with severe aortic insuffi-ciency and a readily audible Duroziez'scrural murmur has considerable diastolicbackflow in the femoral artery. A patient witha moderate amount of aortic insufficiency andwith an equivocal Duroziez's murmur may ormay not show femoral backflow at operation;

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and a patient clearly without aortic insufficien-cy and without Duroziez's murmur shows nosignificant backflow. It is not surprising thatthere are some discrepancies in the middleground. Duroziez's murmur is not easilyelicited in all subjects, particularly in thosewho are overweight and in whom retrogradeflow is small. The degree of compressionrequired to elicit the murmur is critical andmay be difficult to achieve. Furthermore, itmay be possible to confuse the murmur cre-ated by blood passing out of the extremitythrough the vein with that caused by bloodpassing out of the extremity in the artery.The murmur attributed to venous outflow isthought to be a continuous rumbling mur-mur,2 but only its diastolic portion may beheard if the degree of compression in thefemoral artery is sufficient to produce a loudsystolic murmur overwhelming the lowerpitched and softer continuous component. Wehave no objective evidence that this rumblingmurmur is produced in the venous system, butsuch a murmur was described by Duroziez2and has long been presumed to be venous inorigin. Finally, backflow from a vascular bedas large as that of the femoral artery mustdepend on resistance to runoff through itsperiphery as opposed to diastolic resistancein the more proximal vascular beds. Thus if,for example, the femoral resistance is highowing to chilling the extremity and the vis-ceral resistance is low, it would be expectedthat the elastic femoral vascular bed wouldgive up blood to the lower resistance systemduring diastole. This was demonstrated tooccur in a previous study of Duroziez's mur-mur7 and may explain some of the discrepan-cies in the present study.

References1. MAJOR, R. H.: Classic Descriptions of Disease:

With Biographical Descriptions of the Authors,ed. 3. Springfield, Illinois, Charles C Thomas,Publisher, 1959.

2. DUROZIEZ, P.: Du double souffle intermittentcrural, comme signe de l'insuffisance aortique.Arch Gen Med 107: 417, 588, 1861. Citedfrom translation by E. Hausner. In Willius,

F. A., and Keys, T. E.: Cardiac Classics. St.Louis, C. V. Mosby Co., 1941.

3. BLUMGART, H. L., AND ERNSTENE, A. C.: Twomechanisms in production of Duroziez's sign:Their diagnostic significance and clinical testfor differentiating between them. JAMA 100:173, 1933.

4. WARREN, S. REM, JR.: Sounds from the thorax:Acoustic principles. In Leopold, S. S.: Prin-ciples and Methods of Physical Diagnosis:Correlation of Physical Signs with Physiologicand Pathologic Changes in Disease. Phila-delphia, W. B. Saunders Co., 1952, p. 430.

5. RUSHMER, R. F.: Cardiovascular Dynamics, ed.2. Philadelphia, W. B. Saunders, Co., 1961,503 pp.

6. LUISADA, A. A.: On pathogenesis of signs ofTraube and Duroziez in aortic insufficiency:Graphic study. Amer Heart J 26: 721, 1943.

7. ROWE, G. G., AFONSO, S., CASTILLO, C. A., ANDMcKENNA, D. H.: Mechanism of the produc-tion of Duroziez's murmur. New Eng J Med272: 1207, 1965.

8. HARDESTY, W. H., ROBERTS, B., TOOLE, J. F.,AND ROYSTER, H. P.: Studies of carotid-arteryblood flow in man. New Eng J Med 263:944, 1960.

9. SCIIENK, W. G., JR., MCDONALD, J. C., Mc-DONALD, K., AND DRAPANAS, T.: Direct mea-surement of hepatic blood flow in surgicalpatients: With related observations on hepat-ic flow dynamics in experimental animals.Ann Surg 156: 463, 1962.

10. SCHENK, W. G., JR., MCDONALD, K. E., ANDKENNEDY, P. A.: Direct measurement of hu-man pulmonary hemodynamics during thora-cotomy. Ann Surg 157: 298, 1963.

11. DELIN, A., AND EKESTROM, S.: Evaluation ofreconstructive surgery for arterial stenosisfrom intraoperative determination of flow,pressure and resistance. Acta Chir Scand130: 35, 1965.

12. MANNICK, J. A., JACKSON, B. T., AND COFF-MAN, J. D.: Hemodynamics of arterial surgeryin atherosclerotic limbs. Surgery 60: 578,1966.

13. MORAN, J. M.: Current concepts: Blood flow-meters. New Eng J Med 276: 225, 1967.

14. SCHENK, W. G., AND ANDERSON, M. N.: Humanascending aortic blood flow measurements.Ann Surg 160: 366, 1964.

15. MORROW, A. G., BRAWLEY, R. K., AND BRAUN-WALD, E.: Effects of aortic regurgitation onleft ventricular performance: Direct determin-ations of aortic blood flow before and aftervalve replacement. Circulation 31 (suppl. I):1-80, 1965.

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JOHN D. FOLTS, WILLIAM P. YOUNG and GEORGE G. ROWEElectromagnetic Flowmeter

A Study of Duroziez's Murmur of Aortic Insufficiency in Man Utilizing an

Print ISSN: 0009-7322. Online ISSN: 1524-4539 Copyright © 1968 American Heart Association, Inc. All rights reserved.

is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231Circulation doi: 10.1161/01.CIR.38.2.426

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