Paradoxical precordial motion and wasted left ventricular work: The concept of cardiac dyssynergy

Paradoxical

precordial

motion

and wasted The concept

left ventricular work: of cardiac dyssynergy

Joh,c 0. Ltrngley, M.D.* ~llvclro Mtrrtinez, M.D.** Ali Fukhro, M.D.*** Peter Duvoisin, U.D.**** 1’. K. Harrison, U.D. Hivminghclnz, Alu.

I

n young persons with normal hearts the largest precordial deflections with the cardiac cycle are those due to change in volume, and thus are inward during systole and outward during diastole. As ejection begins, there is a brief outward recoil motion, largest at the apex. These several deflections, as well as certain other small systolic outward movements, have been described in detail in previous studies.‘-” The exaggerated abnormal systolic outward motions that occur in patients with ischemic heart disease”,” and in those with ventricular hypertrophy6 have been discussed in other communications from this laboratory. That a certain amount of cardiac work is wasted (i.e., not directly utilized during isovolumic contraction for elevation of pressure or subsequently for ejection) in producing these paradoxical movements is obvious. The crucial ques-

tion is: Ho\l- much? The studies on dogs l)y Tennant and IViggers,’ of I\lurray,8 and Tyson and associates,” which have been summarized elsewhere,lO suggest that this wastage is OQsignificant degree. The purpose of the present study is to attempt to answer the question in man. Subjects and methods The persons studied were the following: CL. Thirteen individuals with normal hearts, as judged by clinical and electrocardiographic criteria. Of these, 10 were 39 years old or less, and 3 were 40 years old or more. b. Fifteen patients with ischemic heart disease, as indicated either by typical angina1 pain or by myocardial infarction in the past, or by both. One of them had normal kinetocardiographic records, \I-hereas the others were selected because

From the Department of Medicine, Medical College of Alabama, Binningbarn, Ala. This work was supported in part by Grants No. 8MOl FR-32-03 and IIE 0.5080 from the Sational Institutes and by the Elesabeth and Barbara Ingalls Fund, the Callmun County IIeart Association. and Mr. Received for publication May 24, 1966. *Fellow of the Alabama Heart Association. **Trainee of the National llunrt Institute. ***Trainee of the United States Public Health Service. ****Fellow of the United States Public IIealth Service. 4ddresscorrespondence to Dr. Harrison. Department of Medicine, Medical College of Alabama. Birmingham

349

of Health, Hugh Kaul.

.Sla.. 3.5233.

they exhibited varying degrees of paradoxical outn-ard systolic motions (bulges). Rlultiple studies were made in 7 of these subjects. c. Thirteen patients \\-ith lesions (0 aortic valvular, 2 hypertensive, 2 congenital) that place an increased load on the left ventricle. Evidence of left ventricular h!.pertrophy; was seen in the EC(; in 10 of these subjects, and in the kinetocardiogram (paradoxical systolic motion in the region of the apex) in 11. Nine of these patients underwent cardiac catheterization on the day before or after the studies of precordial motion. d. Five subjects in \vhom the wasted \vork v\-as measured during aortic cathe-

terization, I\-rth ’ simultaneous determination of aortic pressure and left ventricular stroke volume by the method of Jones and associates.” J’atients with excessive loads on the right ventricle only were omitted from the study. The trpptrrr~t~s employed (Fig. 1) consists of a platform supported by four adjustal,lc “feet,” which can he fitted into the intercostal spaces overlying the area in the apical region which displayed the largest out\\-ard movement, as determined by previous KC<& taken from the several intercostal spaces (fourth to sixth) in the \-:( to IV5 vertical lines. The response of the recording apparatus (a Sanl)orn 4-channel

Fig. 1. .Section A: View of precordial weight carriage from above. ‘The apparatus is constructed of alunlilrun~ a~~tl consists of the following major parts: il, Adjustable “foot” designed to rest within the itltercostal space overcan be rotated to fit codiguration of lying the precordial “bulge.” B, Adjustment wing nut by which “foot” chest wall. C, Sleeve which allows extension of “foot” to further facilitate adjustment to tit configuration of chest wall. D, Platform atop which measured flat circular weights are sequentially placed. Section R: View of are shown, in order to avoid confusion. .l, precordial weight carriage from below. Only two of the four “feet” position in horizontal plane. Differences ill interspace width LVing nut which allows for adjustment of “foot” can thereby be compensated for. H, Same as B in Section _ I. C, .-ldjustment plus bolt, which allows same moveas .1 ill Section H. II, \\Yug Itut which discs sleeve (C in Scc,tioll .I) in position. E, ‘l‘rwk in nlents of “foot” which feet are attached to underside of platform (F ill Sectioll H), and through \vhich fc,et ca11 be moved ill horizontal plane. F, 17nderside of platfornl (see /I in Sect iw 1 ).

Ptrrcldoxiccll prccordicll

direct xvriter) to movement of a known distance was measured immediately prior to the study of each subject, so that at any given dial setting the millimeters of deflection of the trace could be converted into actual millimeters of movement of the chest wall. The sensitivity of the recorder remained essentially constant during the period (about 3 years) of the study. The procedure employed was as follows: The electrocardiogram (Leads I and II), the carotid pulse, and the movement of the platform were recorded simultaneously. The recumbent subject z&sumed a slightI> ol)lique position, with a pillow under the left axilla and shoulder. Weights were then added progressively to the platform until either (1) the weight X distance product became constant, decreased slightly, or showed little increase, or (2) the procedure became so painful that the subject was unwilling to tolerate additional weight. The latter situation was occasionally encountered. In the measurement of the records the level of the curve of platform movement at 0.04 second after the onset of the QRS was assumed to be the diastolic base line.6 The height and duration of the outward motion of the platform above this level were determined. Since the lveight on the platform was known, the work would then be calculated in gram-meters. The integral of work in gram-meter seconds was calculated bv measuring the area under the curve Lyith a planimeter. Typical findings for a normal person and for a patient with ;I moderately large IAge as progressively more weight was utilized are shon-n in Fig. 2. Crifiym qf method. The procedure is crude and indirect. It is uncomfortable for all subjects, painful for some, and intolerable for a few, especially those with snlall chests and narrolv intercostal spaces. We had assumed a priori that with added \veight there \vould IE a corresponding decline in excursion, and that the product, mass X distance, would remain relativeI> constant. The observation that such a m.ork plateau occurred onI>. with the heavier weights (and not at all in a fe\v sul)jertsj was initially surprising. The explanation is probably as follows: Some of the intercostal tissues are relntivel~~ rigid, and, ordinarily,

motion clnd wclsted L I’ work

3.51

much of the energy wasted by the heart in a systolic protrusion is presumably absorbed in stretching these structures. The motion that one feels (or records), thcrefore, represents onI)- the energy above and beI-ond such absorption. It is probable that one has to add enough weight to the chest to displace the relativelyrigid intercostal membrane slightly toward the thoraric cavity before the major fraction of the cardiac work involved in the bulge ljegins to be reflected at the surface. ,Although proof of this explanation is lacking, the observation that the work-x-distance plateau occurs at approximateI>. the same weight, regardless of the cardiac status (Fig. 2), is evidence that some structure other than the heart is responsible for the delayed work plateau. The configurations of the records in Fig. 2 are susceptible to multiple interpretations. Not only are there large early systolic upstrokes, indicating that the weight is \)eing lifted, but during the mid and late portions of systole there are large downstrokes, shon-ing that the lveight is descending. There can be no doubt that the early lift represents Iyork done on the weight By the heart. Is not the converse also true and does not the subsequent systolic descent of the weight represent work done orz the heart by the Lx-eight? If so, does not this represent an additional force favoring ejection and should not one, therefore, subtract the downstroke from the upstroke in measuring the wasted nork? Since this question is fundamental to the evaluation of the significance of our data, it ma!. I)e considered in some detail. The systolic descent of the \?-eight (Fig. 2) is ctbviousl>~ caused immediately l)>. inboard motion of the intercostal spaces. This could conceivat)l\; be due to several causes: (1) an actual indentation or compression of the left ventricular \\all, with displacement of blood; (7) a displacement of the entire heart away- from the weight; (3) displacement of a portion of the left lung; (‘4) compression of the adjacent portion of the left lung, \\.ith displacement of a sniall amount of air. Of the various substances (solids, liquids, and gases) and tissues (heart, l)lcod, and lung) that might l)e displaced, those nith the lonmt specific gravit!. (air and lung) offer the least re-

3.52

Langley, Mu&w,

Fcrkhro, Duvoisin, cud Harrison

.h. fgcsort .r. March, 196:

Fig. 2. Effect on precordial movements of progressive loading of precordial platform. Paper speed 50 mm. per second. Two complexes are shown beginning and ending with the P wave. The dotted lines Q, CU, and CIN refer, respectively, to the onset of the QRS, the start of the carotid upstroke, and the carotid incisural notch. The initial weight (B) caused a pronounced increase in the degree of systolic outward motion (upstroke) in both subjects. This is possibly to be ascribed to partial counterbalance of the stiffness of the intercostal membranes (see text). As additional weight was added (C), the systolic outward excursion again increased in both subjects, in Subject II because the sensitivity of the recording apparatus had been reduced. Thus, the mass X distance lifted was much greater for both subjects in C than in B. But when still more weight was added (D), the magnitude of the systolic outward movement decreased slightly. Thus, in both subjects the product, mass X distance, was about the same in D and in C. But because of the reduced recording sensitivity the actual distance that the same weight was lifted (wasted work) was about three times as great in the patient as in the normal subject.

sistance to such displacement. It is probable, therefore, that the correct explanation is one of the last two or a combination of Furthermore, the descent of the them. weight in late systole could facilitate ejection and thereby reduce wasted work on!!,

if the first case one chest wall in stroke changes. indicated

possibility were true. But in that would expect the weight on the to be associated with an increase vol~l~ne or other henlodynamic That these \\-ere not found is belo\\-.

I’trrcldoxictll

This discussion refers only to the left ventricle and to records from the region of the apex. Traces from the right parasternal area, where there is little or no lung anterior to the heart, may quite possibly be inlluenced by a direct effect of the weight in compressing the right ventricle. That is one of the reasons that this report is confined to patients with ischemic heart disease or left ventricular loads and to records secured from the region of the apex. One may summarize these several considerations by saying that there is strong, although indirect, evidence for the view that the lift of the weight as herein measured does represent a crude reflection of the xvasted work of the left ventricle. Because of the large amount of intervening lung, paradoxical motions cannot be recorded from the posterolateral portions of the left ventricle. Downward bulge of the diaphragmatic surface of the left ventricle likewise cannot be registered satisfactorily. One is limited to studying abnormalities of the movements of the anterolateral and apical regions. This defect in the tnethod can only produce f(llse low values for wasted work. The same is true of those patients who do not tolerate sufficient weight to achieve a work plateau. In these, one can only say that the actual wasted work is at least as great as, and possibly greater than, the measured value. Hemodynumic effects of weight on chest. The possibility that the procedure itself may lead to artificially high values for wasted work cannot be excluded with certainty. But if this were the case, one ii-ould expect that simultaneous measurements of hemodynamic functions would probably display evidence of a consistent alteration in cardiac behavior during the application of the heavy weight. The results of nine comparisons in 5 subjects are shown in Table I. Constant changes did not occur in heart rate, stroke volume, cardiac output, or useful cardiac work. The central aortic blood pressure was sometimes unchanged but usually increased somewhat, presumably because of pain. There was no indication that the procedure reduced the useful (pressure X flow) work by diverting energy to the wasted (weight lifting) work. Although the possibility that the wasted work was itself increased by the

precordial

motion (1xd wasted LI’

work

?I5 3

procedure cannot be excluded with certainty, this seems to be improbable in view of the inconstant changes in pressure and flow, and in view of the probability, already mentioned, that the values obtained by the tnethod tend to be falsely low rather than high. In any case, since a given weight was raised a given distance during systole, there can be no doubt that at least that much work was expended under the conditions prevailing when the measurement was made. Nevertheless, the failure to observe consistent alterations in the useful (pressure X flow) work during the application of the weights to the chest does not preclude with certainty the possibility that the procedure may have, in some unknown manner, caused a momentary exaggeration of the wasted work, as ‘herein measured. But it is reasonable to believe that. the results of the hemodynatnic observations reduce the likelihood of such a possibility.. Results

The data concerning the work involved in outward systolic movements are shown in Figs. 3 and 4 and sutntnarized in Table II. The work related to atria1 contraction and to those small outward motions during ventricular systole which do not cause displacement above the diastolic base line are neglected. The chief cause of the Lvork wasted by the normal heart is the outnard motion of the recoil as ejection begins. The normal values ranged from 0.13 to 5.3 gram-meters per beat, the median being 2.5. The integrals of wasted stroke \vork for normal hearts varied between .07 and .37 gram-meter seconds, with a median of .23. The median normal values for wasted work per minute \vas 205 grammeters (range, 7.2 to 640), and the median for the integral was 21.6 gram-meter seconds per minute (range, 3.9 to 32.3). The values for the wasted stroke work in patients with ischemic heart disease were above the normal range in 18 of 23 measurements on patients with systolic bulges that could be felt or recorded. The only patient without such a bulge had values well within the normal range. The figures for the integral of stroke work displayed a similar trend, with an even greater difference from the normal subjects. Only three measurements were within the normal range,

1,~ assuming

41

ICI’.

*Calculated

35

H.hI.

Gigc)

31

j

1

J .‘I-.

.Yubjec-t

/

mmn

1

7’trble 1. Hemodynnnzic

ncrtic

systolic

L)iabetes,

Chest

normal

pain

pressure

wall

heart

to he diastulic

Aortic stenosis, aortic insufficient!.

Dinpnsis

effects of weight on chest

;

I

pressure PIUS

“‘?

142 166 144 130 150 160 186 134

0 0 22 i 0 II. 77 7 0 22.7 0

?~~s”“‘-re, 3

161 1.58

132 172 160

0 22.7 22 7

0 22.7

118 118 113 113 109 98

0 22 7 0 0 22 7 0

.V.Ystolir

prfssrrue

132 150

j

Central

0 22.7

on chest (kilos)

llyfiyhr

/

and

Ng)

sprcific

94 96

90 108 110 98 110 104 110 84

92 120 115

76 76 70 70 64 62

70 8-1

Diastolic

(mm.

aortir

gravity

I

/ per

rute

67 68 65 80 89 90

75 8.5

minuk

$tf hlnod

73 75

Ij: 91 99 77 88 68 86

130 133 133

! 1 Heart

84 69

75 67 52 52 58 60 74 5s

38 39 45

135 138 140 144 123 114

118 141

Stroke volume (ml.)

to be 1.055.

1

/

6.1 5.2

4.7 5.0 4.7 5.1 4.5 5.3 5.0 1.7

4.9 5.2 6.0

9.1 9.1 9.1 11.5 10.8 10.3

8.8 12.0

/ Cardiac output ’ per minute (liters) !

131 115

115 122 90 81 102 105 143 80

57 77 64

201 20.5 196 202 16.5 141

176 258

’ Per beat I, (Gnz .,.I Al )

--

Lsrfd

--

9.6 8.7

7.2 9 1 8.2 8.0 7.8 93 9.7 6.7

7.4 10.1 8.6

13.5 13.9 14.8 16.2 14.7 12.7

13.2 21.9

Per minute (zig.Al.)

work*

g :: ,G. 9

is

-; s .; S‘

2 aT

5 3 s-. ;f 6

3%

c&

?I 2

Ptrrrrdoxicc~l precordicll motion clnd wcrsfed I, 1’ work

0 Patient

Class I I and II

‘Median

LV

IA. Wasted work

40

stroke

L’ 1

0 Patient I mtvkdian

Class III and

355

Izz:

B. lnte

rat of wasted stro R e work IHD

IHD

..

5250

.oads

Normal

II-ID

L!

-aads

Fig. 3. Stroke work xasted in paradoxical motion. ‘-1, Despite the scatter, the trend is toward an increase in wasted work with progressive functional impairment. The median \-alue for the Class III and Class 11,’ patients is about four times the normal, and the highest values are nearly 20 times the normal median. Because of the wide scatter the average values are not calculated. A, The median values for the integral of wasted work, which may be considered to represent wasted effort (see text) are 6 to 9 times as great in the Class III and Class IV patients as in the normal subjects. The maximal values are almost 40 times as large. The reason for the greater increase in the integral, as compared to the work, is the longer duration of the systolic outward motion in the patients than in the normal subjects. The Class 1 and Class II patients are intermediate in all respects. The probable reason for the low values in a few of the patients with pronounced functional impairment is the inabilit) of the method to detect abnormal systolic motions of the posterior and inferior portions of the left ventricle. Systolic protrusion of such areas would tend, because of the change it1 shape, to increase the inzuzrd movement of the apical region and thus to produce falsely low measurements of \vastetl \vorl;.

whereas the majority of the values were 3 to 30 times the average normal. The wasted work per minute was within the normal range in eight and below the normal median in three of 24 measurements, but above the normal range in 16 instances. The highest value was about 1,400 per cent above the normal median. The differences in regard to the integral of the wasted work per minute \vere again still larger, the median and

the highest values being, respectivel)., about 400 and 3,100 per cent alcove the normal median. Despite the \vide individual variations, the trend of all of the values for \\asted work was ton-ax-d a higher level for the patients with larger degrees (Class 111 and Class 11.) of functional impairment, ilS compared to those Lvith less ((‘lass I and Class I I) impairment.

356

Langley,

Martinez,

4ooo

Fukhro,

A.Wasted per

Duvoisin,

work

minute

rind Ficlrrison

B.

lnteqral work

of per

wasted

id I

minute

I 3500 c W t2

-700s c7 I

t I

IHD

3000-

-6OO$

2500-

-500~

d

5 I 2 5 g

z

0

2000-

- 400%

ii 2

s l-

1500-

-3002 3

g I z ‘s; Q 3

tooo-

I Normal i+-

L -2000 -I Q

r

soo-

-toow

5 t-

Z

Fig. 4. Left ventricular work per minute wasted in paradoxical motions. ?Igain we have the wide scatter with some values that are probably falsely low (see legend for Fig. 3). Despite this, the median and highest values for wasted work per minute in the Class III and Class IV patients are about 5 and 1.5 times the median normal measurement. Again the differences in the integrals are still greater, the median and highest values being, respectively, 8 and 30 times the median normal. The Class I and Class II patients are intermediate.

The findings in the patients with left ventricular loads were essentially similar to those in the patients with ischemic heart disease. Again there was a wide scatter, but the trend was toward elevated values for wasted work per beat and per minute and for a somewhat greater increase, as compared to the normal values, in the integrals of these functions. Likewise, the median levels were higher in the subjects with the greater functional impairment. Comparisons of wasted work with useful work (assumed) are shown in Table 11 I. The median values for wasted work of Class III and Class IV patients are about 10 and 1.5 per cent per beat and per minute, respectively, of the useful work of the normal adult heart. But the highest values

for wasted work are almost one half that of the normal useful work and may equal or exceed the reduced useful work of the heart in severe failure. The explanation for the greater abnormality in the integral measurements than in the wasted work values lies in the increased duration of the systolic outward motion in the patients. Although in the strict physical sense the work (mass X distance) performed in “chinning” oneself on a horizontal bar is the same whether one holds the position for a second or a minute, any school boy is aware of the difference in the effort required. A distinction should be drawn between the ejection work and the useful work. The former can be calculated if one knows the left ventricular pressure and the total

stroke volume, which in a patient with aortic or mitral regurgitation is not the same as the nzeclsllred stroke volume. Thus, in such patients the useful work (mean aortic pressure X measured stroke volume) is less than the ejection work. Similarly, in a patient n-ith severe aortic stenosis the ejection work ma)- far exceed the useful work (‘l’al~le III, Subjects C.\;C’. and R4.T.) I)ecause of the pronounced pressure gradient. In those patients who were subjected to cardiac catheterization it was possible to compare the useful work of the left ventricle with the wasted \vork of the systolic Ijulge. Such comparisons are shown in Taljle III. It should be noted that there \vet-e 2 patients (J.G. and P.Q.) who had grossly increased stroke work (as compared to an average normal value of about 100 grammeters) but no evidence of impaired efficiency in terms of excessive work wasted by systolic protrusion of the prec-ordiutn. Both of these patients were asymptomatic. In the 3 Class III patients the wasted work of the left ventricle was a . .signlhcnnt fraction-one fourth to one third-&of its useful work. The inefficiency--as herein roughly measured in ternls of wasted work~~seems to parallel the clinical state more closely than the performance in terms of output or stroke work (Table II 1). Thus, each of the Class III patients had an increase in wasted work, but the reduction in output and in stroke \\-ork was inconstant. So data concerning the patients with ischemic heart disease are included in Table III because none of them was catheterized.

Discussion Before certain implications of the data are considered, the crudeness of the method should be re-emphasized. Aside from the possible sources of error that have already been cited under Critique qf method, the measurements were made in acute experiments and do not reflect such adaptations as might occur in the heart during a period of months or years. Furthermore, the procedure of placing weights over the precordiunt is highly artificial and represents a type of load that is different from any occurring during the natural history

of cardiac disease. Likewise, it is high11 improbable that the values for wasted work are quantitatively accurate. Reasons why the method, as herein employed, probably J-ields false low values have been cited but the degree of error remains unknown. In anJ7 case, the data indicate that in patients with pronounced functional impalrment the work wasted in outward motion of the apex is no less than one fourth to one third of the useful work (Table III) and may actually equal the useful work of a patient in severe heart failure (Table II). These findings are in rough accord with the observation of Tyson and associates” concerning the functional intpairment of dogs with paradoxical movements of artificial ventricular aneurysms. The observations are in keeping with the bedside observation of a general parallelism between the gravity of the clinical state and the size--l)oth in amplitude and area--of the palpable systolic outward motion. The analogy already cited to “chinning” a horizontal bar illustrates that, when the position is sustained, the effort expended may be much greater than the work done. Thus, the median values for wasted stroke work and wasted work per minute of the Class III and Class IV patients were four to six times as great as those of the health>subjects. Hut the medians for the WW~SS& effort, i.e., the integral of wasted work, were s‘;x to ten times as large as the normal. In extreme instances (Figs. 3 and 4), the wasted work was fifteen to twenty times the normal, and the wasted effort was twenty to forty times the median normal. The patients with slight or no functional impairment were intermediate in all rcspects. During the past two decades, studies of pressure and flow in man have been of tremendous diagnostic value and have also advanced our concepts concerning the precise hemodynamic distortions caused by various mechanical lesions. Cardiac catheterization, as usually carried out, provides importattt information about performrlnce, i.e., about what the heart does. Rut it tells us little about euficiency, i.e., about what the heart does not do and bon- it fails to do it. These statements are not made to belittle a valuable method, but only to emphasize

Langley,

358

Table

II.

Martinez,

Wasted

work:

Fokhro,

Duvoisin,

cLnd Htrrrison

qf jindings

S~mmnry

/ Stroke

work

(gram-meters) Group

.)‘ubgroup

! /

\Vasted

work

Normal

Left

Approximate useful (flow X pressure) worli*

Table

by

III.

/

~~~-~~~

5.3

Ischemic

*Calculated

~ Highest

heart

disease

ventrirular

loads

Classes

I and II

Classes

III

Classes

I and

Classes

I I I and I\’

and

IV II

.13

2.5

15 8

1 .3

6.5

.z 8 .3

6.3

9.5

11.2

2.5

7 .o

44.5

3 .3

10.5

Normal Severe

assuming

Wasted

stroke

work

100 heart

volumes

40

failure

of 75 and

nnd useful

30 ml.. heart

work

rates

of i5 and

in p(ltients

110, duration

with

of ejection

left ventricular

-

of .28 and

.18 second.

respec

lauds

I

Subject

:4ge (Y. 1

Sex

II iag-

Class

7ZOSiS

Heart rate

Stroke volume (ml.1

Mean LV and aortic systolic pressure (mm. Hg)

31 21 18

M M M

I I I

66 71 80

82 93 138

P.Q.

19

F

I

78

75

J.D.

17

M

II

87

97

H.T. C.\V.

42 28

M M

II III

70 76

81 78

M.7‘.

39

1;

111

82

52

E.G.

24

M

III

80

5.5

because arteriosus.

the regurgitant dl: .4ortic

~

Wasted stvokc work (II’.SIr’)

Ejection

Useful ( USIT’)

Granzmeters

Jvsrr’ lJ.SMT ~ ( ‘Jk)

121 * 211

121 >117 170

4.3 11.3 4.7

3 5 97 2.8

165

84

1.0

4 8

125

96

9.5

9.9

* 268

> 144 90

14.6 21.8

10.1 21.2

167

59

17.R

29.3

*

> 143

-44.5

31.1

-

M.C. D.L. J.G.

*Cannot be calculated PII.4: Patent ductus

Woke work (gram-meters)

flow is unknown. insufficiency. -1s: Aortic

that it, like every other procedure, has its limitations. These considerations point to the conclusion that some of the prevailing concepts of ventricular behavior are based on oversimplifications. Thus, the idea that at an\.

10.1 88 107 86 154 78 90 69 121 240 81 224 79 188

stenosis.

given moment a Starling (function) curve of a ventricle reflects the state of all of the fibers of that ventricle is incompatible with the condition of a chamber xvhich has not only healthy Ijut also infarcted and intermediate (ischemic) areas, each of \vhich

Paradoxical

Integral of stroke work (gram-meter seconds) ____I_--

I___

Highest

Lowest

.37

.07

‘1 -.- 7

.16

8.1

.26

2 1

.31

75

.22

Median

Highest

23

640

.65 1.1 .60 1.9

V.ork per minute (gram-meters) ____-__-.I Lowest / Median

and

for severe

heart

Intryml of work per minute (gram-meter seconds) ____-i

Highest

1

Los~e~lfediua

32.3

3.9

21.6

1.531

116

730

110

14 1

75.0

3,061

196

975

696

AZ .3

12.5

1.045

233

675

2.u

‘9.1

75.0

3.830

18.5

1.275

641

7.9

7,500

Mean

systolic

aortic

has a different curve.‘” The same difference probably applies to the enlarged heart which has some areas that protrude and others that shorten during systole. Such reservations do not negate the great merit of function curves as a research method, but only imply that they yield incomplete, although valuable, information. The term cardiac asynergy has been usedlfl to designate a state of disordered teamwork betkveen the different areas of the same organ, and the more specific phrase introz~entricular (Isynergy, to signify poor coordination ljetween different muscle fibers of the same ventricle. Since, however, a complete absence of such teamlvork is OIIserved only in the presence of ventricular fibrillation, the expression dyssynergy is to be preferred. The dyssynergic effect of expansile systolic protrusions, whether due to ischemia or enlargement, or both, is 011. vious. The healthy areas are faced with the double task of expelling blood not on11 into the great arteries but also into the bulge. The fiber shortening due to the change in shape reduces the contractile strength available for the change in volume. Presumably, such a reduction in what might be called effective contractile strength will ultimately favor the development of congestive failure in patients \vho

pressure

assumed

‘2.5 2,100

1.100

failure.

359

205

7.2

for normal

I2 I7 work

7.2

28

tively.

motion trnd wasted

prerordial

792

to be 94 mm. Hg

for both.

would not be considered, by the usual criteria, to be likely candidates for it. During recent years there have been numerous reports of beneficial results after resection of postinfarctional unatomic ventricular aneurysms. One wonders whether a surgical attack on these functional (Lneurysms, i.e., areas which balloon outward only under the stress of systolic pressure, would be fruitful. Possibly, practical methods may be developed for applying prostheses that limit systolic expansion of the involved areas, without the necessity of the more hazardous procedures of cardiac bypass and of myocardial resection. These thoughts are offered not to encourage immediate clinical application, but in the hope that they may stimulate the extensive animal experimentation that should precede any such application. There is general agreement that heart failure, lvhether in the heart-lung preparation,l” in the dog with acute failure,13 or chronic failure due to induced valvular disease,” or in man,13f1Gis characterized by a decline in the ratio %yocardial

T~seful work oxygen consumption

The data herein reported suggest that one of the mechanisms responsible for such a

360

Langley,

M(lrtinez,

Fukhro,

Dmoisin,

reduction in efficiency of the left ventricle is the wasted work involved in paradoxical systolic motion. This is not the only mechanism, because there is evidence of a change in the contractility of actomyosin bands prepared from failing hearts.‘” Another mechanism is an increase in the ejection work (total stroke volume X mean left ventricular systolic pressure) without a corresponding rise in the useful work (measured stroke volume X mean aortic systolic pressure). Such a distortion obviously occurs in patients with mitral insufficiency and in those with aortic insufficiency or stenosis. Regardless of such factors, dilatation per se tends to cause mechanical inefficiency because more work is obviously required during isovolumic contraction to “lift” 300 ml. than 200 ml. of blood to the level of aortic diastolic pressure. Thus, if the stroke volume and other factors remain constant, the dilated ventricle is inherently less efficient. In any case, the data indicate that the dyssynergic effects of abnormal systolic movements associated with ischemic heart disease and with left ventricular overloads are, in some patients, of a magnitude sufficient to play an important role in reducing ventricular efficiency. Summary

An attempt has been made to determine the wasted cardiac work involved in paradoxical outward motions of the precordium. The upward displacement during systole of a known weight placed on the apical area has been measured in (a) persons with normal hearts, (b) patients with ischemic heart disease, and (c) patients with disorders that place an increased load on the left ventricle. Reasons for the opinion that the vulues obtuined for wasted left ventricular work are falsely low have been cited. The procedure did not cause consistent changes in useful cardiac work, which was serially measured in a few subjects with and without the weights on the chest. In the normal control subjects, the levels for wasted work varied between 0.1 and 5.3 gram-meters per beat, and the median was about 2.5 per cent of the normal useful (pressure X flow) work of the left ventricle. The data for patients who, in the absence of a precordial weight, had normal trac-

tend H(Lrri.son

Am. EIcnrt .T. ,Iffarc/r, 19117

ings of chest-wall motion (kinetocardiograms) were usually within the nornrxl range or only slightly above it. The patients who, without added weight, displayed paradoxical motion had values for wasted work of 5 to 45 gram-meters. Calculations were also made of the wasted stroke effort, i.e., the integral of the \\:asted work. The range and median for the subjects with normal hearts were .07 to .37 and .23 gram-meter seconds, respectively. Again, some of the patients were within the normal range, but those with pronounced systolic outward motion had values that were markedly elevated, and up to more than 30 times the normal median. Cardiac catheterization \\as perforlned in 9 of the 13 patients who had lesions that caused left ventricular overloading. In 6 of these subjects the wasted stroke work exceeded 9 per cent of the useful work (mean aortic pressure X measured stroke volume), and in 3 the wasted work was more than 24 per cent of the useful work of the same subject. The highest value found was 44 per cent of the normal value of 100 gram-meters per beat and 31 per cent of the patient’s left ventricular useful stroke work. Calculations from the data suggest that in some patien’ts lvith severe heart failure the work wasted in paradoxical systolic movements may equal the useful work. In patients at rest the cardiac inefficiency-, as judged by wasted work, appeared to parallel the clinical state more closely than did the cardiac performance, as judged by useful work. It is concluded that in some patients the work wasted in causing paradoxical systolic motion is sufficient to cause pronounced impairment of myocardial efficiency. The term ventr&lur dyssynevgy is applied to this condition, in which a portion of the energy generated by some of the fibers is diverted to stretching others. Some possible implications of this concept are discussed. Chief among them is the realization that, although knowledge of the performance (pressure and flow) of a given heart is very helpful, additional information concerning efficiency is essential for complete evaluation of its functional state.

REFERENCES 1. Coghlan, C., Prieto, G., and Harrison, T. Ii.: Movements of the heart during the period hetweet the oilset of ventricular excitation and the start of left ventricular ejection, :\M. HURT J. 62:65, 1961. 2. I’rieto, G., Coghlall, C., and Harrison, ‘I‘. Ii.: Movements of the heart during the period between the ouset of relaxation aud the beginning of ventricular filling, 11~. &ART J. 67:5X3, 1961. 3. Harrison, ‘1‘. R., Coghlan, C., and Prieto, G.: Movements of the heart durirlg ejection, ASI. ~fI?Altolic bulge> during anginal attacks, Tr. X. r\m. Physicians 71:17A, 1958. 5. Sub, Soon Kyu, Cooper, L2’. H., Frederick, \V., and Eddleman, E. E., Jr.: Force, work and power ballistccnrdiography, Am. J. Cardiol. 1:7”6, 1958. Davie, J. D., I,angley-, J. O., and EddIeman, E. T<., Jr.: Clinical and kinetocardiographic studies of paradoxical precordinl motions, i\~. HEART J. 63:775, 1962. Tenuant, Ii., and L$?ggers, C. J.: Effect of coronary occlusion on myocardial contraction, Am. J. Physiol. 112:351, 1935. Murray, G.: Pathophysiology of cause of death

from coronary thrombosis, XIIII. Surg. 126~523, 1947. Ii., Mandelbaum, I., and Schumacher, 9. Tyson, H. B., Jr.: Experimental production and study of left ventricular aneurysms, J. Thoracic & Cardiovas. Surg. 44:731, 1962. 10. Harrison, T. Ii. : Some unanswered questions concerning enlargement nud failure of the heart (Grady, Reddick lecture), i\\~. Hr:a~