Cardiodynamic and electrocardiographic changes in normal pregnancy

Cardiodynamic and electrocardiographic changes in normal pregnancy


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UCH has beml written about the heart in pregnancy. Most OS the literature deals with the clinical aspects of the condition, and it is generally felt that patients with Class I and Class IIf A cardiac conditions do well during the course of a pregnancy, and paticnt,s wit,11 II H md Class III cardiac conditions do poorly. 1IacIGnzic,’ in his book, IlWFt lXsc4r.x ,rrrcl. E’~~eq?LcoI(‘!/, t t’(%t s 1his sul)ject ttnt.irel) fro!11 the. clinical viewpoint and deals with it, for the mosi I)axt it1 geil(Bralit&. It wils wit11 the llolw 01’ Wli\l~liSlliIl, u more &finite Illat this work was started. It soon became evident, home~w, that not enough was known about the cardiocirculatory changes in the normal pregnant woman for any conclusion to be drawn wit-h respect to the changes in those pregnant women having heart disease. Although isolated phases of this problem have been studied and reported, complete correlated cardiodynamic a.nd elccl rocardiographic studies are lacking. Some of the more pertinent results reported with regard to the elcctrocardiographic findings in pregnancy arc as follows: Jermr~ and Norgaard” reported a tendency toward left axis de\-ia,tion in the early months of pregnancy with return toward the normal in the latter months of pregnancy. Xmit,h3 reported a left axis deviation in the eighth month of ljregnancy with a return toward 111~normal just bcforc delivery ol the child. Konki” reported left axis deviation and T-wave inversion in Ilead III during the latter part of ~wcgnancy with rctnrn to the normal after delivery. Carr and Palmer7 rel)ort,ed that the axis shifted t,o t.hc left during the first two t,rimesters of prcgnanq and then tended t,o shift to the right during the eight,11 and ninth month of pregnancy. (‘arr. Hamilton, and PaIm~~r” in anot.h(sr ~)apcr st.ilt,ed that. the development of a Q3 was probably an indi&ion ol a, trx~mww posit,ion of the heart during the course of the pregnancy and not a reliablt: sign of heart disease. Feldman and Hill7 taking clcrf rocardiograms on t hirty-sis normal pregnant women at the eighth and ninth months and comparing these with electrocardiograms taken after dclivcry cnncu~recl with the above mentioned findings. Nowhere in the literature could a study of the changes occurring in TIead IV during pregnancy be folmd. There is even a greater lack of pnhlishtd correlated cardiodynamic findings occurring during the cours(~ of pregnancy. Rrmge* found that M



*From the Cardiovascular Hospital, Cincinnati, Ohio. ?Classiflcation of Heart

Deputmenr, Disease,



Institute Heart















the venous pressure in a nongravid woman in the arm and leg was equal. During pregnancy the venous pressure in the leg was higher than that in the ulnar vein, and in the puerperium the venous pressure in the legs dropped far below the venous pressure in the median vein. Spitzer” concluded that the circulation time remained within t,he limits of high normal during the course of pregnancy in the normal woman. Alward”’ taking vital capacities on standing patients reported a gradual reduction during the last month of pregnancy with a gradual return to normal limits at the tenth day of the puerperium. Stander and C’addenll found a steady increase in the cardiac output from the fourth month of pregnancy amounting to over 50 per cent of the normal value as the pregnancy advanced, with a return to the normal by the third week of the puerperium. The reason for the lack of correlated data with regard to the cardiocirculatory changes during the course of pregnancy becomes obvious when viewed in the light of our experience. Forty-four normal pregnant women were studied. With every possible effort we were able to complete our observations in only nineteen cases. Examinations of some patients were discontinued because of development of urine abnormalities or marked varicosities. Others refused to return after four to six months of observation because of the rather arduous nature of tile esamination. We found it almost impossible to obtain patients in the first and second months of pregnancy. This lack of control observation was negated by the performance of a follow-up examination on the patients six to eight weeks after their delivery. METHOD



Patients were seen as early as possible during the course of their pregnancy. None was taken for examination after the fourth month. All women selected were normal. Patients who had, or who developed, positive serology, abnormal urinary findings, or abnormal blood findings were excluded. At the time of first examination a complete history, physical examination, and an x-ray film of the chest were taken. A record was made of the pulse rate, respiratory rate, and blood pressure. Then, a four-lead electrocardiogram was obtained, and vital capacity, intravenous pressure, and circulation time were measured. Care was taken to have the patient rest for thirty minutes before the procedures were started, and the intravenous pressure and circulation time were measured in the order named at the end of the examination BO as not to influence the other cardiodynamic findings. Lateral and anterior x-ray pictures of the chest mere taken at the time of deep inspiration in order to rule out, as far as possible, apparent enlargement of the heart due to a transverse position of the organ. The pulse rate, respiratory rate, blootl pressure, and vital capacity examinations were recorded with the patient in a sitting position, this being a compromise between the supine and standing positions. The fourth arm electrode with the left Landtlz that

lead of the four-lead electrocardiograms was taken with the rightplaced in the fourth interspace just to the left of the sternum and arm electrode placed on the left leg. The authors agree with Katz and the fourth left intercostal space should be the site of choice for the



OBSERI..\‘CIOXS Histoq.--The ages of the nineteen patients studied ranged from seventeen to thirty years. None of them had been seriously ill during their lives, and their past histories were relatively unimportant. They all had had diseasesof childhood, but none was left with any residuals. During the course of their pregnancies no untoward complaints were registered. Every one of them stated that, from about the fourth month on they noticed progressive tiredness and ptrogressive shortness of breath on exertion. All of t,he patients cl(~velopecl urinary fwquency and nocturia of one to three times per ewning from about the fourth month We were inclined to view the of pregnancy nnt,il time of deliver!.. frequent voiding in the light, of a decrwsed bladder capacity as a result 01’c:ompwssion by the cnluqGng ulcrus. Li~tf~r in this article wt: presenl wiclencc which shows that a burden is placed on the cardiocirculatory system by the advancing pregnaney which in the normal ease is compensated for by the physiological readjustment of that and allied systems. We, therefore, agree wit,h t,hc fundamental concept of MacKenzie,l which would the symptoms resulting from exercise as being the

effect of another burden superimposed on a system which had been working to the maximum of its functional reserve. From the seventh month of pregnancy until time of delivery, six of the patients gave a history of slight edema of the ankles toward the close of the day. This edema did not appear unless the patient was on her feet for a long period of time (six to eight hours) and was interpreted by us as being the result of uterine pressure on the common iliac veins. Physicd Estrnbinntion.-The changes produced by the advance in pregnancy were of particular interest as evidenced by the physical findings. In all of the nineteen cases there was a progressive increase in accessibility of the right ventricle as noted by palpation over the precordium. Sssociated with this observation was the fact that, as the pregnancy advanced, the pulmonic second sound became progressively more distinct and the aortic second sound diminished in intensity. Actual statistics of our eases show that the pulmonic second sound became much louder than the aortic second sound in the majority of cases (fifteen), slightly more distinct in three cases, and equal to the aortic second sound in one case. The above findings had their inception about the fourbh month of pregnancy, became more manifest until the seventh month, and then remained st.ationury or decreased sli~htlp until time of delivery. The increased intensit,y of 1.11~pulmonic stlcond sound could be espected in view of the increased accessibility of the right ventricle to palpation and our x-ray evidence of the encroachment of the right ventricle on the anterior clear space. That. t,he increased pulmonic second sound was not due to increased pressure in the lesser circulation can be indirectly inferred from the intravenous pressures obtained which showed no elevation. The decreased aortic second sound is easily understood when one views the drop in blood pressure associated with the advancing pregnancy. A systolic murmur was heard over the base of the heart and was localized over t,he pulmonic area in fourteen of the cases. It was usually first heard in the third to the fourth month, became progressively louder until the seventh to eighth month, and then remained stationary or decreased slightly in intensity until time of delivery. At the time of post-partum examination the systolic murmur, like the other cardiac abnormalities, had disappeared. Two cases developed a split second sound at the base during their pregnancy. In the nineteen cases studied, no murmurs were heard at the apex. One case (Mrs. 33. C., No. 20) had a palpable thrill accompanying the systolic murmur at the base. The origin of the systolic murmur at the base is not well understood. The fact that it tended to disappear with deep inspiration may point to a kinking of the pulmonic artery as a causative factor, the kinking being relieved by the descent of the heart with the diaphragm on deep inspiration. On the other hand, the systolic murmur at the base may be of



.iBrfirtrC.\N 1IIwRT


c.;ll,cliorcspiratory~spirator~origin. This last interpretation does not explain the ])ullllonic thrill found in on(’ 01’thcL easesreported and two others noi irtcludcd in this scricx. Rible I condenses these findings. ‘I3\l{l.k: I

13 n a 10 11

15 17 18 20 “2 22 24 1” 1; 31 27 29


+ &














1 +
























c-Split second sound at base tAystolic thrill pulmonic area




+ i-

-.. ..- --.

Blood P~essurc.-If one can consider the final blood pressure taken, at the time of follow-up examination, six to eight weeks following delivery, as being the average normal, it will be noted that the systolic pressures l’all in a linear fashion during the first four months of pregnancy. The average fall for nineteen caseswas 13 mm. of mercury. The same is true of the diastolic pressures, the average fall for the nineteen casesduring t,be first four months of pregnancy being 17 mm. of mercury. From the fifth to the seventh months of pregnancy 6he average systolic and diastolic pressures do not change appreciably. From the seventh to the beginning of the ninth month there is a slight but definite rise as shown by the average systolic and diastolic pressures. At the time of ~)ost~partum examination the average systolic pressure had risen 11 mm. mercury and the average diastolic 14 mm. mercury. If one scrutiniz(bs 1he data, one will find that the trend of both systolic and diastolic l)rtassure in each individual case absolutely parallels the reported averag:ca trend. A definite expla.nation for the lowered xyst,olic and diastolic. pressures during the height of the pregnancy can be found if one takes into account the enormous blood reservoir created in the pregnant uterus and compares this condition t,o casesin which slight degrees of spla.nchnic










dilatation occur. When the process of lightening occurs, the blood reservoir is decreased as a result of pressure exerted by the confines of the pelvis, the rise in systolic and diastolic pressures during the eighth and ninth months being proportioned to this dynamic effect. When the uterus is emptied, the blood reservoir disappears with the delivery of the placenta and six to eight weeks post parlum the pressure is again at the nortn. I’&~ asd Rwpimtory Z2ates.-The pulse and respiratory rates gradually increase until the seventh month of pregnancy. From the seventh to the eighth mont.11 the pnlsc> rate continues to rise while the respiratory


L-Graphic and

representation respiration

of systolic rates through

and diastolic the months

blood pressu~s, of pregnancy.



rate levels off. From the eighth month the trend of both rates is sharply downward until at the time of examination after delivery the average pulse rate was 72 per minute and the average respiratory rate 16 per minute. The trend of the pulse rate and the respiratory rate is an index of an attempt to compensate for an embarrassed circulation. The trend of these two rates again fits in with the picture seen in slight degrees of splanchnic dilatation. Figure 1 graphically illustrates the trends pressures and the pulse rate and respiratory pregnanc,y.

of the systolic and diastolic rate during the course of

I~fltfYLcenOfLSZ’/‘essfl,‘e,s.--In general. intravenous pressures had a tendenuy to start al, a fairlp high Iewl (80 to 100 cm. of water) in the early months of pregnancy-. thrn dnrrcasc until about the sisth lo the seventh Freqwnt,I~ month and t,hen incwasc until the time of final esaminat.ion. they did not ret urn I o t h(? Icvcl of t.he lwevions highest; pressure and in three women rcmaincd at the level fow~d during t Iw ninth month. From the data one is justified ill stat inx 1 Ililt iti IIlC Jtl;l,jOl?l.)~ Of (YlSeS Ille intravenous prrssurcs are at 6hcir Iowwf ahout t,Iic sixth to the seventh month. Th(~ rangck of 1 hc inttxvc>lrous prc~ssurcs in all cases did not. esceed 48 lo 110 ~111. 01’ watc11*. Tf’ 1hcl inil.ial venous l~twsure was high, the drop during t IIC sist.11 I o tile sc~\~t~nth month di(l not wach the low levels found ai. the samt1 period in those cases starting with a relatively low initial int,ravenons pressiirc~. Thus we we tllal. the intrarcnous I)t’essures fall within Ihe high nomlal mnges (40 lo 1-M cm. of’ water j. cwtablished by Gcorgt! C’. Griffith iIntl his associatw.‘” who used the sam(’ technic. The tentlrrwy of thca il~tra\~cnous pressures IU drop during the middle month of 111~prcgnanc~y sct’ltw io wincidc wit II the ch*op in ldootl pressures. The t.cndcncy towarc a slight rise in 111~int,ratrcnous prrssures from the sevc1lt,Ii to Ihe ninlh mont,Ii also roughlp parallels the absolute trend of the l~lood Inwsurcs. ISowever, f he l.lwld of tllc intravenous pressures Ihroughout. prcgnanay is not. nearly as definite as that of the blood prc~ss~~~es. i\ga in one can see the phenomenon of the changing rolumc of a large blood Jxwrvoir mirrorccl 1o some cstent in the intravenous pressure findiiigs. Ciw&tion Tinw.-The circulat,ion t,ime ranged from nine t,o sisleen seconds in t,he nineteen cases studied. The majority of patients ranged from ten to fourteen seconds. There was no definite trend throughout the course of pregnancy. These findings agree with work of Spitz? and fall within the limits of normal. WC fcrl that the rrlatively st,ationa.r> circulation time is ;I resultant of 1he prrviously mc,ntioncd trends of blood prcss~ux~, int,ravcnons pressure, pulse rate, respiratory rate, and II Ilas 1,cen s110\w 11). St;lndt~r mtl ( ‘ilddC11” that 1’lvlll cardiac output. t,he fourt,h monih of pwgnancy io frill t(w1 thrw is :I sttaady increase in rardiar output, ;Inlc,mltillg to ill)~~~ll .-d) l,ct. cc>?lt of tlw JlolXlLll. This increase in c;rtdi;lv olltpltt again fits i~rto tllc pictaw and m;ly PllII~ be accountrd for by Ilic inewascs in l)lllst~ t31 c wjthonl 1)rcsupposing an associated rnlargemrnt of tlic vrntrichx Vital Cnpacit,tf.-On the Wholly, t,lw vital caparit irs on successive months did not show any definite trend during the COLWSC of pregnancy. To 1)~fure, tht~w was a monthly val*iation of 100 to 200 C.C.and in sonw few isolated instances there w-as a dv~.iation of as much as 300 C.C.from the preceding month. These variations wrre in the nature of an increase or a deercase from 1-1x1 mean. For thcx most part, the monthly variations in the vital capacities werr not in rwcss of what one finds in a normal person from day to day.










,$t first we were of the opinion that the vital capacity of a patient would increase as the pregnancy advanced. Recalling Hoover’s’” work with regard to diaphragmatic excursions we expected this since the dome of the diaphragm is greatly elevated during the course of l)rcgmnmy. However, there is a marked increase in the intra-abdominal pressure. Therefore, any given vital capacity must be viewed as a resultant of these contracting forces. Increase or decrease of the vital capacity depends on which force is in ascendancy. This is in turn modified by the patient’s position. From clinical and x-ray evidence there can be no doubt that the residual capacity of the lungs is greatly diminished. X-vay Examination of Ckest.-The anterior view of the chest showed cleration of the diaphragm from the fourth month on. It must be realized that the x-ray examinations of the chest were done at the height of a deep inspiration. These silhouettes show that during the middle months of pregnancy the diaphragm on both sides was elevated on an average of 2 cm., above the normal. At this time the oblique and transverse diameters of the heart, show-cda 0.5 cm. to 1 cm. increase over the normal size. The corresponding lateral views, even at the time of deep inspiration, showed some degree of encroachment on t,he anterior clear space by the right ventricle. The average increase of the anteroposterior diameter of the heart in the nineteen casesst,ndied during the middle months of pregnancy was about 1 cm., over the normal. As the pregnancy advanced, t,he heart was pushed upward and forward. This was to be expected when one recalls that the heart rests for the most part on the left anterior slope of the diaphragm. S-ray silhouettes taken with the patient holding her breath in midtidal respiration showed a marked elevation of the diaphragm and a definite encroachment of the right ventricle on the anterior clear space. It is our opinion that the small increases noted in the various diameters of the hea,rt during deep inspiration cannot be interpreted as being the result of the cardiac enlargement. We feel that they are an expression of a more transverse position of this organ as a result of the average diaphragmatic elevation of 2 cm., encountered at this time. This elevation of the diaphragm agreed with the results of Hynemann,” who found that during the early part of the third trimester the right side of the diaphragm was elevated on the average of 2 cm. and the left side of the diaphragm on an average of 2.1 cm. He also noted that the heart had assumed a more transverse position at this time. In addition to these x-ray findings and their interpretation, our contention that the heart is not enlarged during pregnancy is further supported by the fact that a searching review of our cardiodynamie findings failed to give any evidence which a priori would demand cardiac enlargement for its explanation. In the first place the blood pressures, systolic










an attendant slurring of the QRS complex in some instances ((.‘ascs 3, 7, 23, and 27), and the development of an ‘ *ironed out” or inverted T-wave in all six cases. Two of the six cases ((.‘ases 23 and 27) showed a small Q-wave at the time when the voltage was lowest (Fig. 4). Case 3, which is typical of this group, lends further support to the belief that in this study a progrcssivc lowering of thtx voltage is t,he first stage of a definite axis shift. AI, the eighth month when the QRS was at its lowest voltage and markedI\- slurred, a forced expiration which lifted the diaphragm higher, produced a definite invertctl QRS complex in which the R-wave was absent, (Fig. 5).





sent electrocardiograms that show definite left axis shift. Three of these cases (CIases 15, IX, and 22) developed the W-type of wave which in the early months of pregnancy appeared as a normal QRS complex with a small but definite Q- and S-wave. Case 15 demonstrated t,his t-pc of change. All three cases presented a flattening or inversion of the T-wave some time during t,he course of the pregnancy. and slurring of the QRS complex (Fig. 6). The other three cases (Cases 1, 20, and 24) showed the development of a left axis shift’ during the course of the pregnancy. All three of these had slurring of the QRS complex and two (Cases 1 and 24) show the usual alt,cration in the T-wave (Fig. 7).

Group III is composed of two casts (Cases 10 and 3) which are distinctly different from the rest. In the earlier months of pregnancy the QRS complex had a diphasic character with the initial Q dcfleetion, although small, being larger than thus H deflection. *\s pregnancy advanced, the voltage increased and the R deflection bcc~ame larger than t.hc Q until the eighth month of pregnancy, when the original Q deflection was represented by an upstroke of the K deflection, .\I the t,ime of final examination the QRS complex was again cliphasic, the Q being larger than the R. Both of these cases show the usual T-wave changes (Fig. 8d. Group IV was created because the final case (Case 3) could not be placed in any of the preceding groups. Lead III did not change al)preciably throughout the pregnancy. The P-wave was inverted throughout the study. The initial dcflcction of the QRS complex was small and

upright. The major deflection was down and inverted. Actually the QRS complex was diphasic, but, it l)rrsent.ed the pick-e of a definite permanent left axis shift. The T-wave went through the usual changes and at the time of final examination it was diphasic in character. As far as we could ascertain, the patient did not have any heart discasc and was perfectly normal (Fig. 9). In all of the ninet,een cases definite changes were noted throughout the course of pregnancy in Lead IV. For the most part these were shown by the shifting of the S-T segment, which had a tendency to change from a negative take-off to a,n isoelectric take-off and by the T-wave, which became diphasic in some instances, even upright and positive. The QRS complex frequently changed in amplitude during the course of the pregthe initial Q deflection became smaller. Sevnancy. Quite frequently eral of the cases showed definite slurring of the QRS complex. Cases 7, 19, and 21 showed these changes (Fig. 10).










The electrocardiographic changes can be explained for the most part on the basis of a left axis shift. Einthoven and his eoworkers18 have shown that the transverse position of the heart at the end of expiration is associated with a tendency toward, or with an actual, left axis deviation as noted in a standard three-lead electrocardiogram. (‘ohn and RaisbeckI have also shown that. the left axis deviation in the electrocardiogram is associated with a greater transverse position of the heart and that right axis deviation tends to occur as t,hc position of the heart becomes more vertical. Smith,3 Ronki,” Jensen and Norgaard,2 Carr and





Palmer,5 and Feldman and Hill,; from their studies of the convent.ional three-lead electrocardiogram taken of pregnant women, came to the conclusion that the changes observed are the result of left axis deviation. Feldman and Hill studied electrocardiograms taken at the eighth and ninth months of pregnancy and shortly after delivery. They did not have the opportunity of studying more complete records. The same was true of Carr and Palmer, who, in their article make a plea for a more comprehensive electrocardiographic study of the normal pregnant woman throughout the entire term of pregnancy. Just why only four of our cases showed T-wave changes during the course of pregnancy is not understandable. However, our findings are

in aword with thosr of P’eldman and Hill, who report 1’:; inversions in only four of their thirty-six WSW. vdTc feel that t Ire reason for tllc electrocardiographic changes noted in all of our cases is definitely thta result of monthly examination. It, might be postulated t,hat the one cast& that showed a complrtr left axis deviation t,hroughout the period of pregnancy and at tirncl of final txamil~;lt ion bclongetl in the, group showin+z




T, changes becauset,hc records did show slight changt~sin th T-wave in Lead III. It is our belief t,hat t,he development of a Q-wave of various magnitudes during the course of tht~ pregnancy is nothing more than an expression of a left axis shift, and WC concur in this belief with Carr, Hamilton, and Palmer.” Surely our records cannot be interpreted on any other basis. The changes noted in Lead IV (S-T and T-wave changes) have already been commented upon. They are of importance because of their










constancy. There were further changes noted with regard to the relationship of the amplitude of the Q- and R-waves which could not be interpreted because of their inconstancy. It has been stated by several observers that changes, especially the slurring encountered in the electrocardiogram of the pregnant woman, are the result of toxemia. Jensen and Norgaard felt that the clectrocardiographic changes in the pregnant woman were due to the alternating hgpcrtrophy of the ventricles. We can show defiuitely that these In the first place these two statements are two opinions are erroneous. highly improbable when viewed in the light of clinical and cardiodynamic findings of these nineteen normal pregnant women. In the second place, time after time when the third lead showed masimum changes, a normal third lead could be obtained by nmking the patient take a maximum inspiration. The following record (Fig. 11) illustrates this and renders untenable an organic explanation for t.he electrocardiographic changes seen durin, 0’ t,he course of a normal pregnancy (C’ase 27, Lead III, at ninth month). Tahlc II summarizes the ninctccn case histories.



Nineteen normal pregnant women were studied t,hroughout the course of t.heir pregnancy, and the final examinations were made from six to eight weeks after delivery. The study included the correlation of clinical, cardiodynamic and electrocardiographic findings during the period of pregnancy and puerperium. The final examination, approximately two months after delivery, was taken as the control for each case. The correlation of these findings led us to the following conclusions: 1. Pregnancy tem.


places a burden

on the cardiocirculatory


2. In the normal woman this burden is of the magnitude that can be compensated for by calling on the reserve capacity of this system. 3. The method of compensation for the increased burden is both mechanical and physiological in nature. 4. The electrocardiographic changes observed during the course of pregnancy may be definitely interpreted on the basis of mechanical shifting of the heart.


24 30 19 20 RO “8 19


26 20 18 28

30 28 28 30

19 30 &


2 3 7 8 10 11 12


17 18 890

21 22 23 24

27 29





0 0

0 0 0 0 0 tl


0 n 0

0 n 0 0 ::



multip. primip. multip. prim+. multip. multip. multip. multip. multip. multip. multip. multip. multip. multip. multip. multip. n&tip. (dystocix) multip. primip. Wassermann tests.


mo. mo. mo. mo. mo. mo. 1110.


mo. mo. mo. mo. mo. mo. mo. mo. mo.



4th. mo. 4th mo.

3rd 4th 4th 4th 3rd 3rd ::ld


3rd 4th 3rd 4th 4th 4th 3rd Zrd 4th



Neg. Neg.

Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg. Neg.




Nor. Nor.


Nor. Nor. Nor. Nor. Nor. Nor. Nor. Nor.


Nor. Nor. Nor. Nor. Nor. Nor. Nor.







Nor. Nor. Nor. Nor. Nor. Nor. n’or. Nor. Nor. Nor. Nor. Nor. Nor. Nor. Nor. Nor.







~lyspnea tlyspnea

clyspnen, nausea, rlyspnea

+L, fatigue ++, fatigue A+, fatigue

dyspnea dyspnea dyspnea

++, fatigue I+, fatigue

polyurin vomiting ++, fatigue


and nocturis ++, dyxpnea



diuria nausea


++ A*



++ ++ *a

++ f, diurin

No No

No No No No No No No No No No No No INO No No No No

abnormalities abnormalities

abnormalities abnormalities abnormalities abnormalities abnormalities abnormalities :tbnormnlitiw abnormalities abnormalities abnormaliCes abnormalities abnormalities abnormalities abnormalities abnormalities abnormalities abnormalities











5. This shifting of the heart produces a left axis deviation in the electrocardiogram of the majority of the patients studied. 6. The normal woman who does not develop any untoward signs or symptoms during the course of pregnancy shows normal clinical, cardiodynamic, and electrocardiographic findings sis to eight weeks after delivery. John Oldham, for Grateful appreciation is acknowledged to the following: terhnicxl assistance, and the American Red Cross, whose aid made this study possible. REFERENCES 1. MacKenzie 2.

3. 4. 5. G.

: Heart Disease and Pregnancy, New York, 1921, Oxford University Press. Jensen, F. G., and Norgaard: Functional Cardiac Disease and Essential Cardiac Hypertrophy in Normal Pregnant Women, Acta. Obst. et gynec. Scandinav. 6: 67, 1937. Smith, S. C.: Observation on the Heart in Mothers and Newborn, J. A. 11. A. 79: 3, 1922. Konki? V.: The Electrocardiogram of the Heart in Pregnancy and Puerpenum, Jap. J. Obst. and Gynec. 12: 2, 1929. Carr, F. B., and Palmer, R. S.: Observation on Electrocardiography in Heart Disease in Pregnancy With Special Reference to Axis Deviation, AX. HEART J. 8: 238, 1932. Carr, F. B., Hamilton, B. E., and Palmer, R.: The Significance of Large Q, in Lead III of the Electrocardiogram in Pregnancy, AM. HEART J. 8: 519,


7. Feldman, L., and Hill, Harold H.: The Electrocardiogram of the Normal Heart in Pregnancy, AM. HEART J. 10: 110,1934. 8. Runge, H. R.: J. A. M. A. 83: 567, 1924. 9. Spitzer, Die Blutstromungsgeschwindigheit in normaler und gestorter Walter: Schwaneerschaft. Arch. f. GvnLk. 154: 449. 1933. 10. Alward, H: C.: The Vital Capacity in the Last Month of Pregnancy, Am. J. Obst. & Gynec. 20: 373, 1930. 11. Stander, H. J., and Cadden, J. F.: The Cardiac Output in Pregnant Women, Am. J. Obst. & Gynec. 24: 13, lQ32. 12. Katz, The Effect of Standardized Exercise on Louis N., and Landt, Harry: the Four-Lead Electrocardiogram, Am. J. M. Se. 189: 346, 1935. 13. Wilson, F. N., Macleod, A. Garrard, and Barker, Paul R.: The Order of Ventricular Excitation in Human Bundle-Branch Block, ABI. HURT -T. 7: 305, 1931-1932. I -t. Griffith. G. C., Chamberlain, C. T., and Kitchell, J. R.: Simplified Apparatus for Direct Venous Pressure Determination Modified From Moritz and von Tabora, Am. J. M. Sr. 187: 371, 1934. 15. Griffith, G. C.. Chamberlain, C. T., and Kitchell, J. R.: Observation on the Practical Significance of Venous Pressure in Health and Disease With a Review of the Literature, i\m. J. M’. SC. 187: 642, 1934. 16 Hoover, C. F.: Respiratory Excursion of the Thorax, Oxford Medicine II. Part I. D. 29. 17. Hyneman’n-quoted by Konki.4 18. Einthoven, W., Fahr, G., and de Waart, A.: Ueber die Richtunq und die manifeste Grosse der Potentialschwankungen im menschlichen Herzen und den Einfluss der Herzlage auf die Form des Elektrokardiograms, Arch. f. d. ges. Physiol. 150: 275, 1913. 19. Cohn, A. R., and Raisbeck, M. T.: The Relation of the Position of the Heart to the Electrocardiogram, Heart 9: 311, lQ22.