echocardiography in acute myocardial infarction

The American Journal of CARDtDLOOY

VOLUME 36

NUMBER 1

CLINICAL STUDIES

Echocardiography in Acute Myocardial Infarction

BETTY C. CORYA, MD

SUSAN RASMUSSEN, RN, MSN

SUZANNE B. KNOEBEL, MD, FACC

HARVEY FEIGENBAUM, MD, FACC

with the technical assistance of MARY JO BLACK, BA

Indianapolis, tndiana

From the Krannert Institute of Cardiology and the Department of Medicine, Indiana University School of Medicine, Indianapolis, Ind.. and the Hendricks County Hospital, Danville, Ind. This study was supported in part by the Herman C. Krannert Fund, Indiinapolis, Ind.; by Grants HL- 06308, HL-05363 and HL-05749 from the Na- tional Heart and Lung Institute of the National In- stitutes of Health, Bethesda, Md.; by the Indiana Heart Association, Indiinapolis, Ind.; and by a Grant-in-Aid from the American Heart Associa- tion, Northeast lndiina Chapter, Inc., Indianapo- lis, Ind. Manuscript accepted December 11, 1974.

Address for reprints: Betty C. Corya, MD, In- diana University Medical Center, 1100 West Michigan St., Indianapolis, Ind. 46202.

Sixty-four patients with acute transmural myocardial infarction had daily echocardiograms while in the coronary care unit. Patients with previous infarction were excluded. The electrocardiographic site of infarction was anterior wail in 28, inferior wall in 33 and both anterior and inferior wall in 3 patients. Echocardiograms satisfactory for inter- pretation were obtained in 92 percent of cases. Abnormal left ventricu- I& viral1 motion corresponding to the electrocardiographic site of infarc- ?’ tion was seen in the echocardiogram in 84 percent of cases. Exagger- ated normal motion in noninfarcted areas was seen in 30 percent. The left ventricular internal dimension correlated with clinical heart failure (P <0.005) and was increased in 50 percent. Abnormal mitral valve closure, which reflects increased lefl ventricular end-diastolic pressure, was preseni in 33 percent. This finding did not correlate significantly with clinical heart failure. By combining the measurements of left ventricular internal dimenslon and mitral valve closure, it was possible to predict hospital mortality from the echocardiograms. The results indicate that echocardiography is a useful technique in the study and management of patients with acute myocardiai infarction.

Although present echocardiographic techniques do not permit identi- fication of echoes from the coronary arteries and, therefore, direct as- sessment of the presence and severity of coronary artery disease, some of the important consequences of coronary artery disease may be indirectly evaluated by examination of the left ventricle.l-g Most previous studies have dealt with abnormalities of wall motion1-3 and left ventricular volume4-6 in patients with chronic coronary artery disease. Less information is available on the use of echocardiography in patients with acute infarction. Change in motion of the posterior left ventricular wall has been shown in animals with experimental infarction of the posterior wall. 7y8 These changes in posterior wall motion were presumed to be due to segmental left ventricular dysfunc- tion since they were not seen in dogs with apical infarction.8 In addition, decreased posterior wall velocity has been demonstrated in patients with inferior as opposed to anterior infarction9 and abnormal

July 1975 The American Journal of CARDIOLOGY Volume 36 1

ECHOCA~AFWY IN ACUTE INFARCTION-CORYA ET AL.

FIGURE 1. Normal left ventricular echogram showing where surements were made. EN, = amplitude of endocardial echo ographic motion; LS, = amplitude of left septal echocardiog motion during ejection; LVIDd = left ventricular internal dimenr enddiastole.

! mea- xardi- graphic sion at

anterior left ventricular wall motion has been demonstrated in patients with transmural anterior infarction.* Good correlation has been reportedlO between echocardiographic and dye-dilution methods of measuring cardiac output in nine patients with acute infarction.

Because of the noninvasive nature of echocardiography and its potential usefulness in assessing both segmental and generalized left ventricular function, investigation into its use in acute infarction is indi- cated. Among the many questions that need to be asked are: (1) How often can technically satisfactory echocardiograms be obtained in patients with acute myocardial infarction; (2) what are the incidence rates and sites of abnormal left ventricular echocardiographic motion, and what is its relation to the electrocardiographic site of infarction; (3) how soon after infarction do abnormalities of echocardiographic motion occur; (4) what is the relation of echocardiographic findings to clinical heart failure; and (5) are echocardiographic measurements helpful in predicting mortality in acute infarction? This report deals with these questions.

Methods

Patients: Clinical and echocardiographic data were col- lected from 64 consecutive patients with acute transmural myocardial infarction. Patients with a history of previous myocardial infarction were excluded. All patients were examined daily by the same investigator and were included

FIGURE 2. Left ventricular echograms recorded with the transducer overlying the anterior left ventricular wall (ALV). A, normal subject. The motion is away from the chest wall (normal) during ejection. 6, from a patient with acute anterior wall myocardial infarction. The anterior left ventricular wall motion during ejection is paradoxical.

2 July 1975 The American Journal of CARDIOLOGY Volume 36

EC+0CcrRMoQRApHy IN ACUTE tiARCTKN-‘XRYA ET AL.

only if diagnostic electrocardiographic changes (Q wave greater than 0.04 second) of transmural infarction plus typ- ical chest pain or a characteristic curve of serum enzyme activity, or both, was present. A diagnosis of congestive heart failure was made when the patient manifested bilateral basilar rales that did not clear with coughing or a third sound gallop, or both, consistent with the Killip classification.

Echocardiograms: Echocardiograms were obtained at the bedside as often as possible-in most cases daily- while the patients were in the coronary care unit. A Smith- Kline echograph with a 2.25 megahertz transducer 1.25 cm in diameter and collimated at 7.5 cm was used to obtain echoes. M mode tracings were made with a portable Hon- eywell Model 1856 strip chart recorder. A simultaneous electrocardiographic monitoring lead was recorded on each tracing.

Echoes were first recorded from the mitral valve. From that position a sector scan of the left ventricle from base to apex was recorded, as previously described,l’ in more than one interspace when possible. The transducer was then moved laterally 5 to 7.5 cm across the chest to record echoes from the anterior left ventricular wall. Details of this technique have previously been described.s

Echocardiographic measurements: The echocardiograms were interpreted without knowledge of the clinical information. Figure 1 illustrates a normal left ventricular echogram and shows where the measurements used for analysis were made. The left ventricular internal dimension at end-diastole (LVIDd) was taken at the peak of the R wave in the electrocardiogram at about the level of the posterior leaflet of the mitral valve. This was divided by the body surface area to obtain an LVIDd index. The normal LVIDd index in our laboratory is 3.2 cm/m2 or less. The amplitude of left septal and left endocardial echocardiographic motion during ejection was measured at or just below the posterior mitral valve leaflet. Normal septal motion in our laboratory ranges from 0.3 to 0.8 cm (mean 0.6)

and normal endocardial amplitude ranges from 0.8 to 1.6 cm (mean 1.3). Paradoxical septal motion was given a value of 0. Motion of both the septum and endocardium at the apex was also observed.

The anterior left ventricular wall echo was called normal if it moved away from the transducer during ejection and abnormal if it was flat or moved-toward the transducer during ejection. (Fig. 2, A and B)

The period of mitral valve closure (A-C interval) was measured from the peak of the A wave in the mitral echogram to the point where the echoes from the anterior and posterior mitral leaflets met (Fig. 3). Abnormal mitral valve closure, which has been shown to be associated with increased left ventricular end-diastolic pressure,12 was de- fined as a P-R minus duration of mitral closure (PR-AC) interval of 0.06 second or less. The duration of mitral valve closure is subtracted from the P-R interval in the electrocardiogram since the time between atria1 and ventricular contraction also affects mitral valve closure.13J4 As the mitral valve closure time increases, presumably because of increased left ventricular pressure, the PR-AC interval de- creases if the P-R interval remains constant.

Statistical analysis: Data were analyzed by the Student t test. Chi square analysis was used to find if there was a relation between the echocardiographic measurements and congestive heart failure and to determine the ability of the following variables and combinations of variables to predict mortality on admission and at the time of the last echocardiogram (excluding admission echocardiogram): (1) elevated LVIDd index; (2) abnormal mitral valve closure reflecting increased left ventricular end-diastolic pressure; (3) elevated LVIDd index plus abnormal mitral valve closure; (4) LVIDd index/PR-AC ratio as a volume/pressure ratio; and (5) abnormal wall motion.

Clinical variables analyzed by the same statistical methods were (1) age greater than 60 years; (2) sex; (3) serum glutamic oxaloacetic transaminase level greater than 250 units; (4) location of infarction; (5) third sound gallop; (6)

FIGURE 3. Mitral valve echograms showing abnormal mitral valve closure (P-R interval of electrocardiogram minus A-C interval = 0.06 second or less). The config- uration of the A-C echo is variable. A = point at which the mitral valve begins to close: C = point of complete closure of the mitral valve. IIuIlIlul abnormal


ECHCCARDKMRAPHY IN ACUTE INFARCTION-CORYA ET AL.

TABLE I

Echocardiographic Data

Electrocardiographic Site of

Transmural Infarction

Normal Anterior Inferior Both

(17 cases) (28 cases) (33 cases) (3 cases)

LSa (cm)

Measured (no.)

Range

Mean

P value

no. abn (<0.3)

(>0.8)

ENa (cm)

Measured (no.)

Range

Mean

P value

no. abn (<0.8)

(>1.6)

ALV

Recorded (no.)

no. abn

17 25 31 3

0.3-0.8 O-.6 O-2.0 O-l.1 0.63 0.08 0.81 0.37

<O.OOl <0.025 NS

20 (80%) 1(3%) 2 (66%) None 12 (39%) 1(33%)

17 25 28

0.8-1.6 0.8-2.1 o-1.7

1.29 1.40 0.66

NS <O.OOl

None 16 (57%)

4 (16%) 2 (7%)

17 21

13 (76%) 1(5%)

o-1.3

0.60

<O.OOl

2 (66%) None

3

3 (100%)

LVIDd index (cm/m*)

Measured (no.) 17 27 31 3

Range 2.2-3.3 1.9-4.4 2.4-4.3 2.9-3.7

Mean 2.8 3.3 3.0 3.4

P value <O.OOl <0.05 <0.05

no. abn (>3.2) 1 19 (70%) 11 (35%) 2 (66%)

MV closure

Measured (no.) 22 22 3

no. abn PR-AC 11(50%) 9 (41%) 1 (33%)

(50.06 second)

abn = abnormal; ALV = anterior left ventricular wall echo;

ENa = amplitude of endocardial echocardiographic motion;

LSa = amplitude of left septal echocardiogra.phic motion dur-

ing ejection; LVID,, index = left ventricular internal dimension

at end-diastole/body surface area; MV = mitral valve; P = prob-

ability. PR-AC = P-R interval from the electrocardiogram minus

the A-C interval from the mitral valve echogram.

bilateral rales; and (7) presence of heart failure on the basis of the Killip classification.

Results

Clinical Data

The 64 patients ranged in age from 31 to 85 years (mean 60) and included 36 men and 28 women. Con- gestive heart failure was present during the first 48 hours in 58 percent (37 of 64), and 4 patients had pulmonary edema and 2 had shock on admission. The hospital mortality rate for the entire group was 23 percent (15 of 64). The electrocardiographic site of infarction was anterior wall in 28, inferior wall in 33 and both anterior and inferior wall in 3 patients.

The group of 28 patients with anterior wall infarction included 17 men and 11 women whose ages ranged from 40 to 82 years (mean 60). Congestive heart failure was present within 48 hours of admission in 64 percent (18 of 28), and the hospital mortal-

ity rate was 32 percent (9 of 28). The 33 patients with inferior wall infarction included 16 men and 17 women whose ages ranged from 31 to 85 years (mean 59). Fifty-two percent of these patients (17 of 33) had congestive heart failure within 48 hours and the hospital mortality rate was 15 percent (5 of 33). The three patients with both anterior and inferior wall infarction were men aged 51 to 66 years (mean 58). Two had congestive heart failure, and one died in the hospital.

Echocardiographic Data

Echocardiographic data for the three groups are presented in Table I. The most obvious echocardiographic abnormalities were those of left ventricular wall motion. Decreased or paradoxical echocardiographic motion was found on admission in 84 percent of patients (54 of 64) with acute transmural infarction. The echocardiograms in Figures 4 and 5, obtained from two patients in this study, demonstrate, respectively, abnormal septal and posterior wall motion. In 73 percent of patients (47 of 64) abnormal motion was seen at the “base” of the heart where the ultrasonic beam traverses the mitral valve and where standard left ventricular echocardiographic measurements are made. In four instances the abnormality was seen only at the apex, and in three cases only the anterior left ventricular wall was abnormal. “Exag- gerated normal” motion in areas not involved electrocardiographically was seen in 30 percent of this series of patients. The area of decreased or paradoxical motion corresponded to the electrocardiographic site of infarction with two exceptions. One patient with inferior wall infarction had abnormal anterior left ventricular wall motion as well as decreased endocardial motion, and another with only inferior wall infarction electrocardiographically had absence of septal motion at the base of the heart in addition to abnormal endocardial motion.

The abnormal motion associated with acute infarction was nearly always seen in the admission echocardiogram, and very little daily change was seen in sub- sequent tracings in the coronary care unit. Although it was not possible to quantitate the area of abnormal contraction, the changes appeared to be greater and more extensive than those we have observed in patients with chronic coronary artery disease; prelimi- nary observations in follow-up tracings (3 to 6 months) indicate that some improvement occurred later.

Patients with anterior wall infarction: Left septal echoes were adequate for measuring amplitude of motion during ejection in 25 of the 28 patients with electrocardiographic evidence of anterior myocardial infarction. Eighty percent (20 of 25) had ab- normally decreased motion (less than 0.3 cm) with a mean of 0.08 cm (range 0 to 0.6) that was significantly different from normal (P <O.OOl). The endocardial amplitude was also measurable in 25 patients, and the group mean was not significantly different from normal. Four patients had endocardial amplitude values above the normal range (0.8 to 1.6 cm). Anteri-


EWOCARMOQRAW lN ACUTE ffARCTK)N--CORYA ET AL.

sence of left septal echo motion.

or left ventricular echocardiographic motion was abnormal in 76 percent (13 of 17) of those in whom it was recorded.

The left ventricular internal dimension at end- diastole &VI&) index was elevated in 70 percent (19 of 27) of these patients, and 50 percent (11 of 22) of them had abnormal mitral valve closure.

Patients with inferior wall infarction: Left septal echoes could be measured in 31 of 33 patients with inferior wall infarction. Values ranged from 0 to 2.0 cm (mean 0.81). The left septal amplitude was less than normal in only 1 patient and was greater than normal in 12 patients (P <0.025). Endocardial amplitude ranged from 0 to 1.7 cm (mean 0.7), with 2 patients having values greater than normal and 16 having values below the normal range (P <O.OOl). Anterior left ventricular wall motion was abnormal in 1 of the 21 patients in whom it was recorded. The left ventricular internal dimension index was elevated in 35 percent (11 of 31), and abnormal mitral valve closure was present in 41 percent (9 of 22) of these patients.

Patients with both anterior and inferior wall infarction: Measurements in the three patients with both anterior and inferior electrocardiographic changes showed septal motion increased in one and decreased in two, endocardial motion decreased in two, anterior left ventricular echo motion abnormal in three, left ventricular internal dimension index el-

FIGURE 5. Left ventricular echogram from a patient with acute inferior wall infarction showing greatly decreased posterior wall motion and normal septal motion.


ECHCCARDKMRAWY IN ACUTE INt=ARCTlON-CORYA ET AL.

TABLE II

Analysis of Echocardi.ographic Measurements in Predicting Mortality in Acute Myocardial Infarction

Patients Patients in Whom Value

Echocardio- Examined Could be Measured Patients with Normal Value Patients With Abnormal Value

Measurement gram (no.) no. Mortality no. Mortality no. Mortality P Value

LVIDd index First 64 61 15/61(25%)

Last 40 40 7/40 (18%)

:8” 4/29 (14%) 32 11132 (34%) 3/18 (17%) 22 4/22 (18%) N”:

MV closure First 64 47 9/47 (19%) 26 3/26 (12%) 21 6/21(29%) NS

(PR - AC) Last 40 35 7/35 (20%) 17 o/17 18 7/18 (39%) <0.005

MV closure + First 64 46 9/46 (20%) 3135 (9%) 11* 6/11(55%) <O.OOl

LVlDd index Last 40 35 7/35 (20%)

z*

3/26 (12%) 9 4/9 (44%) <0.05

LVIDd index/ First 64 46 9/46 (20%) 33 3/33 (9%) 13 6/13 (46%) <0.005

PR-AC Last 40 35 7/35 (20%) 27 1127 (4%) 8 6/8 (75%) <0.0001

LSa First 64 59 15/59 (25%) 23 4/23 (17%) 36 11/36 (31%) NS

Last 40 38 8/38 (21%) 17 2/17 (12%) 21 6/21(29%) NS

ENa First 64 56 14/56 (25%) 32 6/32 (19%) 24 8124 (33%) NS

Last 40 35 5135 (14%) 25 2/25 (8%) 10 3/10 (30%) NS

ALV First 64 41 lo/41 (24%) 24 4124 (17%) 17 6/17 (35%) NS

Last 40 20 2/20 (10%) 11 2/11 (18%) 9 O/9 NS

* Normal for this measurement refers to only one or neither value beingabnormal; abnormal refers to both values being abnormal.

NS = not significant; other abbreviations as in Table I.

40 I w---l

FKNJRE 6. Relation of the incidence of elevated LVIDd index to clinical congestive heart failure in patients with acute myocardial infarction. CHF = congestive heart failure; LVID,, = left ventricular internal dimension at end-diastole/body surface area.

evated in two and abnormal mitral valve closure in one.

Echocardiographic Measurements and Clinical Heart Failure

Figure 6 shows the significant (P <0.005) correlation between echocardiographic left ventricular size on the admission echocardiogram and clinical heart failure based on the Killip classification. However, 38 percent of patients (11 of 29) with a normal left ventricular internal dimension had clinical heart failure and 22 percent (7 of 32) with an elevated left ventricular internal dimension had no clinical evidence of

failure. There was also a significant correlation between an echocardiographically dilated left ventricle and the presence of either bilateral rales (P <0.005) or a third sound gallop (P <0.025).

There was no significant correlation between abnormal mitral valve closure and clinical heart failure or the presence of rales in this series of patients. There was a significant correlation between the presence of abnormal mitral valve closure and a third sound gallop (P <0.05).

Echocardiographic Measurements and Mortality

Results of the analysis of variables showing which echocardiographic findings might predict mortality are presented in Table II.

First echocardiogram: Although an echocardiographically dilated left ventricle and abnormal mitral valve closure were more common on admission among those who subsequently died, neither finding alone was useful in predicting mortality. Only when these two abnormalities were combined were they of significant value in predicting death (Fig. 7A). The mortality rate for the group in which both measurements could be made was 20 percent (9 of 46). The mortality rate among those in whom both variables were abnormal was 55 percent (6 of ll), whereas only 9 percent (3 of 35) of patients without this combina- tion died. This difference was significant (P <O.OOl). The LVIDd index/PR-AC ratio was also useful in predicting mortality (P <0.005) at the time of admission (Fig. 7B). The presence of abnormal wall motion was not useful for this purpose.

Last echocardiogram in the coronary care unit: Results of analyzing the same variables using each patient’s last echocardiogram obtained in the


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FIGURE 7. Correlation of incidence of hospital death in acute myocardiil infarction patients with: (A) abnormal mitral valve closure (reflecting an increased left ventricular end-diastolic pressure) plus an elevated LVtD,j index on the echocardiigram; (B) volume/pressure ratii estimated from the LVlDd index and the P&AC ratio; (C) the presence of normal or abnormal mitral valve closure. AC = mitral valve closure time interval from the echogram (seconds): LVIDd index = left ventricular internal dimension at enddiistole/bcdy surface area: PR = P-R interval from the electrocardiogram.

coronary care unit were different. Patients who had only one echocardiogram were excluded from this analysis. When these later echocardiograms were used, the presence of abnormal mitral valve closure alone was significant (P <0.005) in predicting mortality (Fig. 70. Most significant at this time was the LVIDd index/PR-AC ratio (P <O.OOOl) (Fig. 7B). Only 1 of 27 patients who had a volume/pressure ratio of less than 65 on his last echocardiogram died in the hospital, whereas 6 of 8 patients with values greater than 65 died before hospital discharge. Figure 8 shows the ratios for individual patients and indicates whether or not they died in the hospital. A value of 65 seemed to provide the separation of survivors and nonsurvivors. Abnormal wall motion was still not helpful in predicting mortality.

Clinical Findings and Mortality

Results of the analysis of clinical variables in predicting mortality are presented in Table III. There was significantly increased mortality in patients more than 60 years of age (P <0.025) and in those with a third sound gallop (P <0.05), rales (P <0.05) or clini-

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cal heart failure (Killip classification) on admission (P <0.05). Forty-eight hours after admission a third sound gallop was a better predictor of moitality (P <O.OOl) than either rales (P <O.Ol) or clinical heart failure on the basis of the Killip classification (P <O.Ol). Mortality was significantly different between patients in Killip class I (no heart failure) and those with class II heart failure (third sound gallop or bilateral rales, or both, without overt pulmonary edema or shock) at 48 hours (P <O.Ol) but not on admission.

Sequential changes: Although some daily changes in both the left ventricular internal diameter at end- diastole &VI&) index and the P-R minus mitral valve closure (PR-AC) interval were observed, the most striking sequential changes related to mortality were in the LVIDd index/PR-AC ratio as illustrated in Figure 9. For clarity, lines indicating change were drawn only for patients whose values went from the area of high mortality to that of low mortality or vice versa. The figure shows that abnormal echocardiographic findings preceded death by many hours or even days and were not due to sudden terminal events. There were three nonsurvivors with a “nor-

My 1975 The American Journal of CARDIOLOGY Volume 38 7

ECWCARDIOQRAPHY IN ACUTE iNFAFtCTON--COFtYA ET AL.

TABLE III

Analysis of Clinical Findings in Predicting Mortality in Atute Myocardial Infarction

3150 1- 80

100 -T O Patients Lived

00.) (no.)

49 Complete clinical profile obtained

Location of infarction Anterior wail Inferior wall Both

Age (yr) <60 260

Sex Male Female

SGOT 1250 units >250 units

On admission Killip class

I II III IV

S3 gallop present Bilateral rales present

At 48 hours Killip class

I II III IV

Sa gallop present Bilateral rales present

64

28 33 3

19 28 2

9.

5

I

NS 1

29 26 31 35 23 12i

(0.025

36 28 28 21

*’ NS 7i

35 29

29 20

6! NS

9)

27 24

31 22 4 2 2 1

20 12 36 24

3!NS 91 <0.05 2 1 8 <0.05

12 <0.05

21 39 0 0

15 39

21 01. 28 ll\

<O.Ol

7 8 <O.OOl

28 11 <O.Ol

Died

00.) P Value

Killip class: I = no heart failure; II = third sound gallop or bilateral rales, or both; III = pulmonary edema; IV = shock; SGOT = serum glutamic oxaloacetic transaminase; Sa = third heart sound.

ma1 volume/pressure ratio” in the admission echocardiogram whose ratio became abnormal before death and six of seven survivors with an abnormal ratio on admission whose ratio became normal while they were in the coronary care unit.

Discussion

Technical feasibility: This study demonstrates that technically adequate bedside echocardiograms can be obtained routinely in patients with acute myocardial infarction. Information about left ventricular wall motion and size was obtained on 59 of 64 patients (92 percent). Although mitral valve echoes were recorded on 61 of 64 cases (95 percent), a P-R minus mitral valve closure interval could be measured in only 47 of 61 patients (77 percent) because of atria1 fibrillation, heart block and sinus tachycardia in some patients and difficulty in accurately measuring the onset of the electrocardiographic P wave

1 0

95

90 *

e Last’ Echocardiogram Echocardiogram

n n n .

.

.O 0

FIGURE 8. Individual values for the echocardiographic volume/pressure ratio in patients with acute myocardial infarction. Sixty-five is the value that best separates the survivors from the nonsurvivors. Abbreviations as in Figure 7.

in others. With sinus tachycardia, the left ventricular filling period is often so short that the E and A points on the mitral valve echogram cannot be distin- guished.

Left ventricular wall motion: Echocardiography was a sensitive indicator in the early detection of abnormal areas of wall motion corresponding to the electrocardiographic site of transmural infarction in this study, but it is not possible to make a diagnosis of myocardial infarction from the echocardiogram. Abnormal motion is seen with chronic coronary artery disease without evidence of infarction,lp2 and it may be seen transiently during stress in patients who have normal echocardiographic motion at rest.lJ5 We have observed the same changes in patients with a diagnosis of preinfarction angina. The echocardiographic changes may be useful in determining whether symptoms are cardiac in origin when infarction has not taken place or before diagnostic electrocardiographic changes are present. Other conditions, in- cluding cardiomyopathy,16 left bundle branch block i7*ls right ventricular volume overload,1g~20 left ventricular volume overload21 and prosthetic valve


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Daily Changes In Survwors Dally Changes In Non-Survivors FIQURE 0. Sequential changes in the echocardiographb volume/pressure ratio in survivors (A) and nonsurvivors (B). For clarity, tines wwe only drawn for patients who change from areas of high mortality to low mortality, OT vice versa. Abbreviations as in Figure 7.

surgery,** affect echocardiographic motion and must also be considered.

Left ventricular internal dimension: Because the left ventricle may be asymmetrical in coronary artery disease, especially during contraction, caution must be exercised in using echocardiographic left ventricular dimensions to estimate volumes. Studies comparing volumes derived from biplane angiograms with those derived from single echocardiographic dimensions in patients with coronary artery disease support the use of a single left ventricular diastolic dimension for estimating diastolic volume.5 Although we found significant correlation between an increased left ventricular internal dimension and congestive heart failure, some patients with heart failure had a normal index (Fig. 6). Other investigators have also found a normal value for this dimension in patients with clinical signs of heart failure.23*24

Mitral valve closure: In a series of patients in whom the P-R minus mitral valve closure (PR-AC) interval was correlated with left ventricular pressure, it was found that when mitral valve closure was pro- longed enough to reduce the PR-AC interval to 0.06

second or less the left ventricular end-diastolic pressure was 20 mm Hg or greater with an “atria1 kick” of at least 8 mm Hg. l2 It is not certain that the correlation between valve motion and pressure demonstrated in patients with chronic disease is as reliable in patients with acute myocardial infarction and a wide range of P-R intervals.

We do not know how often decreased compliance was responsible for abnormal mitral valve closure. Presumably this was true in the patients with a left ventricle of normal size. There was no significant correlation between abnormal mitral valve closure and either increased left ventricular size or clinical heart failure based on the presence of rales or a third sound gallop, or both. However, abnormal mitral valve closure did correlate significantly with the presence of a third sound gallop. It is possible that increased left ventricular size with heart failure was also responsible for increased pressures in many cases.

Predicting mortality: Pulmonary arterial pressure, capillary wedge pressure and cardiac output have been useful in predicting mortality in patients with acute infarction.2527 Diamond and Forrester,zs

Jufy 1075 The Am&can Journal ol CARWOLOQY Vohmw 36 0

ECMDC~ M1 ACUTE iNFAi?CTIDN-CDRYA ET AL.

using left heart catheterization, have shown a high correlation between left ventricular compliance and prognosis in such patients. Investigation of left ventricular pressure-volume relation in these patients has been limited by the lack of an acceptable means of measuring left ventricular volume in acutely ill persons. Recently Smith et a1.24 studied the volume- pressure relation (“compliance”) in 14 patients with acute myocardial infarction. They used the pulmonary arterial end-diastolic pressure as the left ventricular filling pressure and echocardiographic dimensions to determine left ventricular volumes. The sequential compliance values were more useful than either left ventricular filling pressure or left ventricular volume in predicting survival in that study.

We do not know how well our echocardiographic volume/pressure ratio represents compliance but our results show that it may be useful in predicting mortality and in following a patient’s clinical course. It is also unknown whether the combined presence of ab-

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normal mitral valve closure and an increased left ventricular internal dimension at end-diastole on admission, which was highly significant in predicting mortality, represents predominantly decreased compliance or heart failure.

Clinical implications: This study does not prove that the echocardiogram accurately reflects left ventricular volume and end-diastolic pressure. These as- sumptions are based on previous studies in patients with chronic disease. This study does demonstrate: (11 technically adequate echocardiograms can be obtained in most patients with acute infarction. (2) Echocardiography is a sensitive method of detecting abnormalities of left ventricular wall motion corresponding to the electrocardiographic site of infarction. (3) An echocardiographically dilated left ventricle usually indicates congestive heart failure. (4) Echocardiographic measurements and their relation to each other are useful in determining prognosis in individual patients.

References

Jacobs JJ, Feigenbaum H, Corya BC, et al: Detection of left ventricular asynergy by echocardiography. Circulation 48:263- 271, 1973 Corya BC, Feigenbaum H, Rasmussen S, et al: Anterior left ventricular wail echoes in coronary artery disease. Am J Cardiol 34652-657, 1974 Brown OR, Popp RL, Harrison DC: Abnormal interventricular septal motion in patients with significant disease of the left anterior descending coronary artery or other conditions of septal faiiure (abstr). Am J Cardiol 3 1: 123, 1973 Ludbreok P, Kariiner JS, Peterson K, et al: Comparison of ultrasound and cineangiographic measurements of left ventricular performance in patients with and without wail motion abnormalities. Br Heart J 351026-1032. 1973 Ratahln RA, Rackiey CE. Russell RO Jr, et al: Quantitative echocardiography: correlations with calculated ventricular volumes and wail thickness by quantitative angiography in selected patient subsets (abstr). Clin Res 21:444, 1973 Tekhhoit LE, Kreuien TH, Herman MV, et al: Problems in echocardiographic volume determinations: echo-angiographic correlations (abstr). Circulation 45, 46:Suppl ll:ll-75, 1972 Stefan G, Bing RJ: Echocardiographic findings in experimental myocardial infarction of the posterior left ventricular wall. Am J Cardioi 30:629-639, 1972 Kerber RE, Abboud FNI: Echocardiographic detection of region- al myocardial infarction. Circulation 47:997-1005, 1973 Raiahin RA, Rackiey CE, Ruaaeii RO Jr: Serial evaluation of left ventricular volumes and posterior wall movement in the acute phase of myocardial infarction using diagnostic ultrasound (abstr). Am J Cardiol 29:266, 1972 Pombo JF, Russell RO, Rackiey CE, et al: Comparison of stroke volume and cardiac output determination by ultrasound and dye dilution in acute myocardial infarction. Am J Cardiol 27: 630-635, 197 1 Feigenbaum H: Echocardiography. Philadelphia, Lea 8 Febiger, 1972, p 37-41 Konecke LL, Feigenbaum H, Chang S, et al: Abnormal mitral valve motion in patients with elevated left ventricular diastolic pressures. Circulation 47:969-996, 1973 Zaky A, Steinmetz E, Feigenbaum H: Role of atrium in closure of mitral valve in man. Am J Physiol 217:1652-1659, 1969 Shah PM, Kramer DH, Gramiak R: influence of the timing of

July 1975 The Amerkan Journal of CARDIOLOGY Volume 36

15.

16.

17.

18.

19.

20.

21. 22. 23.

24.

25.

26.

27.

26.

atrial systoie on mitral valve closure and on the first heart sound in man. Am J Cardiol 26:231-237, 1970 Widianaky S, McHenry P, Corya BC, et al: Coronary angiographic, echocardiographic and electrocardiographic studies on a patient with variant angina due to coronary artery spasm. Am Heart J, in press Corya BC, Feigenbaum H, Rasmussen S, et al: Echocardio- graphic features of congestive cardiomyopathy compared with normal subjects and patients with coronary artery disease. Cir- culation 49:1153-l 159, 1974 McDonald IC: Echocardiographic demonstration of abnormal motion of the interventricular septum in left bundle branch block. Circulation 46:272-260, 1973 Dillon JC, Chang S, Feigenbaum H: Echocardiographic mani- festations of left bundle branch block. Circulation 49:676-660, 1974 Diamond MA, Dillon JC, Haine CL, et al: Echocardiographic features of atriai septal defect. Circulation 43:129-135. 1971 Hagan AD, Francis OS, Sahn DJ, et al: Ultrasound evaluation of systolic anterior septal motion in patients with and without right ventricular volume overload. Circulation 50:246-254, 1974 Feigenbaum H: Ref 11, p 122 Ibid, p 123-124 Broder MI, Cohn JN: Evolution of abnormalities in left ventricular function after acute myocardial infarction. Circuiation 46: 731-743, 1972 Smith M, Ratshin RA, Harreli FE, et al: Early sequential changes in left ventricular dimensions and filling pressure in patients after myocardial infarction. Am J Cardiol 33:363-369, 1974 Rutherford BD, McCann WD, O’Donovan TPB: The value of monitoring pulmonary artery pressure for early detection of left ventricular failure following myocardiil infarction. Circulation 43~655-666. 1971 Hanrath P, Bieiteid W, Mathey D, et al: Acute myocardial infarction. Dtsch Med Wochenschr 99:219-226. 1974 Rat&in RA, Rackiey CE, Ruaaeii RO Jr: Hemoclynamic evaluation of left ventricular function in shock complicating myocardial infarction. Circulation 45:127-139, 1972 Diamond G, Forreater JS: Effect of coronary artery disease and acute myocardial infarction on left ventricular compliance in man. Circulation 45:l l-19. 1972

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