doppler echocardiography during pregnancy : physiological and abnormal findings

Doppler Echocardiography During Pregnancy: Physiological and Abnormal Findings

ORLANDO CAMPOS, M.D. Department of Cardiology, Escola Paulista de Medicina, Sao Paulo, Brazil

Despite continuous improvements in diagnostic cardiology techniques, echocardiography remains the cornerstone for noninvasive cardiovascular assessment of the pregnant woman with heart disease or suspected cardiac abnormality. Reversible physiological cardiac remodeling of pregnancy associated with changes in valve patency or transvalvular flow pattern can be suitably assessed by the comple- mentary use of quantitative pulsed- and continuous Doppler and qualitative color Doppler technology. These techniques are also useful for a better understanding of the pathophysiology of the hemodynamic consequences of fixed valve stenosis during pregnancy with respect to the labile nature of gradients resulting from variable loading conditions as occurs during pregnancy. Recent and specific areas of clinical use including cardiac output estimation, contrast echocardiography minimizing radioscopy during cardiac catheterization, and transesophageal echocardiography for selection of patients with mitral stenosis suitable for percutaneous catheter valvotomy illustrate the large spectrum of capabilities of this versatile method during pregnancy. (ECHOCARDIOGRAP~, Volume 13, March 1996)

Doppler echocardiography, pregnancy, physiology, heart disease

The physiological volumetric overload of pregnancy associated with a hyperkinetic state represents an adaptation process of the cardiovascular system induced by increased meta- bolic demand of the fetus. While this circula- tory burden is usually well tolerated by the normal pregnant woman, it may constitute an unstable condition for a woman with preexist- ing overt heart disease, leading to higher mor- bidity/mortality rates for mother and fetus.' Successful management involves knowledge of these physiological adjustments that may cause peculiar signals mimicking heart disease, which may sometimes interfere with laboratory examination results and lead to misdiagnosis.'

Comprehensive assessment of the anatomical and functional aspects of the heart during pregnancy can be performed by Doppler echocardiography (echo) without demonstrable

Address for correspondence and reprints: Orlando Cam- pos, M.D., Escola Paulista de Medicina, Rua Madre Cabrini 332 ap 22, 04020.001, Sao Paulo, Brazil. Fax: 55- 11-5710047.

harm to mother or fetus. Because of the ad- vantages of its safety, reproducibility, and practicality, Doppler echo techniques represent a powerful, valuable, and unique tool for cardiovascular diagnosis during pregnancy.

In the past two decades, Doppler echo has been used not only for physiological investiga- tion1.15 but also to obtain evidence of heart disease and to exclude cardiac abnormalities when a murmur is detected in an asymptomatic pregnant woman. In this article, we will review and discuss some of the clinical aspects of echo during pregnancy, focusing mainly on Doppler techniques, stressing its usefulness in the management of cardiac problems and pre- senting our experience in this area.

Physiological Aspects

Structural Changes

The anatomical cardiac modifications that take place during pregnancy have been well established by longitudinal3-" and nonlongitudi-

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TABLE I

Cardiac Chamber Dimensions During Normal Pregnancy and Puerperium

Pregnant Women (n = 18) Control

T1 T2 T3 T4 T5 (n = 18)

LV (mm) 41.4 t 3.1 42.7 t 2.2" 43.0 t 1.7* 43.6 i 2.5* 41.8 t 1.8 40.1 t 3.0 LA (mm) 29.6 t 2.1 31.5 t 2.4* 33.1 t 2.4* 32.8 t 3.0* 29.9 t 3.1 27.9 t 2.47 RV (mm) 30.1 t 2.0 31.9 5 2.1 35.5 t 3.2*# 35.5 t 2.3*# 31.1 t 2.1 28.5 t 3.0 RA (mm) 42.8 f 2.3 47.4 rt 2.4* 50.8 L 2.7*# 50.9 5 2.8*# 46.6 5 3.3* 43.7 5 4.4

Control = nonpregnant women; LA 8th-12th week of pregnancy; T2 =

Values > T1, P < 0.05. #Values Cardiol.)

= left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle; T I = 20th-24th week; T3 = 30th-34th week; T4 = 36th40th week T5 = puerperium. > T2, P < 0.05; ?Values < TI, P < 0.05. (Reproduced with permission from Int J

nal studies11-16 using M-mode and two-dimensional echo. They reported slight but significant increases in the dimensions of the four cardiac chambers beginning with pregnancy, evolving in a gradual fashion until puerperium as an expression of transient hypervolemia and physiological diastolic overload. We prospectively analyzed changes in cardiac dimensions in 18 healthy women during their pregnan~ies,~JO and the results are shown in Table I. A progressive rise in cardiac chamber dimensions, except for the aortic root, was observed. At term, an average increase of 19% for right atrium, 18% for right ventricle, 12% for left atrium, and 6% for left ventricle as compared with initial values from early pregnancy were noted. Although significant, these changes were not clinically relevant as they were limited to the upper normal values of nonpregnant women.

Despite mild cardiac dilatation in pregnancy, myocardial thickness remains un- changed, resulting in increased myocardial mass as assessed by M-mode measurement^.^^^ This eccentric hypertrophy occurs in an at- tempt to decrease systolic wall tension and to preserve myocardial contractility against a sustained augmentation of p r e l ~ a d . ~ , ~

Structural cardiac changes during pregnancy are not confined to the atrial or ventricular chambers and ventricular myocardium, but also involve the valve annuli dimensions. In our longitudinal study,1° we observed early and progressive dilatation of pulmonary, tricuspid, and mitral valve annuli corresponding to 28%) 14%, and 8% of increase in late pregnancy, respectively, compared to initial values (Table 11)) confirming findings from other au- t h o r ~ . ~ J ~ J ~ Annular diameters increased pre- dominantly in right-sided valves in a similar

TABLE I1

Valve Annular Diameters in Normal Pregnancy and Puerperium


T1 T2 T3 T4 T5 (n = 18)

Mi (mm) 22.5 L 1.5 22.8 f 0.9 23.8 t 1.1*# 24.0 L 1.2*# 22.5 t 1.0 20.0 t 1.4t Tr (mm) 22.1 5 1.7 23.1 t 1.0 24.7 2 1.3*# 24.6 5 1.1*# 22.3 t 1.3 20.0 f 1.5? Pu (mm) 19.6 t 1.8 22.1 t 1.7* 23.9 L 1.5*# 25.3 f 2.3*# 22.9 t 2.1* 20.8 t 2.1 Ao (mm) 18.1 L 0.9 17.5 2 0.8 18.0 t 0.7 18.2 t 0.6 18.3 t 0.7 17.8 t 1.1

Ao = aortic; Control = nonpregnant women; Mi = mitral; Pu = pulmonary; Tr = tricuspid; Tl-T4 = periods of pregnancy (see Table I); T5 = puerperium. *Values > T1, P < 0.05. #Values > T2, P < 0.05. ?Values < T1, P < 0.05. (Reproduced with permission from Int J Cardiol.)

136 ECHOCARDIOGRAPHY: A Jrnl. of CV Ultrasound & Allied Tech. Vol. 13, No. 2,1996

DOPPLER ECHOCARDIOGRAPHY DURING PREGNANCY

fashion as occurred with right-sided chamber dilatation. There were no substantial differences in aortic annular diameter, confirming the stability of this structure during pregnancy as observed by others.Z,6,16

Valve Function Valve function during pregnancy as as-

sessed by Doppler techniques may be influ- enced by the anatomical process of adaptation. In the same study using pulsed and continuous Doppler," we observed a significant and progressive rise in the prevalence of physiological tricuspid and pulmonary trivial regurgitation, and a transient development of trivial mitral regurgitation during pregnancy (Fig. 1). Aortic regurgitation was not detected during any stage of pregnancy or puerperium. Increased prevalence of tricuspid regurgitation during late pregnancy related to annular dilatation was first reported by Limacher et al.I3 using the pulsed-Doppler technique. Sadaniantz et a1.,I6 using color Doppler echo in a nonlongitudinal study of older pregnant women with higher body surface area, did not demonstrate higher rates of tricuspid or mitral valve regurgitation in late pregnancy despite increases of atrioventricular valve rings. Differences in study design or variable modal-

1OO%(I

80%

60%

40%

20%

T1 T2 T3 T4 T5 control

Figure 1. Prevalence of physiological valvular regurgitation during pregnancy (T1 to T4, see Table I) and puerperium (T51, according to each valve affected, (Reproduced with permission from Int J Car- diol.)

ities of Doppler echo techniques between the two studies may account for these apparent discrepancies.

It seems that the increased prevalence in multivalvular physiological regurgitation during normal pregnancy could be due to functional annular dilatation that accompa- nies chamber enlargement,13 with a reduced effectiveness in leaflet coaptation." Predomi- nance of right-sided valvular regurgitation during pregnancy could be explained by structural characteristics, where a more elastic and compliant annulus of the tricuspid or pulmonary valve would lead to an increased sus- ceptibility to dilatation. The more dense and rigid fibrous texture of the aortic ring could explain the absence of dilatation and aortic regurgitation during normal pregnancy.1° In- creased occurrence of physiological valvar regurgitation in women may also be present in other forms of cardiac remodeling related to physiological loading conditions, as occurs during continuous physical exercise in nonpregnant ~ o m e n . ' ~ - ~ ~

In summary, chamber enlargement and valve annuli dilatation in normal pregnant women represent a reversible remodeling process induced by physiological volume overload, which are accompanied by increased rates of trivial, functional multivalvular regurgitation, mainly in right-sided valves during late stages of pregnancy. These normal findings should be considered when interpret- ing the Doppler echo of a pregnant woman in order to avoid an incorrect diagnosis of valve dysfunction.

Systolic Function

Systolic function during pregnancy evalu- ated by systolic indices of ventricular performance (fractional shortening and ejection fraction) is described by some authors as being in- creasedsall and by others as remaining table.^^^,^ The influence of multiple factors in ventricular performance during pregnancy (increased venous return and reduced peripheral vascular resistance), as well as methodological differences, may account for some controversies in this issue. In the third trimester of pregnancy,


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for example, the hemodynamic effects of the enlarged uterus must be considered. Inferior vena cava compression may decrease preload, resulting in diminished ventricular filling with potential influence in systolic indices assessed by echo.

Diastolic Function

Changes in left ventricular filling parameters during late pregnancy were described in a recent study demonstrating an increase in the A wave of the mitral valve pulsed-Doppler curve associated with a dilated left atrium.I6 It was speculated that a Frank-Starling mecha- nism of the left atrium could be working to augment stroke volume by increasing its con- tribution to left ventricular filling. Other Doppler-derived indexes of diastolic function, such as pressure half-time, deceleration time, and isovolumic relaxation time interval, were not reported in that article. Because of alter- ations in heart rate, loading conditions, and annular diameters that take place during pregnancy, the influence of the pregnant state on the diastolic properties of the heart are not yet definitively established.

Cardiac Output Assessment

The capability to noninvasively estimate cardiac output by Doppler echo stimulated the extension of this technique to the evaluation of pregnant women. Several studies have demonstrated gradual augmentation of cardiac output during evolution of normal pregnancy and puerperium, increasing 30%-50% during the

final ~ t a g e s . ~ - ~ J ~ , ~ ~ - ~ ~ Stroke volume was derived from left ventricular outflow area and pulsed- Doppler systolic time-velocity integral obtained at the same level, or by using suprasternal and apical continuous Doppler curves with aortic root area measured by A- mode or M-mode echo. These methods were able to detect acute changes in cardiac output induced by Cesarean or by modifications in the pregnant woman's posture: supine position induced a 5% reduction in stroke volume caused by a decrease in venous return because of inferior vena cava compression by the dilated uterus.7,21*22 Serial measurements of cardiac output by Doppler echo techniques during pregnancy demonstrated high coeffi- cients of correlation when compared to stan- dard noninva~ive'~ or invasive techniquesz4 with acceptable intraobserver ~ariabi1ity.I~ Al- though individual variations of absolute values of cardiac output represent a limitation of Doppler echo techniques, the method is partic- ularly suitable to detect relative changes of this parameter.8~20~22 The behavior of cardiac output during normal pregnancy is shown in Table 111.

As a result of the high cardiac output during pregnancy, higher transvalvular flow velocities can be observed, mainly in semilunar valve^.^,^^ Table I11 also shows our results of aortic peak flow velocities obtained by continuous-wave Doppler in 18 normal pregnant women. Com- pared with puerperium, there was an early, mild, but significant increase of 10% in aortic peak velocities with maximal values of 20% of increase during late pregnancy.

TABLE I11

Evolution of Cardiac Output and Transaortic Peak Flow Velocity During Normal Pregnancy and Puerperium ~ ~ ~~ ~~ ~


T1 T2 T3 T4 T5 (n = 18)

Cardiac output (L/min) 3.6 ? 0.6* 4.3 2 0.5*T 4.5 t 0.8*t 4.4 t 0.9*t 2.9 i 0.4 3.4 2 0.8 Aortic peak flow

velocity (m/s) 1.20 2 0.11* 1.25 t 0.09* 1.31? 0.12*t 1.332 0.14*t 1.09 2 0.13 1.08 t 0.14

Control = nonpregnant women; Tl-T4 = periods of pregnancy (see Table I); T5 = puerperium; values expressed as mean i 1SD. *Values > T5, P < 0.05; tvalues > T1, P < 0.05.

138 ECHOCARDIOGWW. A Jrnl. of CV Ultrasound & Allied Tech. Vol. 13, No. 2,1996


Role of Doppler Echo in Heart Disease and Pregnancy

Assessment of Native Valve Dysfunction The knowledge based on Doppler echo find-

ings that transvalvular flow increases during pregnancy is helpful in understanding the hemodynamic worsening of stenotic valvar lesions of pregnant women. As transvalvular gradients are determined by valve area and flow velocity, a mild increase of flow velocities across a fixed stenosis impinges a substantial rise in pressure gradients. Therefore, because of the high flow state of pregnancy, there is a potential risk of overestimation of stenotic lesions based solely on pressure gradients.

These aspects of pregnancy can be expressed mainly by mitral stenosis. This lesion, as one of the most frequent valvular diseases in young women, represents a troublesome situation during pregnancy. In these circumstances, there is a progressive rise in left atrial pressure caused by hypervolemia and tachycardia. A shortened diastolic period makes left atrial emptying difficult, which contributes to an increase in venocapillary and pulmonary pressures. As a result, even moderate mitral stenosis may worsen as pregnancy evolves, with se-

vere symptomatic pulmonary and systemic congestion, Objective monitoring of these hemodynamic parameters can be obtained by serial Doppler echo examinations, which can demonstrate a progressive increase in transmi- tral pressure gradient with maximal values during the third t r i rne~ter .~~J~ We observed some differences in the hemodynamic behavior of mitral stenosis during pregnancy in six women undergoing digitalis, diuretic, and beta-blocker therapy, depending on the Doppler-derived mitral valve area (Table IV). In mild-to-moderate lesions (mean valve area 1.4 cm2), pregnancy produced no relevant effects in mean diastolic gradient or systolic pulmonary artery pressure. In contrast, in severe lesions (mean valve area 1.0 cmz), despite sta- ble heart rates, there was a substantial rise in mean diastolic gradient as well as systolic pulmonary pressure (Fig. 21, both decreasing after delivery. Because pressure half-time may be altered during late pregnancy in severe cases of mitral stenosis,27 the Doppler echo continuity equation method may be a more suitable al- ternative for estimating mitral valve area in these circumstances.

Aortic stenosis, although relatively uncom- mon during pregnancy, may also be affected by

TABLE IV Doppler Echocardiographic Variables in Mitral Stenosis During

Pregnancy and Puerperium, According to the Valve Area

Heart Mean Systolic Left Rate MVA Gradient PAP Atrium (bpm) (ern') (mmHg) (mmHg) (mm)

Moderate (n = 3) T1 79 1.60 T2 85 1.55 T3 78 1.52 T4 74 1.41 T5 66 1.55

T1 87 1.06 T2 80 0.90 T3 82 0.98 T4 85 0.86 T5 50 0.85

Severe (n = 3)

7 8 9

10 7

15 17 22 20 10

41 45 37 42 30

64 70 80 89 48

48 50 49 52 50

55 51 52 54 53

MVA = mitral valve area; PAP = pulmonary artery pressure; T1-T4 = periods of pregnancy (see Table I); T5 = puerperium. Values expressed by means.


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Figure 2. Evolutionary pattern of mitral diastolic gradient (top) and systolic artery pressure (bottom) in a woman with severe rnitral stenosis at 3 months (left) and 8 months (right) of pregnancy, derived from continuous Doppler curves of mitral and tricuspid valves. I n the rnitral valve, diastolic peak gradient increased from 25 to 33 rnmHg; in the tricuspid valve, systolic peak gradient rose from 27 to 78 mmHg.

increased cardiac output, resulting in overestimation of systolic pressure gradients. The evolutionary changes in aortic peak flow gradients during pregnancy were described in a 24-year- old woman with a dysfunctional aortic bioprosthesis, demonstrating the flow dependence of this parameter.28 The following values were observed: 10th week: 74 mmHg; 24th and 32nd weeks: 92 mmHg; 38th week: 88 mmHg; and 6th week postpartum: 64 mmHg. The comple- mentary use of aortic valve area derived noninvasively from the Doppler echo continuity equation may circumvent this problem. Aortic valve area and systolic peak flow gradients were determined in a study of four pregnant women with aortic stenosisZ9 and fetuses of dif- ferent gestational ages with the following results: 1.9 cm2 (46 mmHg); 0.8 cm2 (85 mmHg); 0.7 cm2 (58 mmHg); and 0.4 cm2 (164 mmHg). The importance of identifying “pseudocritical aortic stenosis” was stressed in a case report of an asymptomatic pregnant woman in labor with a peak flow gradient of 104 mmHg.30 An aortic valve area estimated by Doppler echo at

1.8 cm2 excluded severe aortic stenosis, similar to the value of 1.6 cm2 obtained by the Gorlin formula with invasive technique. The usefulness of pre- and postoperative Doppler-derived aortic valve area is shown in Figures 3 and 4.

Evaluation of Prosthetic Dysfunction

In Brazil, there has been an increasing num- ber of pregnancies in young women who had mechanical or biological prostheses inserted due to rheumatic fever.31 Risk of tissue valve de- generation or mechanical prosthetic thrombosis seems to increase during p regnanc~ .~~ A se- verely calcified bioprosthesis may produce clinical consequences resembling native valve dysfunction (Fig. 5) . At term, substitution of oral anticoagulation for intravenous or subcuta- neous heparin represents a very difficult matter in pregnancy and is not without risk of disc t h r o m b ~ s i s . ~ ~ - ~ ~ Identification of clots by means of transthoracic echo may be difficult with mechanical prostheses because of artifacts gener- ated from metallic components, even in cases of



Figure 3. Preoperative Doppler echo of a symptomatic woman with rheumatic aortic and mitral stenosis at 29 weeks of pregnancy. Top: long- and short-axis views from the aortic value showing commissural fusion. Bottom: M-mode echo depicting leaflet thickening. Continuous Doppler of aortic valve revealed a systolic peak gradient of 68 mmHg. Valve area estimation was 0.76 cmz for the aortic valve and 1.1 cm2 for mitral value. Ao = aorta.

Figure 4. Postoperative findings of the same case shown in Figure 3. One week after successful aortic and mitral commissurotomy, at 32 weeks of pregnancy, a wide opening of both aortic (top) and mitral (bottom) valves can be seen. Aortic peak systolic gradient decreased to 39 mmHg, and aortic valve area increased to 1.2 cm'. Mitral value area increased to 2.0 cm2.

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Figure 5. A case of a dysfunctional aortic bioprosthesis and left ventricular dysfunction 6 years after cardiac surgery in a 34-year-old woman at 3 months ofpregnancy, in New York Heart As- sociation Functional Class III. Bottom: long- and short-axis views of a stenotic, heavy calcified bioprosthesis with a systolic peak gradient of 63 mmHg and a significantly narrowed valve area of 0.5 cm2. Ao = aorta.

massive thrombosis. A large thrombus on the ventricular surface of a dysfunctioning Bjork- Shiley mitral prosthesis was recognized by transthoracic echo in a 38-week pregnant woman and confirmed at surgery performed im- mediately after emergency Cesarean section.33 When thrombus is located on the atrial surface of the mitral prosthesis, transesophageal echo may be helpful in recognizing this abnormality. In general, prosthetic dysfunction induced by thrombosis may be diagnosed mainly by indi- rect signals suggesting an obstructed mitral ori- fice (limited disc motion, eccentric jet with high velocity turbulent flow, elevated mean diastolic gradients with prolonged pressure half-time, and pulmonary hypertension with right-sided chamber dilatation), when emergency surgery may be performed on a clinical basis without invasive ~ t u d i e s . ~ ~ , ~ ~ Alternatively, thrombolytic therapy for critically ill pregnant women with aortic valve thrombosis has recently been docu- mented by serial Doppler echo studies with no reports of bleeding complications for mother and fetus.35

Selection of Candidates Suitable for Balloon Valvotomy

In selected symptomatic pregnant women with moderate or severe mitral stenosis, percutaneous balloon valvotomy represents an ef- fective therapeutic procedure to improve hemodynamic status, relieve symptoms, and pro- mote clinical ~ t ab i l i t y .~~ This approach seem to carry a more favorable outcome to the fetus, with apparently less risk for fetal loss when compared to conventional open heart surgery under bypass performed after the first trimester of pregnancy. Usually, transthoracic Doppler echo provides sufficient data for se- lecting eligible candidates and may play a role in guiding transseptal puncture when diff- culty occurs during the procedure (Fig. 6). Ac- cording to our experience, when thrombus ex- istence is doubtful by transthoracic echo, transesophageal access can be performed safely with local anesthesia and mild sedation with low dose intravenous midazolam without hazard to mother or fetus (Fig. 7).



Figure 6. Subcostal approach to the heart in a symptomatic pregnant woman with mitral stenosis during balloon mitral ualuotomy. Top: four-chamber view shows the balloon catheter located in the left atrium (LA), after traversing the interatrial septum, resulting in a mild defect at this level (arrow in bottom panel). RA = right atrium.

Guidance of Cardiac Catheterization

Doppler echo often can eliminate the need for cardiac catheterization in pregnant women with valvular or congenital lesions. However, in some instances, direct assessment of intracardiac pressures o r coronary anatomy demands invasive studies. Contrast echo may be useful to investigate valve regurgitation or intracardiac and may be a reliable tool in pregnant women to avoid or minimize irradiation exposure deleterious to the fetus.38 Other clinical applications of Doppler echo in this setting include orienta- tion of catheter positioning for transseptal puncture in balloon mitral valvotomy as men- tioned previously (Fig. 61, controlling perma-

Figure 7. Transesophageal horizontal plane at the level of the left atrium (LA) from a young pregnant woman with mitral stenosis and atrial fibrillation. After excluding left atrial or left atrial appendage (LAE) thrombosis, balloon mitral valvotomy was performed without complications. A 0 = aorta; RA = right atrium.

nent ventricular pacemaker insertion,39 and during diagnostic or therapeutic electrophysi- ological p r o c e d ~ r e s . ~ ~ ~ ~ ~

Measurements of Cardiac Output and Ventricular Performance in Heart Disease

A potential value of cardiac output determination by Doppler echo is the serial monitoring of maternal hemodynamics in high risk obstet- rical patients near partum, not only when heart disease is present, but also in other pathological conditions such as pregnancy-induced hypertension, eclampsia, or hemorrhagic shock, where invasive cardiocirculatory assessment would otherwise be n e c e ~ s a r y . ~ ~ , ~ ~ Specific situations for the use of noninvasive Doppler echo techniques are represented by the critically ill pregnant patient with limita- tions to the thermodilution technique as it occurs in coagulopathies with hemorrhagic states or significant tricuspid regurgitati~n.~~ The applicability of this technique in clinical decision making is seen in a case of a 29-year- old woman with a 24-week pregnancy who pre- sented with mildly symptomatic atrial tachycardia of 140 beatdmin. Doppler echo revealed

Vol. 13, No. 2, 1996 ECHOCARDIOGRAPHY: A Jrnl. of CV Ultrasound & Allied Tech. 143

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Figure 8. Doppler echo before (top) and after (bottom) recouery of sinus rhythm in a pregnant woman with atrial tachycardia and mild left ventricular dysfunction (see text for details). Suprasternal continuous Doppler curues from the aortic valve and M-mode tracings from left ventricle are shown.

diffuse hypokinesis with an ejection fraction of 0.46 and cardiac output of 3.3 L/min. Immedi- ate antiarrhythmic treatment was performed with successful sinus rhythm recovery to 88 beatdmin. Although Doppler echo revealed only a mild increase in ejection fraction (0.52), an evident hemodynamic improvement could be characterized by a cardiac output increase to 5.0 Umin (Fig. 8).

Depressed systolic function in pregnant women with cardiomyopathy can easily be recognized by Doppler echo with therapeutic im- pl icat ion~.~~ The prognostic value of M-mode echo measurement in postpartum cardiomyopathy was demonstrated in our in~ t i tu t ion .~~ According to this study, among clinical, elec- trocardiographic, radiologic, hemodynamic, and endomyocardial biopsy findings, only an initial left ventricular diastolic diameter 5 55 mm could predict a favorable late outcome with clinical improvement and functional ventricular recovery. In contrast, left ventricular diameter 2 69 mm was present in those who did poorly after a mean period of 17 months of follow-up.

Conclusions

Doppler echo provides an objective, comprehensive, and noninvasive tool for maternal cardiac evaluation during pregnancy in physiological or abnormal states. Rational determination of valvular and ventricular functions during pregnancy can easily be obtained by dif- ferent modalities of Doppler echo, contributing to better medical treatment for the mother with suspected or confirmed heart disease.

Acknowledgments: The author acknowledges Dr. Jose L. Andrade and Dr. Antonio C. Carvalho for reviewing the manuscript.

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doppler echocardiography during pregnancy : physiological and abnormal findings

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