Scholarly article on topic 'Tissue Doppler assessment of left ventricular diastolic function in rheumatic mitral stenosis'

Tissue Doppler assessment of left ventricular diastolic function in rheumatic mitral stenosis Academic research paper on "Clinical medicine"

CC BY-NC-ND
0
0
Share paper
Academic journal
The Egyptian Heart Journal
OECD Field of science
Keywords
{"Mitral stenosis" / "Pulsed TDI" / "LV diastolic function"}

Abstract of research paper on Clinical medicine, author of scientific article — Maged Z. Amer, Ayman A. Abd-Alaziz

Abstract Background Left ventricular systolic and diastolic functions are reported to be altered in mitral stenosis. Although conventional Doppler ultrasound recording of transmitral flow is used in the assessment of left ventricular diastolic function, yet, in patients with mitral stenosis, it is altered by mitral stenosis itself and thus precludes the proper assessment of LV diastolic function. Aim of the work The aim of this work is to assess LV diastolic function using pulsed tissue Doppler interrogation of mitral annulus motion in patients with rheumatic mitral stenosis. Patients and methods Twelve patients with established diagnosis of rheumatic mitral stenosis in normal sinus rhythm were obtained from outpatient clinic of Cardiology Department in Mansura specialized hospital. Thirteen age and sex matched controls with completely normal echo-Doppler study were taken for comparison. All patients were subjected to thorough history taking including dyspnea grading according to NYHA score, clinical examination, 12 lead surface electrocardiogram and most importantly echo-Doppler study. Results We found statistically significant higher peak mitral annular E a velocity from septal, anterior, inferior and lateral portions of the mitral annulus in controls compared with mitral stenosis patients as well as their averaged values. There is no statistically significant difference regarding peak mitral annular A a velocity from septal, anterior, inferior and lateral portions of the mitral annulus between both groups as well as their averaged values. The ratio of early to late mitral annular velocities from all recorded sites was statistically significantly higher in the controls compared with mitral stenosis patients. Conclusions TDI of mitral annulus may provide potential diagnostic role for assessment of LV diastolic function in patients with mitral stenosis.

Academic research paper on topic "Tissue Doppler assessment of left ventricular diastolic function in rheumatic mitral stenosis"

The Egyptian Heart Journal (2011) 63, 161-167

Egyptian Society of Cardiology The Egyptian Heart Journal

www.elsevier.com/locate/ehj www.sciencedirect.com

ORIGINAL ARTICLE

Tissue Doppler assessment of left ventricular diastolic function in rheumatic mitral stenosis

Maged Z. Amer *, Ayman A. Abd-Alaziz

Cardiology Department, Mansoura University, Dakahlia, Mansura 35511, Egypt

Received 21 February 2011; accepted 26 March 2011 Available online 29 November 2011

KEYWORDS

Mitral stenosis; Pulsed TDI; LV diastolic function

Abstract Background: Left ventricular systolic and diastolic functions are reported to be altered in mitral stenosis. Although conventional Doppler ultrasound recording of transmitral flow is used in the assessment of left ventricular diastolic function, yet, in patients with mitral stenosis, it is altered by mitral stenosis itself and thus precludes the proper assessment of LV diastolic function. Aim of the work: The aim of this work is to assess LV diastolic function using pulsed tissue Doppler interrogation of mitral annulus motion in patients with rheumatic mitral stenosis. Patients and methods: Twelve patients with established diagnosis of rheumatic mitral stenosis in normal sinus rhythm were obtained from outpatient clinic of Cardiology Department in Mansura specialized hospital. Thirteen age and sex matched controls with completely normal echo-Doppler study were taken for comparison. All patients were subjected to thorough history taking including dyspnea grading according to NYHA score, clinical examination, 12 lead surface electrocardiogram and most importantly echo-Doppler study.

Results: We found statistically significant higher peak mitral annular Ea velocity from septal, anterior, inferior and lateral portions of the mitral annulus in controls compared with mitral stenosis patients as well as their averaged values. There is no statistically significant difference regarding peak mitral annular Aa velocity from septal, anterior, inferior and lateral portions of the mitral annulus between both groups as well as their averaged values. The ratio of early to late mitral annular velocities from all recorded sites was statistically significantly higher in the controls compared with mitral stenosis patients.

Corresponding author. Tel.: +20 502224555; mobile: +20 106724660; fax: +20 502248203, +20 502260138, +20 502235069. E-mail address: magedzag@yahoo.com (M.Z. Amer).

1110-2608 © 2011 Egyptian Society of Cardiology. Production and hosting by Elsevier B.V. All rights reserved.

Peer review under responsibility of Egyptian Society of Cardiology. doi:10.1016/j.ehj.2011.08.035

Conclusions: TDI of mitral annulus may provide potential diagnostic role for assessment of LV diastolic function in patients with mitral stenosis.

© 2011 Egyptian Society of Cardiology. Production and hosting by Elsevier B.V. All rights reserved.

1. Introduction

Rheumatic mitral stenosis is relatively endemic in developing countries including Egypt. Many cases with mitral stenosis have pulmonary congestive symptoms out of proportion to the physical obstruction to left atrial emptying imposed by the stenotic mitral valve.1 Left ventricular systolic and diastolic functions are reported to be altered in mitral stenosis.2 Conventional Doppler ultrasound recording of transmitral and pulmonary venous inflow is used in the assessment of left ventricular diastolic function. However, in patients with mitral stenosis, the conventional transmitral Doppler is altered by mitral stenosis itself and thus precludes the proper assessment of LV diastolic function.3 Pulsed tissue Doppler is relatively a recent technique that is relatively preload independent and thus can play a promising role in the assessment of LV diastolic function in patients with mitral stenosis.

2. Aim of the work

The aim of this work is to assess LV diastolic function using pulsed tissue Doppler interrogation of mitral annulus motion in patients with rheumatic mitral stenosis.

3. Patients and methods

Twelve patients with established diagnosis of rheumatic mitral stenosis in normal sinus rhythm were obtained from outpatient clinic of Cardiology Department in Mansura specialized hospital. Thirteen age and sex matched controls with completely normal echo-Doppler study were taken for comparison. Patients with chronic atrial fibrillation, other valvular heart disease, diabetes, hypertension, renal failure and other disease abnormalities known to alter LV diastolic function were excluded from the study.

All patients were subjected to thorough history taking including dyspnea grading according to NYHA score, clinical examination, 12 lead surface electrocardiogram and most importantly echo-Doppler study.

3.1. Echo-Doppler study

We used a GE VingMed Vivid S5 echocardiographic system (GE Ultrasound; Horten, Norway) with a 2.5-5 MHz linear phased array transducer. Echocardiographic studies were performed in the parasternal long and short axis, apical 2-cham-ber, and 4-chamber views, with patients in the left lateral decubitus position according to AHA recommendations.4

Table 1 Comparative analysis of some m-mode echo parameters in mitral stenosis patients and control.

Parameter Group N Mean SD Mann-Whitney U P value

LATD Control 13 2.9623 0.5828 1.500 0.000

Mitral stenosis 12 4.6033 0.5720

ARD Control 13 2.4808 0.4091 31.000 0.521

Mitral stenosis 12 2.6200 0.2546

LVESD Control 13 2.6923 0.3730 21.500 0.127

Mitral stenosis 12 3.1250 0.5438

LVEDD Control 13 4.3692 0.6356 19.500 0.087

Mitral stenosis 12 4.8300 0.3049

IVSD Control 13 0.9154 0.1908 31.000 0.521

Mitral stenosis 12 0.9817 0.2184

IVSS Control 13 1.1923 0.2397 28.500 0.368

Mitral stenosis 12 1.3233 0.2062

PWd Control 13 0.7923 0.2326 25.500 0.244

Mitral stenosis 12 0.8933 0.2297

PWs Control 13 1.4385 0.3906 26.500 0.282

Mitral stenosis 12 1.4783 0.1217

EF Control 13 0.6838 4.753E- 02 25.500 0.244

Mitral stenosis 12 0.5447 0.2097

FS Control 13 0.3815 3.760E- 02 27.000 0.323

Mitral stenosis 12 0.4567 0.1563

Planimetred mitral valve area Control 13 4.5358 1.6573 0.001 0.000

Mitral stenosis 12 1.3917 0.2529

3.2. m-Mode and 2-dimensional study

The following m-mode parameters were obtained guided by parasternal long axis view; end-diastolic and end-systolic diameters of the LV, interventricular and posterior left ventricular wall thickness in systole and diastole. Left ventricular ejection fraction was obtained by using Simpson's biplane methods in 2-dimensional echocardiography. Mitral valve area

was measured by mitral orifice planimetry in parasternal short axis view, and by the Doppler derived pressure halftime method.

3.3. Conventional Doppler echocardiography

Two-dimensional color Doppler interrogation of apical 4-chamber view is used to guide cursor placement in the most

Table 2 Comparative analysis between some conventional Doppler parameters in mitral stenosis patients and control.

Group N Mean SD Mann-Whitney U P value

Peak transmitral E wave velocity Control 13 1.0835 0.7074 6.000 0.002

Mitral stenosis 12 2.1417 0.5597

Peak transmitral A wave velocity Control 13 0.5950 0.1771 0.000 <0.0001

Mitral stenosis 12 2.0700 0.5332

Transmitral E/A ratio Control 13 1.6161 0.5164 8.500 0.007

Mitral stenosis 12 1.0495 0.1695

Mean transmitral diastolic gradient Control 13 2.2618 0.8281 0.000 <0.0001

Mitral stenosis 12 12.0667 6.5551

Table 3 Comparative analysis between tissue Doppler parameters in mitral stenosis patients and control.

Parameter Group N Mean SD Mann-Whitney U P value

Peak E wave velocity of septal part of mitral annulus Control 13 0.1523 0.02651 0.000 <0.0001

Mitral stenosis 12 0.05500 0.01378

Peak A wave velocity of septal part of mitral annulus Control 13 0.08769 0.02006 26.000 0.282

Mitral stenosis 12 0.07833 0.01169

Ea/Aa ratio of septal portion of mitral annulus Control 13 1.8369 0.5806 0.000 <0.0001

Mitral stenosis 12 0.7005 0.1549

Peak E wave velocity of lateral part of mitral annulus Control 13 0.2046 0.03865 0.000 <0.0001

Mitral stenosis 12 0.07 0.01789

Peak A wave velocity of lateral part of mitral annulus Control 13 0.09385 0.02567 28.500 0.368

Mitral stenosis 12 0.1167 0.04761

Ea/Aa ratio of lateral portion of mitral annulus Control 13 2.3738 0.8407 0.000 <0.0001

Mitral stenosis 12 0.6814 0.2617

Peak E wave velocity of anterior part of mitral annulus Control 13 0.1692 0.02216 0.000 <0.0001

Mitral stenosis 12 0.075 0.02811

Peak A wave velocity of anterior part of mitral annulus Control 13 0.09231 0.02006 27.500 0.323

Mitral stenosis 12 0.08.333 0.01506

Ea/Aa ratio of anterior portion of mitral annulus Control 13 2.0031 0.6181 4.000 0.001

Mitral stenosis 12 0.9319 0.4168

Peak E wave velocity of inferior part of mitral annulus Control 13 0.1892 0.04271 0.000 0.000

Mitral stenosis 12 0.07667 0.01751

Peak A wave velocity of inferior part of mitral annulus Control 13 0.1023 0.01787 26.000 0.282

Mitral stenosis 12 0.09667 0.03327

Ea/Aa ratio of inferior portion of mitral annulus Control 13 1.8802 0.4468 0.000 <0.0001

Mitral stenosis 12 0.8185 0.1202

Averaged mitral annulus peak E velocity Control 13 0.1788 0.02611 0.000 <0.0001

Mitral stenosis 12 0.06917 0.01114

Avearged mitral annulus peak A velocity Control 13 0.09404 0.01716 39.000 1.000

Mitral stenosis 12 0.09375 0.02279

Avearged mitral annulus E/A ratio Control 13 2.0235 0.5223 0.000 <0.0001

Mitral stenosis 12 0.7831 0.1232

turbulent area of transmitral flow in apical 4-chamber view. Continuous Doppler was recorded. The following parameters were taken: mean transmitral pressure gradients, peak early diastolic and atrial systolic transmitral flow velocities and E/ A ratio.

3.4. Tissue Doppler echocardiography

Pulsed-wave TDE was performed by activating the TDE function on the same echocardiography machine. In the apical 4-chamber view, the TDE cursor sample volume was placed at

Figure 1 Pulsed TDI septal mitral annular recording in one control person showing higher Ea compared with Aa

Figure 2 Pulsed TDI lateral mitral annular recording in one control person showing higher Ea compared with A

the septal and lateral sides of the mitral annulus. Apical 2-chamber view was obtained by rotating the transducer 60 degrees counterclockwise from apical 4-chamber view, the TDE cursor was then placed at the anterior and inferior sides of the mitral annulus in the same manner. The following parameters were recorded from the four sites of mitral annulus: peak early diastolic wave of the mitral annulus (Ea), peak atrial dia-stolic wave of the mitral annulus (Aa) and the ratio between both waves. Three consecutive cycles were obtained and averaged.

3.5. Statistical analysis

The SPSS statistical program version 10 (SPSS Inc., Chicago, IL) was used for statistical study. Continuous variables were given as mean ± SD, and categorical variables were given as percentages. A value of P < 0.05 was considered statistically significant.

4. Results

Table 1 showed statistically significant larger left atrial transverse diameter (LATD) in mitral stenosis patients compared with the controls. On the other hand, the planimetered mitral valve area was statistically significantly smaller in patients with mitral stenosis patients compared with the controls. There was no statistically significant difference regarding other m-mode related variables between both groups.

Table 2 showed statistically significant higher transmitral peak diastolic E and A velocities in mitral stenosis patients compared with controls whereas E/A ratio was higher in the controls compared with mitral stenosis patients. In addition, the mean transmitral diastolic gradient was higher in mitral stenosis patients compared with controls.

Table 3 showed statistically significant higher peak mitral annular Ea velocity from septal, anterior, inferior and lateral

portions of the mitral annulus in the controls compared with mitral stenosis patients as well as their averaged values. There is no statistically significant difference regarding peak mitral annular Aa velocity from septal, anterior, inferior lateral portions of the mitral annulus between both groups as well as their averaged values. The ratio of early to late mitral annular velocities from all recorded sites was statistically significantly higher in the controls compared with mitral stenosis (Figs. 1-6).

5. Discussion

In the present study we observed significantly higher peak early E wave transmitral velocity in mitral stenosis patients compared with the control. This is because the narrowed mitral orifice will cause increase in the whole transmitral velocities for any given transmitral flow rate according to the conservation of mass principle. Also the narrower the mitral orifice, the slower the peak early diastolic velocity decay and the higher the subsequent transmitral A wave peak velocity with the consequence of reversed transmitral E/A ratio. Thus, conventional transmitral Doppler cannot be used to assess LV diastolic function in patients with significant mitral stenosis due to the natural tendency in mitral stenosis patients of reduction or even reversal of transmitral early to late diastolic velocities ratio.5 Furthermore, the markedly turbulent diastolic transmitral flow jet inside the LV cavity precludes the utilization of early LV propagation velocity by color m-mode to assess LV diastolic function. This leaves TD of mitral annulus as the remaining method for assessing LV diastolic function. Tissue Doppler imaging of the heart is a Doppler technique that measures the frequency of ultrasound returning from moving myocardium to estimate the velocity of the myocardial wall.6 It was shown that TD-derived Ea correlated with the invasively measured LV time constant of relaxation (Tau), establishing

Figure 3 Pulsed TDI septal mitral annular recording in one mitral stenosis patient showing lower Ea compared with Aa

Figure 4 Pulsed TDI lateral mitral annular recording in one mitral stenosis patient showing lower Ea compared with Aa

Figure 5 Conventional Doppler parameters in mitral stenosis patients and control.

Figure 6 Comparison of some pulsed TDI parameters between mitral stenosis patients and control.

Ea as a relatively load-independent measure of myocardial relaxation in patients with cardiac disease.7 Using spectral TD, impaired myocardial relaxation is generally present when Ea is less than 10 cm/s and severely impaired when Ea is less than 6 cm/s.8 In our study we demonstrated consistently reduced tissue Doppler derived early diastolic Ea velocity from all regions of the mitral annulus in patients with mitral stenosis compared with the control. Since Ea is relatively preload independent parameter, this observation denotes variable degrees of LV diastolic dysfunction in mitral stenosis patients. These findings are consistent with previous reports.5,9 There is controversy regarding whether this deterioration is a result of functional or myocardial factors. Chronic preload reduction with its consequences on LV filling had been implicated as a

functional mechanism. On the other hand, varying degrees of ultrastructural pathologic alterations in LV myocardial cells and in surrounding elements of the sarcoplasm and membranes had been reported in all patients with mitral stenosis regardless of the level of LV systolic function.2 Although these changes do not correlate with the severity of mitral stenosis, more extensive loss of myofibrils has been reported in patients with abnormal LV function. Furthermore, most patients with impaired LV ejection fraction showed improvement after mitral valvuloplasty,3 but other patients did not. This finding indicates that both myocardial and mechanical factors are important in the pathogenesis of LV functional deterioration in patients with mitral stenosis. This has many potential implications. First, it explains the lack of perfect correlation be-

tween mitral valve area and NYHA of dyspnea. Second, the persistence of symptoms after successive valvuloplasty despite adequate increase in the mitral valve area.

References

1. Turi ZG. Cardiology patient page. Mitral valve disease. Circulation 2004;109(6):e38-41.

2. Lee YS, Lee CP. Ultrastructural pathological study of left ventricular myocardium in patients with isolated rheumatic mitral stenosis with normal or abnormal left ventricular function. Jpn Heart J 1990;31(4):435-48.

3. Lee TM, Su SF, Chen MF, Liau CS, Lee YT. Changes of left ventricular function after percutaneous balloon mitral valvulo-plasty in mitral stenosis with impaired left ventricular performance. Int J Cardiol 1996;56(3):211-5.

4. Sahan DJ, De Maria A, Kisslo J, et al. Recommendations regarding quantitation in m-mode echocardiography: results of a survey of echocardiographic measurements. Circulation 1978;58:1072.

5. Özdemir K, Altunkeser BB, Gok H, Icli A, Temizhan A. Analysis of the myocardial velocities in patients with mitral stenosis. J Am Soc Echocardiogr 2002;15(12):1472-8.

6. Isaaz K, Thompson A, Ethevenot G, Cloez JL, Brembilla B, Pernot C. Doppler echocardiographic measurement of low velocity motion of the left ventricular posterior wall. Am J Cardiol 1989;64:66-75.

7. Sohn DW, Chai IH, Lee DJ, et al3. Assessment of mitral annulus velocity by Doppler tissue imaging in the evaluation of left ventricular diastolic function. J Am Coll Cardiol 1997;30:474-80.

8. Alam M, Wardell J, Andersson E, Samad BA, Nordlander R. Characteristics ofmitral and tricuspid annular velocities determined by pulsed wave Doppler tissue imaging in healthy subjects. J Am Soc Echocardiogr 1999;12:618-28.

9. Özdemir K, Altunkeser BB, Gok H, Icli A. Does the myocardial performance index affect pulmonary artery pressure in patients with mitral stenosis? A tissue Doppler imaging study. Echocardiography 2003;20(3):249-56.