Pulsed tissue Doppler imaging detects early myocardial dysfunction in asymptomatic patients with severe mitral regurgitation

Progressive nature of chronic mitral regurgitation and the role of tissue Doppler-derived indexes

The aim of this study was to determine whether severe mitral regurgitation (MR) is progressive and whether tissue-Doppler (TD)-derived indexes can detect early left ventricular (LV) dysfunction in chronic severe MR. Percutaneous rupture of mitral valve chordae was performed in pigs ( n = 8). Before MR (baseline), immediately after MR (post-MR), and at 1 and 3 mo after MR, cardiac function was assessed using conventional and TD-derived indexes. The severity of MR was quantified using regurgitant fraction and effective regurgitant orifice area (EROA). In all animals, MR was severe. On follow-up, the LV dilated progressively over time, but LV ejection fraction did not decrease. With the increase in LV dimensions, the forward stroke volume remained unchanged, but the mitral annular dimensions, EROA, and regurgitant fraction increased (EROA = 41 ± 2 and 51 ± 2 mm2 post-MR and at 3 mo, respectively, P < 0.01). Peak systolic myocardial velocities, strain, and strain rate increased acutely post-MR and remained elevated at 1 mo but declined by 3 mo (anterior strain rate = 2.9 ± 0.1 and 2.4 ± 0.2 s−1 post-MR and at 3 mo, respectively, P < 0.001). Therefore, in a chronic model of MR, serial echocardiography demonstrated that MR begets MR and that those TD-derived indexes that initially increased post-MR decreased to baseline before any changes in LV ejection fraction.

The role of left ventricular long axis contraction in patients with asymptomatic non-ischemic mitral valve regurgitation and normal systolic function

BACKGROUND

Several indices have been proposed in order to better evaluate chronic mitral regurgitation, however, none of them is unique, thus underlying the diagnostic deficiency. We aimed to investigate the role of long axis contraction in both ventricles in patients with non-ischemic asymptomatic mitral regurgitation (MR).

METHODS

Eighty-nine patients (40 men, mean age 59.9+/-13.5 years) with non-ischemic asymptomatic MR along with 50 healthy controls were studied. An echocardiographic, including tissue Doppler imaging study, an exercise radionuclide cineangiography and a cardiac catheterization were also performed.

RESULTS

Fifty of 89 patients (56.2%) had a normal response of left ventricular (LV) ejection fraction on exercise. LV end-diastolic diameter and volume index were significantly higher in patients with an impaired LV response. Moreover, systolic wave maximal velocity and systolic wave slope both at the lateral wall and at the inter-ventricular septum were significantly lower in patients with an impaired LV response. Systolic wave maximal velocity at the lateral wall was the index that best predicted LV response to exercise; while a cutoff value of 9.5 cm/s predicted an impaired LV response with a sensitivity of 96% and a specificity of 100%. MR as defined by the width of vena contracta, was mild/moderate in 78% of patients with a systolic wave maximal velocity at the lateral wall >9.5 cm/s and severe in 69.2% of patients with a velocity <9.5 cm/s.

CONCLUSION

In patients with asymptomatic non-ischemic MR, the evaluation of LV long axis contraction at rest can unmask a subnormal LV functional status.

Detection of myocardial dysfunction in the presence of normal ejection fraction

Detection of subclinical myocardial involvement is of utmost importance in risk stratification and prognosis; the role of ejection fraction in the detection of subclinical disease may be unhelpful. Our aim was to evaluate the methodology and importance of early detection of myocardial involvement in the presence of normal ejection fraction. Most of the pertinent English and non-English articles published from 1980 to 2006 in Medline, Scopus, and EBSCO Host research databases have been reviewed. Serial assessment of systolic function with different techniques should be avoided, since imaging modalities and ejection fraction measurements are not interchangeable. Additional non-invasive tools still are needed for the identification of subclinical left ventricular dysfunction in certain diseases. The recognition of subclinical involvement will prompt initiation of specific therapy to prevent the development of overt left ventricular dysfunction. This also is needed for determining the best timing for intervention in asymptomatic patients with metabolic and valvular disorders.

Assessment of Myocardial Velocities and Global Function of the Left Ventricle in Asymptomatic Patients with Moderate-to-Severe Chronic Aortic Regurgitation: A Tissue Doppler Echocardiographic Study

OBJECTIVE

Asymptomatic patients with chronic aortic regurgitation (AR) have an excellent prognosis in the presence of preserved systolic function. It is a challenge to recognize patients with subclinical myocardial dysfunction in AR. Conventional parameters still have many drawbacks in predicting early left ventricular (LV) dysfunction. Pulsed-wave tissue Doppler imaging (PW-TDI) is a useful noninvasive technique for evaluating global and regional LV systolic function. In this study, we aimed to assess clinical usefulness of TDI in predicting early disturbance of myocardial contractility in asymptomatic patients with significant AR and preserved left ventricular systolic function.

METHODS AND THE RESULTS

Echocardiograms were obtained in 32 AR patients and 33 healthy subjects. In addition to conventional parameters, regional myocardial velocities, isovolumetric contraction time (mICT), isovolumetric relaxation time (mIRT), and ejection time (mET) of left ventricle were obtained by TDI and modified LV myocardial performance index (MPI) was calculated. In AR, peak systolic velocity (Sm) of septal and anterior mitral annulus, and mean Sm was significantly lower, and LVMPI was significantly higher compared to control group.

CONCLUSION

The data obtained by TDI show that LV MPI is lengthened, and systolic myocardial velocities are shortened in patients having chronic AR with normal LV systolic function according to conventional echocardiographic parameters. This suggests that LV long-axis contraction and global LV performance are preciously and noticeably decreased in patients with moderate-to-severe chronic AR despite normal LV ejection fraction.

Changes in systolic left ventricular function in isolated mitral regurgitation. A strain rate imaging study

AIMS

The aim of the present study is to understand the changes in left ventricular (LV) regional systolic deformation based on strain rate (SR) imaging in patients with isolated mitral regurgitation (MR). Progressive LV dilatation and irreversible myocardial damage as a result of chronic isolated MR are important causes of morbidity and mortality in patients following valve surgery. To date, there is no specific diagnostic method to detect subclinical changes in systolic function before irreversible dysfunction occurs.

METHODS AND RESULTS

Seventy-seven individuals were studied: 54 asymptomatic patients (age 56 +/- 12) with isolated non-ischaemic MR divided into three groups: mild, moderate, and severe and 23 healthy subjects. All underwent a standard echo examination and a tissue Doppler study. A mathematical study was carried out to predict how SR should alter with increasing dimensions and due to irreversible myocardial damage. Radial as well as longitudinal peak systolic SR was significantly decreased in patients with severe MR compared to the other groups (LV posterior wall: P = 0.0006, septum: P = 0.0004, LV lateral wall: P = 0.0003). From both modelling and in our patients, deformation correlated inversely with LV end-diastolic diameter and end-systolic diameter (ESD). Deformation measurements (corrected for increased geometry) enabled the identification of patients classically referred to as at risk of irreversible myocardial damage (ESD > or = 4.5 cm).

CONCLUSION

In patients with a wide range of MR, deformation remains unchanged due to a balance of increased dimensions and increased stroke volume. Only when contractility is expected to change, deformation will significantly decrease. SR imaging indices, corrected for geometry, might potentially be useful in detecting subclinical deterioration in LV function in asymptomatic patients with severe MR.

Tissue Doppler imaging a new prognosticator for cardiovascular diseases

Tissue Doppler imaging (TDI) is evolving as a useful echocardiographic tool for quantitative assessment of left ventricular (LV) systolic and diastolic function. Recent studies have explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as heart failure, acute myocardial infarction, and hypertension. In these conditions, myocardial mitral annular or basal segmental (Sm) systolic and early diastolic (Ea or Em) velocities have been shown to predict mortality or cardiovascular events. In particular, those with reduced Sm or Em values of <3 cm/s have a very poor prognosis. In heart failure and after myocardial infarction, noninvasive assessment of LV diastolic pressure by transmitral to mitral annular early diastolic velocity ratio (E/Ea or E/Em) is a strong prognosticator, especially when E/Ea is > or =15. In addition, systolic intraventricular dyssynchrony measured by segmental analysis of myocardial velocities is another independent predictor of adverse clinical outcome in heart failure subjects, even when the QRS duration is normal. In heart failure patients who received cardiac resynchronization therapy, the presence of systolic dyssynchrony at baseline is associated with favorable LV remodeling, which in turn predicts a favorable long-term clinical outcome. Finally, TDI and derived deformation parameters improve prognostic assessment during dobutamine stress echocardiography. A high mean Sm value in the basal segments of patients with suspected coronary artery disease is associated with lower mortality rate or myocardial infarction and is superior to the wall motion score.

Abnormal Tissue Doppler Images are Associated With Elevated Plasma Brain Natriuretic Peptide and Increased Oxidative Stress in Acute Kawasaki Disease

BACKGROUND

The aims of this study were to evaluate myocardial mechanics using pulsed tissue Doppler imaging (TDI), and to determine the relationship between abnormal myocardial performance and plasma brain natriuretic peptide (BNP) levels and oxidative stress in acute Kawasaki disease (KD).

METHODS AND RESULTS

Consecutive TDI parameters, including peak systolic velocity (Sw) and early (Ew) and late diastolic excursion of the mitral annuli were obtained in 42 patients with KD (mean age: 2.4+/-0.4 years) in weeks 1, 2, and 3, and during convalescence. Plasma BNP level and urinary 8-isoprostane were also examined during the acute phase. These data were then compared with TDI profiles from 62 healthy children, plasma BNP levels in 38 controls with other febrile illnesses, and urinary 8-isoprostane levels in 13 healthy children. Ew in week 1 was significantly lower than in controls, subsequently normalizing in the convalescent stage. Plasma BNP level in acute KD patients was significantly higher (65+/-9 pg/ml) than in controls (13+/-2 pg/ml). Urinary 8-isoprostane level in acute KD patients was significantly higher as compared with control (596 +/-37 vs 379+/-26 pg/ml Cr, p<0.05). There was a significant negative correlation between week 1 Sw and plasma BNP level (r=-0.55, p=0.0001). Change in Sw velocity in the BNP >/=51 group was significantly greater than in the BNP <51 group. There was a significant negative correlation between week 1 Sw and urinary 8-isoprostane level (r=-0.48, p=0.001).

CONCLUSIONS

Latent abnormal tissue Doppler profiles, possibly reflecting long-axis systolic and diastolic dysfunction have been noted in KD patients. Abnormal myocardial mechanics may contribute to the increased plasma BNP level and enhanced oxidative stress may contribute to cardiac dysfunction in KD.

Longitudinal left ventricular contractile dysfunction after exercise in aortic stenosis

OBJECTIVE

To determine whether longitudinal left ventricular systolic function measured by Doppler tissue imaging (DTI) after exercise can identify early left ventricular dysfunction in asymptomatic patients with moderate-severe aortic stenosis.

DESIGN

Case-control study.

SETTING

Outpatient cardiology departments.

PATIENTS

20 patients with aortic stenosis, with or without equivocal symptoms, a peak aortic valve velocity > or =3 m/s, and left ventricular ejection fraction >50% and 15 aged-matched normal controls.

INTERVENTIONS

Echocardiogram performed at rest and immediately after treadmill exercise.

MAIN OUTCOME MEASURES

The peak systolic velocity of the lateral mitral annulus (S') by DTI at rest and immediately after exercise, exercise capacity, exercise systolic blood pressure and the plasma level of B-type natriuretic peptide (BNP).

RESULTS

For patients with aortic stenosis, mean (SD) aortic valve area was 0.95 (0.3) cm(2). At rest, S' was similar for patients with aortic stenosis and controls, respectively (8.5 (1.5) vs 9.1 (1.8) cm/s, p = 0.15). However, after exercise, S' (12.2 (3.2) vs 17 (2.8) cm/s, p<0.001) and the increase in S' between rest and exercise (4 (3) vs 7.9 (1.5) cm/s, p<0.001) were lower in patients with aortic stenosis. In patients with aortic stenosis, a smaller increase in S' after exercise was associated with lower exercise capacity (r = 0.5, p = 0.02), a smaller increase in exercise systolic blood pressure (r = 0.6, p = 0.005) and higher plasma level of BNP (r = 0.66, p = 0.002).

CONCLUSION

In asymptomatic patients with moderate-severe aortic stenosis a lower than normal increase in peak systolic mitral annular velocity after treadmill exercise is a marker of early left ventricular systolic dysfunction.

Systolic Dysfunction in Heart Failure with a Normal Ejection Fraction: Echo-Doppler Measurements

Heart failure with a normal ejection fraction, also called heart failure with preserved ejection fraction or diastolic heart failure, is thought to be characterized by normal systolic function and disturbed diastolic function only. However, studies using newer Doppler-echocardiographic techniques have shown that ventricular function is not normal particularly in the long axis. Ejection is relatively preserved because of increased radial function. Similar findings are seen with normal ageing and the typical precursors of heart failure with a normal ejection fraction such as hypertension, diabetes, and ischemia. There appears to be a spectrum of abnormalities of systolic function from the truly normal to systolic heart failure with heart failure with a normal ejection fraction occupying an intermediate position. The use of ejection fraction, which has a normal distribution, to dichotomize patients with heart failure is not supported on theoretical or experimental grounds, and any cutoff is arbitrary. Patients with heart failure have a mixture of systolic and diastolic abnormalities and variable degrees of remodeling. It is more important to correctly identify these in the individual patient.

Left ventricular function after exercise training in young men

The effects of endurance training have been extensively studied in athletes, but longitudinal studies of exercise-induced cardiac changes in normal patients are limited. To assess the effects of 6 months of moderate-intensity aerobic training (1 hour/day, 3 times/week) on normal hearts, 23 sedentary men aged 31.1 +/- 3.5 years were studied by standard and tissue Doppler echocardiography. Left ventricular (LV) systolic function was assessed by the ejection fraction and Doppler-measured stroke volume, and diastolic function was assessed by transmitral and pulmonary venous flow. Tissue Doppler systolic (Sm), early (Em), and late (Am) myocardial velocities were obtained at the septal and lateral mitral annulus. After training, there was a 14.5% increase in peak oxygen consumption (p = 0.000002) and a decrease in heart rate (60 +/- 7 to 56 +/- 8 beats/min, p = 0.01). Septal and posterior wall thickness increased (8.7 +/- 1.0 to 9.4 +/- 1.3 mm, p = 0.002, and 8.2 +/- 0.7 to 8.8 +/- 1.1 mm, p = 0.0009, respectively), with a 15% increase in LV mass index (p = 0.0002). LV diameters, stroke volumes, and ejection fractions were unchanged. Mitral inflow showed a decrease in late-wave velocity (p = 0.00004), thus increasing the early (E)/A ratio. Septal and lateral Sm (p = 0.02) and Em velocities (p <0.05) increased after training. In conclusion, the physiologic increase in LV mass in response to regular exercise in healthy young men occurs in parallel with a decrease in atrial contribution to flow. LV function estimated by tissue Doppler is improved despite the lack of changes in standard echocardiographic indexes.

Doppler tissue imaging: a reliable method for estimation of left ventricular filling pressure in patients with mitral regurgitation

BACKGROUND

Doppler of mitral and pulmonary vein flows are used to estimate left ventricular (LV) filling pressure. Mitral regurgitation (MR) makes unreliable these parameters by inducing changes of both mitral inflow and pulmonary vein flow.

OBJECTIVES

To evaluate whether Doppler tissue imaging (DTI) diastolic indices obtained at the level of LV lateral mitral annulus can provide accurate estimation of LV filling pressure in patients with MR.

METHODS

Forty-three patients (age 55 +/- 11 years) with severe MR and mean LV ejection fraction (EF) 58 +/- 13 were enrolled, 10 (23%) with LV EF < 50% and 33 (77%) with LV EF > 50%. Doppler signals from the mitral inflow, pulmonary venous flow, and DTI indices of the lateral mitral annulus were obtained. LV end-diastolic pressure (LVEDP) was measured invasively with fluid-filled catheter.

RESULTS

In the overall population, the majority of standard Doppler and DTI indices correlated with LVEDP, but the multivariate analysis showed that the ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/Em ratio) (beta = .87, P = .0001) was independent predictor of LVEDP (R2 = 0.74, SE = 4, P = .0001). An E/Em ratio > 10 predicted an LVEDP > 15 mm Hg (sensitivity 90%, specificity 83%). In both groups with LV EF > 50% (beta = .77, P = .005; cumulative R2 = 0.73, SE = 2.5, P = .0001) and < 50% (beta = .89, P = .002; cumulative R2 = 0.77, SE = 2.1, P = .002), multivariate analysis underscored again only E/Em ratio as independent predictor of LVEDP.

CONCLUSIONS

The combination of DTI indices of the mitral annulus and mitral inflow velocities provides reliable parameters to predict LV filling pressure in patients with MR both in patients with LV EF > 50% and < 50%.

Mitral valve prolapse

Mitral valve prolapse is a common valvular abnormality that is the most common cause of severe non-ischaemic mitral regurgitation in the USA. The overall prognosis of patients with mitral valve prolapse is excellent, but a small subset will develop serious complications, including infective endocarditis, sudden cardiac death, and severe mitral regurgitation. We present a comprehensive review of mitral valve prolapse, examining normal mitral anatomy, the clinical and echocardiographic features of mitral valve prolapse, and the pathophysiology and genetics of the disorder. We discuss the contemporary management of both asymptomatic and symptomatic prolapse, with particular attention to the timing and technique of surgical repair. We conclude that echocardiography is the method of choice for diagnosing mitral valve prolapse, that clinical and echocardiographic features can predict which patients with prolapse are at highest risk for complications, and that mitral valve repair is the treatment of choice for symptomatic prolapse.

Assessment of Left Ventricular Function Using Pulsed Tissue Doppler Imaging in Healthy Dogs and Dogs with Spontaneous Mitral Regurgitation

Pulsed tissue Doppler imaging (pulsed TDI) has been demonstrated to be useful for the estimation of left ventricular (LV) systolic and diastolic functions in various human cardiac diseases. The objectives of this study were to investigate the relationship between pulsed TDI and LV function by using cardiac catheterization in healthy dogs and to evaluate the clinical usefulness of pulsed TDI in dogs with spontaneous mitral regurgitation (MR). The peak early diastolic velocity (E'), peak atrial systolic velocity (A'), and peak systolic velocity (S') were detectable in the velocity profiles of the mitral annulus in all the dogs. In the healthy dogs, S' and E' were correlated with LV peak +dP/dt and -dP/dt, respectively. E' was lower in dogs with MR than in dogs without cardiac diseases. E/E' in the MR dogs with decompensated heart failure was significantly increased in comparison with those with compensated heart failure. The sensitivity and specificity of the E/E' cutoff value of 13.0 for identifying decompensated heart failure were 80% and 83%, respectively. In addition, E/E' was significantly correlated with the ratio of left atrial to aortic diameter. These findings suggest that canine pulsed TDI can be applied clinically for estimation of cardiac function and detection of cardiac decompensation and left atrial volume overload in dogs with MR.

Tissue Doppler imaging for predicting outcome in patients with cardiovascular disease

PURPOSE OF REVIEW

Tissue Doppler imaging is being increasingly used for assessing global ventricular function in systole and diastole, and for quantifying regional wall motion abnormalities both in systolic heart failure with mechanical dyssynchrony and ischemic heart disease. Its use as a predictive tool is recent and the authors review publications relating to this aspect.

RECENT FINDINGS

Peak early diastolic mitral annular velocity is a powerful predictor of outcome in a variety of cardiovascular conditions and adds incremental value to clinical parameters and standard mitral Doppler inflow velocities. Tissue Doppler imaging can also predict the development of hypertrophic cardiomyopathy in asymptomatic individuals carrying the genetic mutation even before the onset of overt left ventricular hypertrophy. In addition, the standard deviation of the time to peak systolic velocity is a good marker of mechanical asynchrony and can predict reverse remodeling. It may also be useful in identifying individuals with ischemic heart disease and regional wall motion abnormalities who have an adverse outcome.

SUMMARY

Tissue Doppler imaging is a powerful new echocardiographic tool that is now becoming the standard for assessing ventricular function in a variety of situations and diseases.