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

Prognostic implications of impaired longitudinal left ventricular systolic function assessed by tissue Doppler imaging prior to transcatheter aortic valve implantation for severe aortic stenosis

Change in longitudinal left ventricular (LV) systolic function serves as an early marker of the deleterious effect of aortic stenosis (AS) and other cardiac comorbidities on cardiac function. We explored the prognostic value of tissue Doppler imaging (TDI)-derived longitudinal LV systolic function, defined by the peak systolic average of lateral and septal mitral annular velocities (average S') among symptomatic patients with severe AS undergoing transcatheter aortic valve implantation (TAVI). 297 consecutive patients with severe AS undergoing TAVI at three european centers with available average S' at preprocedural echocardiography were retrospectively included. The primary endpoint was the Kaplan Meier estimate of all-cause mortality. After a median 18 months (IQR 12-18) follow-up, 36 (12.1%) patients had died. Average S' was associated with all-cause mortality (per 1 cm/sec decrease: HR 1.29, 95%CI 1.03-1.60, p = 0.025), the cut-off of 6.5 cm/sec being the most accurate. Patients with average S' < 6.5 cm/sec (55.2%) presented characteristics of more advanced LV remodeling and functional impairment along with higher burden of cardiac comorbidities, and experienced higher all-cause mortality (17.6% vs. 7.5%, p = 0.007), also when adjusted for in-study outcome predictors (adj-HR: 2.69, 95%CI 1.22-5.93, p = 0.014). Results were consistent among patients with preserved ejection fraction, normal-flow AS, high-gradient AS and in those without LV hypertrophy. Longitudinal LV systolic function assessed by average S' is independently associated with long-term all-cause mortality among TAVI patients. An average S' below 6.5 cm/sec best defines clinically meaningful reduced longitudinal systolic function and may aid clinical risk stratification in these patients.

The evolving role of cardiac magnetic resonance in primary mitral regurgitation: ready for prime time?

A fifth of patients with primary degenerative mitral regurgitation continue to present with de novo ventricular dysfunction following surgery and higher rates of heart failure, morbidity, and mortality. This raises questions as to why the left ventricle (LV) might fail to recover and has led to support for better LV characterization; cardiac magnetic resonance (CMR) may play a role in this regard, pending further research and outcome data. CMR has widely acknowledged advantages, particularly in repeatability of measurements of volume and ejection fraction, yet recent guidelines relegate its use to cases where there is discordant information or poor-quality imaging from echocardiography because of the lack of data regarding the CMR-based ejection fraction threshold for surgery and CMR-based outcome data. This article reviews the current evidence regarding the role of CMR in an integrated surveillance and surgical timing programme.

Pharmacodynamic Analysis of the Influence of Propofol on Left Ventricular Long-Axis Systolic Performance in Cardiac Surgical Patients

BACKGROUND

Propofol induced a decline in the left ventricular (LV) systolic performance in non-cardiac surgery. We tested the hypothesis that propofol decreased the LV contractile function by dose dependent manner in cardiac surgery patients.

METHODS

Anesthesia was maintained with target-controlled infusions of propofol and remifentanil in cardiac surgery patients. With a fixed effect-site concentration (Ce) of remifentanil (20 ng/mL) after sternotomy, the Ce of propofol was adjusted to maintain a Bispectral index of 40-60 (Ce1). Mitral annular Doppler tissue image tracings and other echocardiographic variables, including end-diastolic and end-systolic volumes, stroke volume, and mitral inflow pulse wave Doppler profile at Ce1, were recorded using transesophageal echocardiography. Echocardiographic recordings were repeated after the Ce-values of propofol were doubled and tripled at 10-minute intervals (defined as Ce2 and Ce3, respectively). Serial changes in echocardiographic variables for each Ce of propofol were assessed using generalized linear mixed effect modeling. The pharmacodynamic relationship between the Ce of propofol and peak systolic mitral annular velocity (Sm) was analyzed by logistic regression using non-linear mixed effect modeling (NONMEM).

RESULTS

Means of Ce1, Ce2, and Ce3 were 0.8, 1.6, and 2.4 μg/mL, respectively, and their means of Sm (95% confidence interval) were 9.7 (9.3-10.2), 8.7 (8.2-9.1), and 7.5 cm/sec (7.0-8.0), respectively (P < 0.01). Ce values of propofol and Sm showed a significant inter-correlation and predictability (intercept, 10.8; slope-1.0 in generalized mixed linear modeling; P < 0.01). Ce values producing 10% and 20% decline of Sm with 50%-probability were 1.4 and 2.1 μ/mL, respectively.

CONCLUSION

Propofol reduces LV systolic long-axis performance in a dose-dependent manner.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01826149.

A prospective study examining the role of myocardial Fibrosis in outcome following mitral valve repair IN DEgenerative mitral Regurgitation: rationale and design of the mitral FINDER study

Background

The optimal management of chronic severe primary degenerative mitral regurgitation (MR) is to repair the valve but identification of the optimal timing of surgery remains challenging. Current guidelines suggest ‘watchful waiting’ until the onset of symptoms or left ventricular (LV) dysfunction but these have been challenged as promoting ‘rescue surgery’. Better predictors are required to inform decision-making in relation to the necessity and timing of surgery. Chronic volume overload is a stimulus for adverse adaptive LV remodelling. Subclinical reduction in LV strain before mitral repair predicts a fall in LV ejection fraction following surgery and is thought to reflect the development of myocardial fibrosis in response to chronic volume overload. Myocardial fibrosis can be detected non-invasively using cardiac magnetic resonance (CMR) imaging techniques as an expansion of the extracellular volume (ECV).

Methods/design

This study investigates whether: 1) patients with above median ECV will have smaller reduction in end-systolic volume index (as a measure of the degree of reverse LV remodelling) on CMR following mitral valve repair, compared to those with below median ECV; and 2) higher ECV on CMR, validated through histology, adversely impacts upon post-operative complications and symptomatic improvement following surgery.

This is a multi-centre, prospective, cross-sectional comparison of patients prior to and 9 months following surgery for chronic severe primary degenerative MR. To establish the natural history of ECV in MR, an additional cohort of patients with asymptomatic MR who do not wish to consider early repair will be followed. Investigations include CMR, cardiopulmonary exercise test, stress echocardiography, signal-averaged electrocardiogram, 24-h electrocardiogram monitoring, laboratory tests and patient-reported outcome measures. Patients undergoing surgery will have cardiac biopsies performed at the time of mitral valve repair for histological quantification of fibrosis.

Discussion

This study will advance our understanding of ventricular remodelling in MR, its impact on patient symptoms and ventricular response following surgery. Establishing the link between myocardial fibrosis (measured on CMR and validated through histology), with early ventricular dysfunction, will offer physicians a novel non-invasive biomarker that can further inform the timing of surgery.

Trial registration

This trial was registered at ClinicalTrials.gov (NCT02355418) on 30th November 2015.

The modern role of transoesophageal echocardiography in the assessment of valvular pathologies

Despite significant advancements in the field of cardiovascular imaging, transoesophageal echocardiography remains the key imaging modality in the management of valvular pathologies. This paper provides echocardiographers with an overview of the modern role of TOE in the diagnosis and management of valvular disease. We describe how the introduction of 3D techniques has changed the detection and grading of valvular pathologies and concentrate on its role as a monitoring tool in interventional cardiology. In addition, we focus on the echocardiographic and Doppler techniques used in the assessment of prosthetic valves and provide guidance for the evaluation of prosthetic valves. Finally, we summarise quantitative methods used for the assessment of valvular stenosis and regurgitation and highlight the key areas where echocardiography remains superior over other novel imaging modalities.

Timing surgery in mitral regurgitation: defining risk and optimising intervention using stress echocardiography

Mitral regurgitation (MR) is the second most common form of valvular disease requiring surgery. Correct identification of surgical candidates and optimising the timing of surgery are key in management. For primary MR, this relies upon a balance between the peri-operative risks and rates of successful repair in patients undergoing early surgery when asymptomatic with the potential risk of irreversible left ventricular dysfunction if intervention is performed too late. For secondary MR, recognition that this is a highly dynamic condition where MR severity may change is key, although data on outcomes in determining whether concomitant valve intervention is performed with revascularisation has raised questions regarding timing of surgery. There has been substantial interest in the use of stress echocardiography to risk stratify patients in mitral regurgitation. This article reviews the role of stress echocardiography in both primary and secondary mitral regurgitation and discusses how this can help clinicians tackle the challenges of this prevalent condition.

Prognostic Importance of Exercise Brain Natriuretic Peptide in Asymptomatic Chronic Organic Severe Mitral Regurgitation: An Observational Study

BACKGROUND

The optimal timing of surgery in patients with chronic organic severe mitral regurgitation (MR) continues to be debated, especially for those who are asymptomatic. The aim of the study was to determine independent and additive prognostic value of exercise brain natriuretic peptide (eBNP) in patients with severe asymptomatic MR and normal left ventricular ejection fraction (LVEF).

METHODS

Two hundred twenty-three consecutive patients with severe MR defined by effective regurgitant orifice (ERO) area ≥ 40 mm² and/or residual volume ≥ 60 mL, LVEF > 60%, and normal LV end-systolic diameter < 40 mm underwent symptom limited exercise treadmill test (TMT). Echocardiography was done immediately after exercise. Data were obtained within 3 minutes of peak exercise. BNP levels were assessed before echo (after 30 minutes of supine rest) and at exercise (i.e., within the 3 minutes of the end of effort). Patients were followed up every 3 months up to 15 months for major adverse cardiac events (MACEs) (cardiovascular death, need for mitral valve surgery and hospitalization for acute pulmonary edema or heart failure).

RESULTS

Mean age was 31.2 ± 9 years (range: 18 - 40) with majority being male (n = 153; 68%). Etiologies were rheumatic (n = 201; 90%), mitral valve prolapse (n = 17; 7.6%) and hypertrophic cardiomyopathy (n = 5; 2.4%). BNP level significantly increased from rest (65.24 ± 43.92 pg/mL; median: 43.5 pg/mL) to exercise (100.24 ± 98.24 pg/mL; median: 66.5 pg/mL; P < 0.001). Patients were divided into three tertiles according to eBNP levels (T₁ = 15 - 44; T₂ = 45 - 104; T₃ = 105 - 400). There was trend for significantly lower exercise time in T₃. During TMT, 66 (29.5%) stopped exercise due to dyspnea. They had similar resting BNP level compared with others but had significantly higher eBNP level (136 ± 109.7 pg/mL vs. 84.88 ± 90.2 pg/mL; P < 0.001). During follow-up (15 months), MACE occurred in 83 patients (37.2%): mitral valve replacement (MVR) in 59 patients (symptomatic: 43; LV dilatation or dysfunction: 9; both symptoms and dilatation/dysfunction: 7), 17 hospitalizations for congestive heart failure, five patients developing acute pulmonary edema and atrial fibrillation in remaining two patients. This was 7.6%, 35% and 69% in T₁, T₂ and T₃, respectively and had significantly higher eBNP level than without any event (165 ± 119 pg/mL vs. 57 ± 48 pg/mL; P < 0.001). Using receiver operating characteristic curve analysis, the best cut-off value of eBNP level to predict cardiac events was 90 pg/mL (sensitivity: 75%; specificity: 88.6%; positive predictive value: 79%; negative predictive value: 83.9%).

CONCLUSION

In asymptomatic patients, eBNP level provides incremental prognostic value beyond echocardiographic data and those with elevated eBNP should be considered at high risk for reduced event-free survival and might be considered for early MVR.

Mechanical dyssynchrony and deformation imaging in patients with functional mitral regurgitation

Chronic functional mitral regurgitation (FMR) is a frequent finding of ischemic heart disease and dilated cardiomyopathy (DCM), associated with unfavourable prognosis. Several pathophysiologic mechanisms are involved in FMR, such as annular dilatation and dysfunction, left ventricle (LV) remodeling, dysfunction and dyssynchrony, papillary muscles displacement and dyssynchrony. The best therapeutic choice for FMR is still debated. When optimal medical treatment has already been set, a further option for cardiac resynchronization therapy (CRT) and/or surgical correction should be considered. CRT is able to contrast most of the pathophysiologic determinants of FMR by minimizing LV dyssynchrony through different mechanisms: Increasing closing forces, reducing tethering forces, reshaping annular geometry and function, correcting diastolic MR. Deformation imaging in terms of two-dimensional speckle tracking has been validated for LV dyssynchrony assessment. Radial speckle tracking and three-dimensional strain analysis appear to be the best methods to quantify intraventricular delay and to predict CRT-responders. Speckle-tracking echocardiography in patients with mitral valve regurgitation has been usually proposed for the assessment of LV and left atrial function. However it has also revealed a fundamental role of intraventricular dyssynchrony in determining FMR especially in DCM, rather than in ischemic cardiomyopathy in which MR severity seems to be more related to mitral valve deformation indexes. Furthermore speckle tracking allows the assessment of papillary muscle dyssynchrony. Therefore this technique can help to identify optimal candidates to CRT that will probably demonstrate a reduction in FMR degree and thus will experience a better outcome.

Cancer and cardiovascular disease: the use of novel echocardiography measures to predict subsequent cardiotoxicity in breast cancer treated with anthracyclines and trastuzumab

As the population of breast cancer survivors grows, it has become evident that chemotherapy has significant cardiotoxic side effects. Echocardiography is a noninvasive, cost-effective, and widely available imaging tool that is well positioned to serve as a primary modality for monitoring chemotherapy-induced cardiotoxicity. Although left ventricular ejection fraction is a standard measurement by which to monitor chemotherapy-induced cardiotoxicity, its predictive value in identifying subsequent cardiotoxicity is limited. More sophisticated echocardiography modalities may offer improved sensitivity and specificity for detecting chemotherapy-induced cardiotoxicity. These include tissue Doppler imaging measures, newer techniques based upon two- and three-dimensional strain and torsion analysis, and three-dimensional measures of cardiac size. While these modalities are not all currently part of clinical practice, a body of data supporting their use is steadily building. More research remains to be performed, and noninvasively detecting cancer therapy-induced cardiac dysfunction at the earliest stages is of increasing interest.

Quantification of Left Ventricular Interstitial Fibrosis in Asymptomatic Chronic Primary Degenerative Mitral Regurgitation

Background—

The optimum timing of surgery in asymptomatic patients with chronic severe primary degenerative mitral regurgitation (MR) remains controversial, and further markers are needed to improve decision-making. There are limited data that wall stress is increased in MR and may result in ventricular fibrosis. We investigated the hypothesis that chronic volume overload in MR is a stimulus for myocardial fibrosis using T1-mapping cardiac MRI.

Methods and Results—

A cross-sectional study of 35 patients (age 60±14 years) with asymptomatic moderate and severe primary degenerative MR (mean effective regurgitant orifice area, 0.45±0.25 cm) 2 with no class I indication for surgery were compared with age and sex controls. Subjects were studied with cardiopulmonary exercise testing, echocardiography, and cardiac MRI.

Longitudinal and circumferential myocardial deformation was reduced with MR when left ventricular ejection fraction (67%±10%) and N-terminal pro B Natriuretic peptide (126 [76–428] ng/L) were within the normal range. Myocardial extracellular volume was increased (0.32±0.07 versus 0.25±0.02, P <0.01) and was associated with increased left ventricular end-systolic volume index ( r =0.62, P <0.01), left atrial volume index ( r =0.41, P <0.05) but lower left ventricular ejection fraction ( r =−0.60, P <0.01), longitudinal function (mitral annular plane systolic excursion, r =−0.46, P <0.01), and peak V O 2 max ( r =−0.51, P <0.05). In a multivariable regression model, left ventricular end-systolic volume index and left atrial volume index were independent predictors of extracellular volume ( r 2 =0.42, P <0.01).

Conclusions—

Patients with asymptomatic MR demonstrate a spectrum of myocardial fibrosis associated with reduced myocardial deformation and reduced exercise capacity. Future work is warranted to investigate whether left ventricle fibrosis affects clinical outcomes.

Tissue Doppler imaging in rheumatic carditis

OBJECTIVE

Our study was undertaken to assess cardiac functions by tissue Doppler echocardiography in patient with primary episode of rheumatic carditis.

METHODS

We divided 82 patients with rheumatic carditis were divided in two groups; 50 patients with mild and 32 patients with mitral regurgitation of grade two or more. A control group consisted of 30 healthy children free of any disease. All children underwent conventional and tissue Doppler echocardiography initially and at the time of the follow-up examination.

RESULTS

Myocardial systolic wave velocity of the mitral annulus was significantly higher in patients with mitral regurgitation of grade two or more when compared to the control group, but was not different between patients with mild mitral regurgitation and healthy subjects at the time of the initial attack. Myocardial precontraction time, myocardial contraction time, and the ratio of myocardial precontraction and contraction times were significantly prolonged, and the systolic myocardial velocity of the mitral annulus was significantly decreased in patients with mitral regurgitation of grade two or more at the time of the follow-up examination. The myocardial systolic wave velocity was significantly lower, and myocardial precontraction time, myocardial contraction time, and the ratio of the precontraction and contraction times, were significantly longer or greater between patients with grade two or more mitral regurgitation and the control group at follow-up examination.

CONCLUSION

We detected subclinical systolic dysfunction of the left ventricle in children with a primary episode of rheumatic carditis due to ongoing ventricular volume overload. Tissue Doppler imaging provides a quantifiable indicator useful for cardiac monitoring of disease during the period of follow up.

Structural and functional left ventricular impairment in subjects with chronic spinal cord injury and no overt cardiovascular disease

CONTEXT

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in subjects with long-term spinal cord injury (SCI). More specific recommendations for CVD prevention in this population are needed.

METHODS

One hundred thirty male subjects (47 subjects with SCI and 83 able-bodied persons (ABPs), mean age 43.89 ± 1.9 and 45.44 ± 12.2 years; P = 0.48) underwent transthoracic echocardiography (TTE). The effects of age, weight, mean arterial pressure (MAP) and level of physical training on cardiac adaptations were evaluated through multiple regression analysis.

RESULTS

In subjects with SCI, TTE revealed increased wall thickness (P < 0.05), lower E wave, E/A ratio and early diastolic myocardial relaxation velocity on Tissue Doppler Imaging (TDI) (P < 0.05) and higher systolic myocardial contraction velocity on TDI (0.10 ± 0.02 vs. 0.09 ± 0.02 m/seconds, P = 0.002) and peak systolic pressure to end-systolic volume ratio (3.62 ± 1.39 vs. 2.82 ± 0.90, P < 0.001) compared with ABPs. Aortic diameters were larger in subjects with SCI than ABPs. Differences remained statistically significant even after adjustment for age, weight, MAP, and level of physical training. Weight and age were found to be independent variables that substantially affected left ventricular structure and function in subjects with SCI.

CONCLUSIONS

Subjects with post-traumatic chronic SCI and no overt cardiovascular risk factors, exhibit initial left ventricular remodeling (as assessed by TTE) compared with ABPs. Lifestyle modifications, including regular physical exercise and weight control, should be implemented in all subjects with SCI, even at a very early stage, in order to reduce cardiovascular risk and prevent the development of CVD.

Surgical timing of degenerative mitral regurgitation: what to consider

Severe primary mitral regurgitation (MR) is a progressive condition which engenders significant mortality and morbidity if left untreated. The optimal timing of surgery in patients with MR of degenerative origin continues to be debated, especially for those who are asymptomatic. Apart from symptoms, current authoritative guidelines recommend intervention when there is incipient left ventricular dysfunction, pulmonary hypertension or new onset atrial fibrillation. This review focuses on the asymptomatic subject with severe MR, and examines contemporary clinical decision-making and management strategies, including the 2012 European guidelines on valvular heart disease. We discuss the rationale for risk stratifying the asymptomatic individual, and highlight current and novel diagnostic tools that may have a useful role, with an emphasis on echocardiographic imaging.

Tissue Doppler imaging predicts adverse outcome in children with idiopathic pulmonary arterial hypertension

OBJECTIVE

To evaluate the clinical utility of tissue Doppler imaging (TDI) in assessment of disease severity and prognostic value in children with idiopathic pulmonary arterial hypertension (PAH).

STUDY DESIGN

A prospective study was performed to evaluate TDI velocities (systolic myocardial velocity, early diastolic myocardial relaxation velocity [Em], late diastolic myocardial velocity associated with atrial contraction), brain natriuretic peptide, New York Heart Association (NYHA) functional class, and hemodynamics in 51 children (mean age; 11.6 years) with idiopathic PAH. Fifty-one healthy children with comparable demographics served as controls.

RESULTS

Em, Em/late diastolic myocardial velocity associated with atrial contraction ratio, and systolic myocardial velocity at mitral annulus, septum, and tricuspid annulus in PAH were significantly reduced compared with controls. Tricuspid Em had significant inverse correlations with plasma brain natriuretic peptide levels (r = -0.60, P < .001), right ventricular end-diastolic pressure (r = -0.79, P < .001), and mean pulmonary arterial pressure (r = -0.67, P < .001). Statistically significant differences were observed in tricuspid Em between NYHA functional class II vs combined III and IV (mean and SD; 11.9 ± 4.2 cm/s vs 8.2 ± 3.6 cm/s, respectively, P = .002). Cumulative event-free survival rate was significantly lower when tricuspid Em was ≤8 cm/s (log-rank test, P < .001)

CONCLUSIONS

Tricuspid Em velocity correlated with NYHA functional class as disease severity and may serve as a useful prognostic marker in children with idiopathic PAH. The present study is the initial report to evaluate TDI velocities against midterm outcome variables in a relatively large pediatric PAH population.

Echocardiography: frontier imaging in cardiology

This article reviews the recent developments in echocardiography that have maintained this technology at the forefront of day-to-day imaging in clinical cardiology. The primary reason for most requests for imaging in cardiovascular medicine is to assess left ventricular structure and function. As our understanding of left ventricular mechanics has become more intricate, tissue Doppler and speckle tracking modalities have been developed that deliver greater insights into diagnosis of cardiomyopathy and earlier warning of ventricular dysfunction. Increased accuracy has been achieved with the dissemination of real-time three-dimensional echocardiography, which has also acquired a central role in the pre-operative assessment of patients prior to reparative valvular surgery. The use of contrast has broadened the indications for transthoracic echocardiography and has increased the accuracy of stress echocardiography, while reducing the number of patients who cannot be scanned because of a limited acoustic window. Finally, echocardiography will be seen in the future not only as a diagnostic tool in those affected by cardiovascular disease but also as a method for prediction of risk and perhaps activation of targeted treatment.

Early prediction of left ventricular systolic dysfunction in patients of asymptomatic chronic severe rheumatic mitral regurgitation using tissue Doppler and strain rate imaging

AIMS

Identification of subclinical left ventricular (LV) dysfunction in patients with rheumatic mitral regurgitation (MR) facilitates optimal surgical results and better postoperative LV function. This study is designed to assess the role of tissue Doppler and strain rate (SR) imaging in early detection of LV systolic dysfunction in patients with asymptomatic chronic severe MR.

METHODS AND RESULTS

Patients were studied under four groups. Group I: Normal subject (n = 25). Group II: Patients with chronic severe MR with ejection fraction (EF) > 60% and end-systolic dimension (ESD) ≤ 40 mm (n=23). Group III: Patients with chronic severe MR with EF ≥ 60% and ESD 41-50 mm (n = 27). Group IV: Patients with chronic severe MR with EF < 60% with any ESDs (n = 25). With decrease in EF and increase in ESD there was decrease in systolic velocity and increased in precontraction time and contraction time was noted. The tissue Doppler systolic indices between groups were statistically significant P < 0.05 and showed significant correlation value r = 0.45 between groups. Strain (S) and SR significantly decreased with decrease in EF and increase in ESD P < 0.05, r = 0.45 between different groups.

CONCLUSION

Our study showed significant correlation between tissue Doppler systolic indices and SR imaging with EF and ESD.

The time-course changes of NT-proBNP and tissue Doppler indices in patients undergoing mitral valve replacement

Background

In severe mitral regurgitation, a subset of patients who are asymptomatic may develop left ventricular decompensation before changes in echocardiographic parameters become evident. Since N-terminal brain natriuretic peptide (NT-proBNP) is used to detect early heart failure, we hypothesised that NT-proBNP would be activated in patients with mitral regurgitation.

Methods

Patients submitted to surgery were prospectively evaluated over eight months in the Department of Cardiology at Inkosi Albert Luthuli Central Hospital. Control patients with severe mitral regurgitation were obtained from the outpatient clinic. In order to define their value in identifying left ventricular decompensation, NT-proBNP levels and tissue Doppler imaging (TDI) indices were simultaneously measured and compared with conventional echocardiographic indices at baseline and this was repeated at one week and at six weeks after valve replacement.

Results

Mean NT-proBNP levels were markedly elevated pre-operatively in all surgical cases compared to controls (p = 0.0001). The diastolic E-mitral/E-annulus ratio, measured using TDI, was higher in the study group, indicating higher left ventricular filling pressure present in the study group. NT-proBNP levels increased further at one week after surgery and subsided at the six-week follow-up visit to levels similar to the control group. The TDI diastolic ratio also decreased at one week, and increased slightly again at the six-week follow up. These changes were accompanied by significant reduction in left atrium and left ventricular chamber dimensions with an increase in the ejection fraction from one to six weeks.

Conclusion

Marked differences in mean NT-proBNP levels and TDI ratios between the study and control groups suggest that using TDI and NT-proBNP assays may detect covert left ventricular decompensation.

Association of heart rhythm with exercise capacity after operation for chronic mitral regurgitation

BACKGROUND

Although atrial fibrillation (AF) and decreased exercise capacity are common in chronic mitral regurgitation patients, the relationship between rhythm status and exercise capacity after corrective surgery is largely unknown.

METHODS

Seventy-one patients undergoing repair or replacement of mitral valve for chronic severe mitral regurgitation were examined with preoperative and 6 months' postoperative cardiopulmonary exercise test and two-dimensional echocardiography. Patients were divided into three groups according to preoperative versus postoperative rhythm (sinus/sinus, SS [n=42]; AF/sinus, AS [n=17]; AF/AF, AA group [n=12]).

RESULTS

Preoperative maximal oxygen consumption was lower and ventilatory efficiency was higher in the AS and AA groups compared with the SS group. However, maximal oxygen consumption improved only in the AS group at 6 months' postoperative cardiopulmonary exercise test (24.0±6.9 versus 24.6±6.1 mL·kg(-1)·min(-1) in the SS group, 19.3±5.9 versus 23.2±6.4 mL·kg(-1)·min(-1) in the AS group, 19.8±5.4 versus 18.8±5.1 mL·kg(-1)·min(-1) in the AA group; p=0.016 for maximal oxygen consumption by analysis of covariance) as well as ventilatory efficiency. Echocardiography verified more significant reduction of left atrial volume in the SS and AS groups than in the AA group (172.2±68.0 versus 96.7±31.0 mL in the SS group, 247.5±77.8 versus 129.2±25.7 mL in the AS group, 316.7±210.0 versus 192.0±95.0 mL in the AA group; p=0.001 for left atrial volume by analysis of covariance) as well as pulmonary artery systolic pressure. When analyzed for significant predictors of postoperative maximal oxygen consumption, being in the AS group but not the SS group was a significant positive predictor when compared with the AA group (β=5.475; p=0.006).

CONCLUSIONS

Successful sinus conversion of AF, preferably by maze operation, in patients undergoing surgical correction of chronic severe mitral regurgitation confers improved exercise capacity. Reduction of left atrial volume and pulmonary artery pressure may contribute to this improvement.

Diagnosis of rheumatic carditis in Mongolian children

Purpose

The aim of this study was to evaluate the clinical and echocardiographic findings in patients with acute rheumatic fever (ARF) and rheumatic heart diseases (RHD) and to compare echocardiographic findings with the clinical symptoms for the detection of subclinical carditis.

Methods

The study included 156 patients who meet the modified criteria of Jones. M-mode echocardiography was performed using a Sonos-1000 echo machine and 3.5-MHz transducer.

Results

Total of 156 patients with acute RF and RHD (median age 11.9, standard deviation 3.32, range 5–17, male to female ratio 1:1.4) were evaluated. All patients were divided into 2 groups according their diagnosis. The first group included 71 (45.5%) patients with a first onset of rheumatic fever (ARF), the second group—86 (54.5%) patients with a recurrent rheumatic fever (RHD). By echocardiography, 21 (20.1%) patients of first group, who had clinically isolated polyarthritis and chorea were diagnosed a first degree of mitral regurgitation and mitral valve thickening, which is the characteristic finding of rheumatic carditis. Out of all patients, mitral valve regurgitation was detected by 2D echocardiography in 146 (93.5%) patients. The cause of mitral valve regurgitation was annular dilatation in 48%, mitral valve prolapse in 10% and fibrotic change of valve in 42%.

Conclusion

Mitral regurgitation is the most common finding on Doppler color imaging in patients with the rheumatic carditis. In patients clinically manifesting only polyarthritis and/or chorea, we should exclude the subclinical carditis that can be easily detected by echocardiography. The presence of subclinical carditis should be accepted as an evidence of carditis.

European Association of Echocardiography recommendations for the assessment of valvular regurgitation. Part 2: mitral and tricuspid regurgitation (native valve disease)

Mitral and tricuspid are increasingly prevalent. Doppler echocardiography not only detects the presence of regurgitation but also permits to understand mechanisms of regurgitation, quantification of its severity and repercussions. The present document aims to provide standards for the assessment of mitral and tricuspid regurgitation.

Peak systolic velocity of mitral annular longitudinal movement measured by pulsed tissue Doppler imaging as an index of global left ventricular contractility

We sought to test whether the peak systolic velocity of mitral annular longitudinal movement ( S′) measured by pulsed tissue Doppler imaging technique is useful to assess global left ventricular (LV) contractility under various LV inotropic conditions, including regional wall motion abnormality. In addition, the accuracy of S′ relative to LV ejection fraction (EF), a conventional index of LV contractility, and its association with apical rotation, a new index of LV contractility, were also evaluated. We measured S′ at the medial mitral annulus and apical rotation in 11 open-chest anesthetized dogs at eight inotropic stages before and after ligation of either the left anterior descending or circumflex coronary artery. Maximal positive dP/d t (dP/d tpeak) was monitored using a high-fidelity pressure catheter and used as the standard measure of LV contractility. S′ showed dose-dependent increases and decreases after dobutamine and esmolol infusion, respectively. There was a stronger association between dP/d tpeak and S′ ( R2 = 0.665, P < 0.001) than between dP/d tpeak and EF ( R2 = 0.408, P < 0.001), and this trend was more apparent with coronary ligation, regardless of the ligation site. The strength of association between dP/d tpeak and S′ ( R2 = 0.665) was not different from that between dP/d tpeak and apical rotation ( R2 = 0.726) ( P = 0.350). The association between LV EF and S′ was modest ( R2 = 0.472, P < 0.001), whereas a good association between S′ and apical rotation was observed both with ( R2 = 0.552, P < 0.001) and without ( R2 = 0.674, P < 0.001) coronary ligation. S′ is a more sensitive index of global LV contractility than is LV EF, reflecting both LV longitudinal shortening and torsional deformation.

Clinical and functional characterisation of rheumatic mitral regurgitation in children and adolescents including the brain natriuretic peptide

Rheumatic fever is a public health problem of universal distribution, predominantly affecting individuals in developing countries. In individuals less than 20 years of age, pure mitral regurgitation is the most commonly found condition in chronic rheumatic valve disease. In the present study, rheumatic mitral regurgitation was assessed in children and adolescents, addressing its clinical (duration of the disease, symptoms, use of benzathine penicillin, and number of outbreaks of the acute phase of rheumatic fever), electrocardiographic (left atrium abnormality and/or left ventricle hypertrophy) and echocardiographic characteristics (left atrium and ventricle measurements, ejection fraction and pulmonary artery pressure), as well as plasma dose of N-terminal portion of the brain natriuretic peptide through electrochemiluminescence immunoassay. Fifty-three patients were studied. The patients had moderate (41.5%) or severe (58.5%) rheumatic mitral regurgitation; had not undergone surgery; were not in the acute phase of the disease; and were being treated at a paediatric cardiology reference hospital in Northeastern Brazil. Mean patient age was 10.6 years (minimum of 3 and maximum of 19 years). With the exception of the ejection fraction, the echocardiographic variables had a significant correlation to the natriuretic peptide, demonstrating that this hormone reflects the haemodynamic consequences of mitral regurgitation. It was concluded that cardiac remodelling that occurs in rheumatic mitral regurgitation in children and adolescents leads to the production of the brain natriuretic peptide, which could be used as a complementary diagnostic tool in the follow-up of such patients.

Novel methods to assess heart valve disease

Optimal timing of surgery for heart valve disease relies on the accurate assessment of symptoms, lesion severity, cardiac function and the risks of disease progression. Recent studies suggest potential roles for new echocardiographic techniques, including tissue Doppler and strain imaging at rest or after exercise stress, cardiac magnetic resonance imaging and biomarkers such as B-type natriuretic peptide. These techniques may identify patients at higher risk of symptomatic deterioration or adverse clinical events, and improve the cost-effectiveness and reliability of follow-up.

Importance of left ventricular longitudinal function and functional reserve in patients with degenerative mitral regurgitation: assessment by two-dimensional speckle tracking

BACKGROUND

The aim of this study was to determine whether two-dimensional speckle tracking of longitudinal myocardial deformation can detect limited contractile reserve during exercise in patients with asymptomatic degenerative mitral regurgitation (MR).

METHODS

Seventy-one patients with degenerative MR and normal left ventricular (LV) ejection fractions underwent quantitative exercise echocardiography.

RESULTS

Compared with 23 normal subjects matched for age and sex, LV volumes were greater in patients with MR. At rest, global longitudinal strain (GLS) was lower in patients, indicating subclinical LV dysfunction. During exercise, the extent and the magnitude of changes in GLS were larger in controls than in patients with MR. On multivariate regression analysis, left atrial volume at rest and changes in GLS at peak exercise were independently associated with changes in LV ejection fraction.

CONCLUSION

In asymptomatic patients with degenerative MR, subnormal LV function can be reliably identified by two-dimensional strain imaging. Limited exercise LV longitudinal contractile recruitment during exercise predicts postoperative LV dysfunction.

Evaluation of left ventricular short- and long-axis function in severe mitral regurgitation using 2-dimensional strain echocardiography

BACKGROUND

Few data exist on the changes in left ventricular (LV) short- and long-axis function and their usefulness as markers of LV contractile function in patients with chronic, severe mitral regurgitation (MR).

METHODS

We studied 59 patients who had severe MR with an ejection fraction > or =50% and 34 healthy controls. Speckle tracking imaging was performed to measure peak systolic radial (SR(R)), circumferential (SR(C)), and longitudinal strain rates (SR(L)). In all patients, the peak rate of LV pressure rise (peak dP/dt) was measured using a micromanometer-tipped catheter. The patients were subdivided into patients with preserved (group 1, peak dP/dt > or =1,300 mm Hg/s [n = 30]) and depressed (group 2 [n = 29]) contractile function.

RESULTS

SR(L) was significantly depressed in groups 1 and 2 when compared with the control group, but there was no difference between groups 1 and 2. In contrast, SR(R) and SR(C) were depressed only in group 2, whereas there were no differences between the control group and group 1. SR(R) and SR(C) correlated well with peak dP/dt (r = 0.71, P <.001 and r = -0.63, P <.001, respectively), whereas SR(L) did not. These findings suggest that LV long-axis function becomes depressed earlier than short-axis function in the chronic remodeling process.

CONCLUSIONS

Left ventricular short-axis function is a useful marker of LV contractility in patients with chronic, severe MR. Left ventricular long-axis function becomes depressed earlier in the chronic remodeling process. Therefore, evaluation of short-axis as well as long-axis function might be important for better assessment of LV contractile function in these patients.