Usefulness of peak mitral inflow velocity to predict severe mitral regurgitation in patients with normal or impaired left ventricular systolic function

Quantification of primary mitral regurgitation by echocardiography: A practical appraisal

The accurate quantification of primary mitral regurgitation (MR) and its consequences on cardiac remodeling is of paramount importance to determine the best timing for surgery in these patients. The recommended echocardiographic grading of primary MR severity relies on an integrated multiparametric approach. It is expected that the large number of echocardiographic parameters collected would offer the possibility to check the measured values regarding their congruence in order to conclude reliably on MR severity. However, the use of multiple parameters to grade MR can result in potential discrepancies between one or more of them. Importantly, many factors beyond MR severity impact the values obtained for these parameters including technical settings, anatomic and hemodynamic considerations, patient's characteristics and echocardiographer' skills. Hence, clinicians involved in valvular diseases should be well aware of the respective strengths and pitfalls of each of MR grading methods by echocardiography. Recent literature highlighted the need for a reappraisal of the severity of primary MR from a hemodynamic perspective. The estimation of MR regurgitation fraction by indirect quantitative methods, whenever possible, should be central when grading the severity of these patients. The assessment of the MR effective regurgitant orifice area by the proximal flow convergence method should be used in a semi-quantitative manner. Furthermore, it is crucial to acknowledge specific clinical situations in MR at risk of misevaluation when grading severity such as late-systolic MR, bi-leaflet prolapse with multiple jets or extensive leak, wall-constrained eccentric jet or in older patients with complex MR mechanism. Finally, it is debatable whether the 4-grades classification of MR severity would be still relevant nowadays, since the indication for mitral valve (MV) surgery is discussed in clinical practice for patients with 3+ and 4+ primary MR based on symptoms, specific markers of adverse outcome and MV repair probability. Primary MR grading should be seen as a continuum integrating both quantification of MR and its consequences, even for patients with presumed “moderate” MR.

Epidemiology of heart disease in English Bull Terriers and echocardiographic characteristics of mitral valve abnormalities

OBJECTIVES

To present the prevalence and distribution of heart disease as well as echocardiographic findings in English Bull Terriers.

MATERIALS AND METHODS

One hundred and one English Bull Terriers were retrospectively included to evaluate the prevalence and distribution of heart disease. Secondly, a retrospective study on mitral valve abnormalities was performed on three groups: a control group (n=120, 19 breeds) used to establish reference intervals for mean transmitral gradient; a healthy English Bull Terriers group (n=25) and an English Bull Terriers group with mitral valve abnormalities (n= 18). Healthy English Bull Terriers for which mitral inflow parameters were not obtainable and English Bull Terriers with other types of heart disease were excluded.

RESULTS

The prevalence of heart disease in English Bull Terriers was 65% (66/101), with mitral valve abnormalities (47%, 47/101) and aortic stenosis (29%, 29/101) being most common. The cut-off value for normal mean transmitral gradient was 3.5 mmHg in the control group. The mean transmitral gradient for healthy English Bull Terriers was higher than for other dog breeds. Healthy English Bull Terriers had a smaller mitral valve area and mitral annulus diameter compared with dogs with a similar body surface area. A high heart rate, smaller mitral valve area, mitral regurgitation, and volume overload are associated with increased mean transmitral gradient in English Bull Terriers with mitral valve abnormalities.

CLINICAL SIGNIFICANCE

We suggest that mitral valve area, mitral annulus diameter and mean transmitral gradient measurements should be included in the echocardiographic protocol for English Bull Terriers.

Computational fluid dynamics modelling of left valvular heart diseases during atrial fibrillation

BACKGROUND

Although atrial fibrillation (AF), a common arrhythmia, frequently presents in patients with underlying valvular disease, its hemodynamic contributions are not fully understood. The present work aimed to computationally study how physical conditions imposed by pathologic valvular anatomy act on AF hemodynamics.

METHODS

We simulated AF with different severity grades of left-sided valvular diseases and compared the cardiovascular effects that they exert during AF, compared to lone AF. The fluid dynamics model used here has been recently validated for lone AF and relies on a lumped parameterization of the four heart chambers, together with the systemic and pulmonary circulation. The AF modelling involves: (i) irregular, uncorrelated and faster heart rate; (ii) atrial contractility dysfunction. Three different grades of severity (mild, moderate, severe) were analyzed for each of the four valvulopathies (AS, aortic stenosis, MS, mitral stenosis, AR, aortic regurgitation, MR, mitral regurgitation), by varying-through the valve opening angle-the valve area.

RESULTS

Regurgitation was hemodynamically more relevant than stenosis, as the latter led to inefficient cardiac flow, while the former introduced more drastic fluid dynamics variation. Moreover, mitral valvulopathies were more significant than aortic ones. In case of aortic valve diseases, proper mitral functioning damps out changes at atrial and pulmonary levels. In the case of mitral valvulopathy, the mitral valve lost its regulating capability, thus hemodynamic variations almost equally affected regions upstream and downstream of the valve. In particular, the present study revealed that both mitral and aortic regurgitation strongly affect hemodynamics, followed by mitral stenosis, while aortic stenosis has the least impact among the analyzed valvular diseases.

DISCUSSION

The proposed approach can provide new mechanistic insights as to which valvular pathologies merit more aggressive treatment of AF. Present findings, if clinically confirmed, hold the potential to impact AF management (e.g., adoption of a rhythm control strategy) in specific valvular diseases.

Reduction in mitral regurgitation during therapy guided by measured filling pressures in the ESCAPE trial

BACKGROUND

Dynamic mitral regurgitation (MR) contributes to decompensation in chronic dilated heart failure. Reduction of MR was the primary physiological end point in the ESCAPE trial, which compared acute therapy guided by jugular venous pressure, edema, and weight (CLIN) with therapy guided additionally by pulmonary artery catheters (PAC) toward pulmonary wedge pressure

METHODS AND RESULTS

Patients were randomized to PAC or CLIN during hospitalization with chronic heart failure and mean left ventricular ejection fraction 20%, and at least 1 symptom and 1 sign of congestion. MR and mitral flow patterns, measured blinded to therapy and timepoint, were available at baseline and discharge in 133 patients, and at 3 months in 104 patients. Changes in MR and related transmitral flow patterns were compared between PAC and CLIN patients. Jugular venous pressure, edema, and weights decreased similarly during therapy in the hospital for both groups. In PAC but not in CLIN patients, MR jet area, MR/left atrial area ratio, and E velocity were each significantly reduced and deceleration time increased by discharge. By 3 months, patients had clinical evidence of increased jugular venous pressure, edema, and weight since discharge, reaching significance in the PAC arm, and the change in MR was no longer different between the 2 groups, although the change in E velocity remained greater in PAC patients.

CONCLUSIONS

During hospitalization, therapy guided by PAC to reduce left-sided pressures improved MR and related filling patterns more than therapy guided clinically by evidence of systemic venous congestion. This early reduction did not translate into improved outcomes out of the hospital, where volume status reverted toward baseline.

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Key Words

• hemodynamics
• heart failure
• cardiomyopathy
• mitral regurgitation

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MESH Headings

• Adult
• Aged
• Body Weight
• Catheterization, Swan-Ganz
• Central Venous Pressure
• Chronic Disease
• Edema/etiology
• Edema/physiopathology
• Edema/therapy
• Female
• Heart Failure/etiology
• Heart Failure/physiopathology
• Heart Failure/therapy
• Hemodynamics
• Hospitalization
• Humans
• Jugular Veins/physiopathology
• Male
• Middle Aged
• Mitral Valve Insufficiency/complications
• Mitral Valve Insufficiency/physiopathology
• Mitral Valve Insufficiency/therapy
• Patient Discharge
• Predictive Value of Tests
• Pulmonary Artery/physiopathology
• Pulmonary Wedge Pressure
• Stroke Volume
• Time Factors
• Treatment Outcome
• United States
• Ventricular Function, Left

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Grants

• N01HV98177 NHLBI NIH HHS
• R01 HL067691 NHLBI NIH HHS
• R01 HL067691-01 NHLBI NIH HHS
• N01-HV-98177 NHLBI NIH HHS

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Affiliation(s)

Maryse Palardy Brigham and Women's Hospital, Boston, Mass; Duke Medical Center, Durham, NC, USA
Lynne W Stevenson
Gudaye Tasissa
Michele A Hamilton
Robert C Bourge
Thomas G Disalvo
Uri Elkayam
James A Hill
Sharon C Reimold

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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%.

What does transesophageal echocardiography add to valvular heart surgery?

No single monitoring tool in the last decade has had more of an effect on intraoperative decision making and surgical management of cardiac valvular pathologies than has TEE. It has become the standard of care for evaluating reparative valvular procedures, thus providing an immediate gauge of the surgical results and helping to avoid suboptimal surgical outcomes. As the technology of TEE and its application advance, so too should the ability to diagnose and manage valvular pathologies, broaden the range of surgical options, and ultimately improve patient outcomes.