Restricted diastolic opening of the mitral leaflets in patients with left ventricular dysfunction: evidence for increased valve tethering

Objectives. We tested the hypothesis that patients with incomplete systolic mitral leaflet closure (IMLC: apically displaced coaptation) also have restricted diastolic leaflet opening that is independent of mitral inflow volume and provides evidence supporting increased leaflet tethering.Background. Competing hypotheses for functional mitral regurgitation (MR) with IMLC include global left ventricular (LV) dysfunction per se (reduced leaflet closing force) versus geometric distortion of the mitral apparatus by LV dilation (augmented leaflet tethering). These are inseparable in systole, but restricted leaflet motion has also been observed in diastole, and attributed to reduced mitral inflow.Methods. Diastolic mitral leaflet excursion and orifice area were measured by two-dimensional echocardiography in 58 patients with global LV dysfunction, 36 with and 22 without IMLC, compared with 21 normal subjects. The biplane Simpson’s method was used to calculate LV ejection volume, which equals mitral inflow volume in the absence of aortic regurgitation.Results. The diastolic mitral leaflet excursion angle was markedly reduced in patients with IMLC compared with those without IMLC, whose ventricles were smaller, and normal subjects (17 ± 10° vs. 58 ± 13° vs. 67 ± 8°, p < 0.0001). Excursion angle was dissociated from mitral inflow volume (r²= 0.04); excursion was reduced in patients with IMLC despite a normal inflow volume in the larger ventricles with MR (60 ± 25 vs. 61 ± 12 ml in normal subjects, p = NS), and excursion was nearly normal in patients without IMLC despite reduced inflow volume (40 ± 10 ml, p < 0.001 vs. normal subjects). The anterior leaflet when maximally open coincided well with the line connecting its attachments to the anterior annulus and papillary muscle tip (angular difference = 3 ± 7° vs. 25 ± 9° vs. 32 ± 10° in patients with and without IMLC vs. normal subjects, p < 0.0001). In patients with IMLC, the leaflet tip orifice was smaller in an anteroposterior direction but wider than in the other groups, giving a normal total area (6.8 ± 1.8 vs. 7.1 ± 1.2 vs. 6.9 ± 0.8 cm², p = NS).Conclusions. Patients with LV dysfunction and systolic IMLC also have restricted diastolic leaflet excursion that is independent of inflow volume, coincides with the tethering line connecting the annulus and papillary muscle and reflects limitation of anterior motion relative to the posteriorly placed papillary muscles without a decrease in total orifice area. These observations are consistent with increased tethering by displaced mitral leaflet attachments in the dilated ventricles of patients with IMLC that can restrict both diastolic opening and systolic closure.     

Three-dimensional echocardiographic planimetry of maximal regurgitant orifice area in myxomatous mitral regurgitation: intraoperative comparison with proximal flow convergence

Objectives. We sought to validate direct planimetry of mitral regurgitant orifice area from three-dimensional echocardiographic reconstructions.Background. Regurgitant orifice area (ROA) is an important measure of the severity of mitral regurgitation (MR) that up to now has been calculated from hemodynamic data rather than measured directly. We hypothesized that improved spatial resolution of the mitral valve (MV) with three-dimensional (3D) echo might allow accurate planimetry of ROA.Methods. We reconstructed the MV using 3D echo with 3° rotational acquisitions (TomTec) using a transesophageal (TEE) multiplane probe in 15 patients undergoing MV repair (age 59 ± 11 years). One observer reconstructed the prolapsing mitral leaflet in a left atrial plane parallel to the ROA and planimetered the two-dimensional (2D) projection of the maximal ROA. A second observer, blinded to the results of the first, calculated maximal ROA using the proximal convergence method defined as maximal flow rate (2πr²v_a, where r is the radius of a color alias contour with velocity v_a) divided by regurgitant peak velocity (obtained by continuous wave [CW] Doppler) and corrected as necessary for proximal flow constraint.Results. Maximal ROA was 0.79 ± 0.39 (mean ± SD) cm²by 3D and 0.86 ± 0.42 cm²by proximal convergence (p = NS). Maximal ROA by 3D echo (y) was highly correlated with the corresponding flow measurement (x) (y = 0.87x + 0.03, r = 0.95, p < 0.001) with close agreement seen (ΔROA (y − x) = 0.07 ± 0.12 cm²).Conclusions. 3D echo imaging of the MV allows direct visualization and planimetry of the ROA in patients with severe MR with good agreement to flow-based proximal convergence measurements.     

Echocardiographic prediction of left ventricular function after correction of mitral regurgitation: Results and clinical implications

Objectives. This study attempted to determine the incidence, prognosis and predictability of postoperative left ventricular dysfunction in patients undergoing correction of mitral regurgitation.Background. Left ventricular fonction in patients with mitral regurgitation is altered by loading conditions and is difficult to assess. Predictive value of preoperative variables on postoperative left ventricular function and the role of echocardiography are uncertain.Methods. In 266 patients undergoing correction of mitral regurgitation between 1980 and 1989, left ventricular fonction was echocardiographically assessed preoperatively (within 6 months) and postoperatively (within 1 year).Results. After correction of mitral regurgitation, left ventricular ejection fraction decreased significantly ([mean ± SD] 50% ± 14% vs. 58% ± 13%, p < 0.0001). Postoperative left ventricular dysfunction (ejection fraction < 50%) was frequent (41% of patients) and carried a poor prognosis (at 8 years survival, 38% ± 9% vs. 69% ± 8%, p < 0.0001). Four preoperative echocardiographic variables showed good correlation with postoperative ejection fraction: preoperative ejection fraction (r = −0.70), systolic diameter (r = −0.63), diameter/thickness ratio (r = − 0.64) and end-systolic wall stress (r = −0.62) (all p < 0.0001). With multivariate analysis, ejection fraction (p = 0.0001) and systolic diameter (p = 0.0005) were independent predictors of postoperative ejection fraction, and angiographic variables provided no incremental predictive power. In addition to echocardiographic variables, recent regurgitation, functional class and coronary artery disease were also independent predictors of postoperative ejection fraction.Conclusions. After surgical correction of mitral regurgitation, left ventricular dysfunction is frequent and carries a poor prognosis. Postoperative ejection fraction can be predicted by echocardiographic preoperative ejection fraction and systolic diameter. Recent onset of regurgitation, mild or no symptoms, and absence of coronary artery disease are independent and favorable predictors of postoperative ejection fraction. These results should lead to consideration of surgical correction at an earlier stage.     

Validation of Prosthetic Mitral Regurgitation Quantification Using Novel Angiographic Platform by Mock Circulation

ObjectivesThis study aimed to validate a dedicated software for quantitative videodensitometric angiographic assessment of mitral regurgitation (QMR).BackgroundQuantitative videodensitometric aortography of aortic regurgitation using the time-density principle is a well-documented technique, but the angiographic assessment of mitral regurgitation (MR) remains at best semi-quantitative and operator dependent.MethodsFourteen sheep underwent surgical mitral valve replacement using 2 different prostheses. Pre-sacrifice left ventriculograms were used to assess MR fraction (MRF) using QMR and MR volume (MRV). In an independent core lab, the CAAS QMR 0.1 was used for QMR analysis. In vitro MRF and MRV were assessed in a mock circulation at a comparable cardiac output to the in vivo one by thermodilution. The correlations and agreements of in vitro and in vivo MRF, MRV, and interobserver reproducibility for QMR analysis were assessed using the averaged cardiac cycles (CCs).ResultsIn vivo derived MRF by QMR strongly correlated with in vitro derived MRF, regardless of the number of the CCs analyzed (best correlation: 3 CCs y = 0.446 + 0.994x; R = 0.784; p =0.002). The mean absolute difference between in vitro derived MRF and in vivo derived MRF from 3 CCs was 0.01 ± 4.2% on Bland-Altman analysis. In vitro MRV and in vivo MRV from 3 CCs were very strongly correlated (y = 0.196 + 1.255x; R = 0.839; p < 0.001). The mean absolute difference between in vitro MRV and in vivo MRV from 3 CCs was –1.4 ± 1.9 ml. There were very strong correlations of in vivo MRF between 2 independent analysts, regardless of the number of the CCs.ConclusionsIn vivo MRF using the novel software is feasible, accurate, and highly reproducible. These promising results have led us to initiate the first human feasibility study comprising patients undergoing percutaneous mitral valve edge-to-edge repair.     

Assessment of Mitral Annulus Velocity by Doppler Tissue Imaging in the Evaluation of Left Ventricular Diastolic Function

Objectives. This study assessed the clinical utility of mitral annulus velocity in the evaluation of left ventricular diastolic function.Background. Mitral inflow velocity recorded by Doppler echocardiography has been widely used to evaluate left ventricular diastolic function but is affected by other factors. The mitral annulus velocity profile during diastole may provide additional information about left ventricular diastolic function.Methods. Mitral annulus velocity during diastole was measured by Doppler tissue imaging (DTI) 1) in 59 normal volunteers (group 1); 2) in 20 patients with a relaxation abnormality as assessed by Doppler mitral inflow variables (group 2) at baseline and after saline loading; 3) in 11 patients (group 3) with normal diastolic function before and after intravenous nitroglycerin infusion; and 4) in 38 consecutive patients (group 4) undergoing cardiac catheterization in whom mitral inflow velocity and tau as well as mitral annulus velocity were measured simultaneously.Results. In group 1, mean ± SD peak early and late diastolic mitral annulus velocity was 10.0 ± 1.3 and 9.5 ± 1.5 cm/s, respectively. In group 2, mitral inflow velocity profile changed toward the pseudonormalization pattern with saline loading (deceleration time 311 ± 84 ms before to 216 ± 40 ms after intervention, p < 0.001), whereas peak early diastolic mitral annulus velocity did not change significantly (5.3 ± 1.2 cm/s to 5.7 ± 1.4 cm/s, p = NS). In group 3, despite a significant change in mitral inflow velocity profile after nitroglycerin, peak early diastolic mitral annulus velocity did not change significantly (9.5 ± 2.2 cm/s to 9.2 ± 1.7 cm/s, p = NS). In group 4, peak early diastolic mitral annulus velocity (r = −0.56, p < 0.01) and the early/late ratio (r = −0.46, p < 0.01) correlated with tau. When the combination of normal mitral inflow variables with prolonged tau (≥50 ms) was classified as pseudonormalization, peak early diastolic mitral annulus velocity <8.5 cm/s and the early/late ratio <1 could identify the pseudonormalization with a sensitivity of 88% and specificity of 67%.Conclusions. Mitral annulus velocity determined by DTI is a relatively preload-independent variable in evaluating diastolic function.     

Subclinical left ventricular dysfunction in asymptomatic chronic mitral regurgitation patients with normal ejection fraction: a combined tissue Doppler and velocity vector imaging-based study

Background: The optimal timing of the surgery in asymptomatic severe mitral regurgitation (MR) remains a challenge. The aim of the study is to evaluate the subclinical changes in LV longitudinal functions by using a novel strain imaging technique; velocity vector imaging (VVI); in patients with chronic MR. Methods and Results: We studied 54 patients with asymptomatic, nonischemic, chronic MR (56.8 ± 9 years and 56% male) and 30 healthy controls (55 ± 6.5 years and 55% male) with normal ejection fraction. Patients with MR were analyzed in tertiles according to their regurgitant volumes (RV) and regurgitant fractions (RF): mild MR (RV < 30 mL, RF < 30% n = 7), moderate MR (RV: 30–59 mL, RF = 30–50%; n = 29), and severe MR (RV > 60 mL, RF ≥ 50%; n = 18). Conventional echocardiography and VVI‐based strain imaging were performed to analyze LV functions. LV longitudinal peak systolic strain and strain rate (SRs) were significantly impaired in moderate and severe MR patients. Changes in LV longitudinal deformation were more significant in patients with severe MR. All deformation parameters showed a marked negative correlation with RV (LV Strain r =–0.583, P = 0.0001; LV SR r =–0.408, P = 0.002, respectively). Conclusions: LV long‐axis functions are important markers of LV contractility in MR patients. Novel echocardiographic techniques may provide additional data on subclinical changes in the LV and give way to the optimal timing for the surgery in severe MR patients. (Echocardiography 2011;28:877‐885)     

Exercise-induced changes in mitral regurgitation in patients with prior myocardial infarction and left ventricular dysfunction: relation to mitral deformation and left ventricular function and shape.

AIMS: The aim of this study was to assess the relationship between exercise-induced changes in mitral regurgitation (MR) and echocardiographic characteristics of mitral deformation, global left ventricular (LV) function and shape at rest and after exercise. METHODS AND RESULTS: Forty consecutive patients with ischaemic MR due to prior myocardial infarction (MI), ejection fraction <45% in sinus rhythm underwent exercise-echocardiographic testing. Exercise-induced changes in effective regurgitant orifice (ERO) were compared with baseline and exercise-induced changes in mitral deformation and global LV function and shape. There was significant correlation between exercise-induced changes in ERO and changes in coaptation distance (r=0.80, P<0.0001), tenting area (r=0.79, P<0.0001) and mitral annular diameter (r=0.65, P<0.0001), as well as in end-systolic sphericity index (r=-0.50, P=0.001, respectively), and wall motion score index (r=0.44, P=0.004). In contrast, exercise-induced changes in ERO were not related to the echocardiographic features at rest. By stepwise multiple regression model, the exercise-induced changes in mitral deformation were found to independently correlate with exercise-induced changes in ERO (generalized r(2)=0.80, P<0.0001). CONCLUSION: Exercise-induced changes in severity of ischaemic MR in patients with LV dysfunction due to prior MI were independently related to changes in mitral deformation.     

Limitations of qualitative angiographic grading in aortic or mitral regurgitation

This study was performed to assess the accuracy of qualitative angiographic grading in persons with aortic regurgitation (AR) or mitral regurgitation (MR) and to determine the factors that may influence the reliability of such grading. In 230 patients (152 men, 78 women, aged 52 ± 14 years) with AR or MR, forward cardiac index was measured by the Fick and indicator dilution techniques and left ventricular (LV) angiographic index by the area-length method, from which the regurgitant volume index was calculated. In 124 other patients (89 men, 35 women, aged 52 ± 11 years) without regurgitation, there was good agreement between forward and angiographic cardiac indexes (r = 0.87, p < 0.001). In the 83 patients with AR, the regurgitant volume indexes in those with 1+ (0.87 ± 0.57 liters/min/m²) and 2+ (1.72 ± 1.19 liters/min/m²) angiographic regurgitation were not significantly different from one another, but were significantly different from those with 3+ (3.0 ± 1.42 liters/min/m²) and 4+ (4.80 ± 2.25 liters/min/m²⁺) regurgitation; at the same time, the regurgitant volume indexes of patients with 3+ and 4+ AR were not significantly different from one another. In the 147 patients with MR, the regurgitant volume indexes in patients with 1+ regurgitation (0.61 ± 0.64 liters/min/m²) were significantly lower than other grades, but the regurgitant volume indexes of 2+ (1.14 ± 0.85 liters/min/m²⁺) vs 3+ (2.14 ± 1.37 liters/min/m²) and of 3+ vs 4+ (4.60 ± 2.31 liters/min/m²⁺) were not significantly different. With AR and MR, regurgitant flow within each angiographic grade varied widely, especially in grades 3+ and 4+, and there was considerable overlap of regurgitant volume indexes between grades. In patients with an LV end-diastolic volume index ≥ 120 ml/m², the angiographic grading of regurgitation was particularly likely to underestimate the regurgitant volume index. At the same time, the reliability of angiographic grading was not influenced by an enlarged LV end-systolic volume index, a depressed LV ejection fraction, a low forward cardiac index, or an elevated LV end-diastolic or pulmonary capillary wedge pressure. Thus, in patients with AR or MR, the angiographic grading of regurgitation often is at variance with the measured regurgitant volume index, especially in patients with enlarged left ventricles.     

The echocardiographic determinants of functional mitral regurgitation differ in ischemic and non-ischemic cardiomyopathy

BACKGROUND: Functional mitral regurgitation (MR) is one of the common and severe complications in patients with dilated cardiomyopathy. The detailed mechanisms that cause functional MR remain to be elucidated. Using two-dimensional transthoracic echocardiography, we investigated the differences in major determinants of MR severity between ischemic cardiomyopathy (ICM) and non-ICM patients. METHODS: We enrolled 103 patients (91 males; age 64+/-12 years) with significant left ventricular (LV) dilatation. They were divided into ICM group (n=69) with significant coronary disease, and non-ICM (n=34) group without coronary disease. We devised a novel and simple parameter; the short-axis sphericity index (SI), to evaluate global LV remodeling, and used coaptation depth (CD) and tenting area (TA) to evaluate mitral deformity. RESULTS: In all cases, CD, TA and left atrium diameter (LAD) correlated positively with maximum regurgitation area (MRA) (r=0.54, 0.57, 0.57; P<0.0001). A negative correlation was observed between MRA and SI (r=-0.33, P=0.0008). There was no significant relationship between MRA and LV ejection fraction (EF). In non-ICM cases, SI tended to be lower with reduced EF. Multivariate stepwise linear regression analysis showed the following equations; ICM: MRA=-9.4+0.81CD+0.21LAD (r2=0.47, P<0.0001), non-ICM: MRA=-7.2+0.17LVDs (LV end systolic diameter) -8.7SI+0.27LAD (r2=0.63, P<0.0001). CONCLUSIONS: The strongest determinants of functional MR severity differ in ICM and non-ICM. While LV diameter and SI (global LV remodeling index) mainly determine the severity in non-ICM, CD that reflects mitral deformity is the major determinant in ICM.     

Quantification of mitral regurgitation by Doppler color flow mapping: comparison of mitral regurgitant fraction and volume with Doppler measurements]

Color flow imaging of the regurgitant areas has been used to quantitate the severity of valvular regurgitation, however, the exact relationship between color flow areas and regurgitant volumes or fraction has not been clarified. This study was designed to determine whether measurements of jet flow areas and distances using color flow imaging are closely related to the regurgitant volume (MRV:ml/beat) and fraction (MRF: %). Doppler examinations were performed in 29 patients with mitral regurgitation (MR). The MR jet was depicted as the largest clearly definable flow disturbance on the echo images, and the maximal jet area (cm2) and length (cm) were measured. The MRV and MRF were obtained from the Doppler measurements of the transmitral flow (TMF) and the aortic flow (AF) as follows: MRV = TMF-AF, MRF = MRV/TMF x 100. The maximal jet area showed significant correlations with the MRV and MRF (r = 0.75 and 0.75, p < 0.01), and the maximal jet length showed even better correlations with the MRV and MRF (r = 0.82 and 0.80, p < 0.01), irrespective of the etiology of MR. Thus, both the maximal jet area and length obtained from color flow imaging can be simple and useful measurement methods for predicting the MRV and MRF.     

Left ventricular response to isometric exercise and its value in predicting the change in ventricular function after mitral valve replacement for mitral regurgitation

Reduced left ventricular (LV) afterload and its effect on the resting ejection fraction may lead to over-estimation of LV function in mitral regurgitation (MR). To evaluate LV function during increased afterload of the heart, an isometric handgrip test was performed during cardiac catheterization in 15 patients with mitral regurgitation (MR group) and in 9 normal subjects (normal group). Twelve months after successful mitral valve replacement (MVR) the patients were recatheterized, and the value of preoperative stress testing in predicting the change in resting ventricular function after surgery was estimated.Isometric exercise caused an increase in end-systolic wall stress, a measure of ventricular afterload, in both the MR group and the control group (p < 0.001). The ejection fraction remained unchanged in the control group, but decreased from 0.58 ± 0.08 to 0.53 ± 0.08 in the MR group (p < 0.001). After MVR, end-systolic wall stress increased significantly (p < 0.001) and the ejection fraction decreased from 0.58 ± 0.05 to 0.51 ± 0.1 (p < 0.05). A positive correlation existed between the change in the ejection fraction during preoperative stress testing and the change in the resting ejection fraction after MVR (r = 0.65, p < 0.01). In 8 patients whose resting ejection fraction was within normal limits (> 0.55) preoperatively, the ejection fraction was depressed (< 0.55) 1 year after surgery. In all but 1 of these patients the isometric exercise revealed the reduced ventricular response to afterload stress preoperatively (decrease of the ejection fraction > 0.03 during exercise). Therefore, the isometric exercise-induced change in LV function appears to predict the influence of MVR on LV function.     

High levels of high-sensitivity C-reactive protein and uric acid can predict disease severity in patients with mitral regurgitation

IntroductionBoth high-sensitivity CRP (hs-CRP) and uric acid (UA) levels are known to be increased in heart failure patients and are associated with poorer functional capacity and adverse outcome. The role of these markers in patients with mitral regurgitation (MR) is less clear. The aim of this study was to assess the relationship between hs-CRP, UA and organic MR. We also assessed whether hs-CRP and UA levels are correlated with symptoms of MR, severity of MR, LV remodeling and outcome during follow-up.MethodsA total of 200 consecutive patients (87 men [43.5%]; mean age 61.6±12.5 years) with moderate or severe isolated and organic MR were included in the study. All the patients were assessed clinically and were managed and treated with standard medical therapy according to evidence-based practice guidelines. Patients were categorized according to New York Heart Association (NYHA) functional class. We assessed and graded the severity of MR using a multiparametric approach. hs-CRP was measured with chemiluminescent immunometric assay using an IMMULITE^® 1000 autoanalyzer (Siemens, Germany). Serum UA levels were analyzed using a Cobas^® 6000 autoanalyzer (Roche Diagnostics, Mannheim, Germany).ResultsMean UA levels increased significantly with NYHA class: 4.46±1.58 mg/dl for patients in NYHA class I, 5.91±1.69 mg/dl for class II, 6.31±2.16 mg/dl for class III and 8.86±3.17 mg/dl for class IV (p<0.001). Mean UA levels also increased significantly with increased severity of MR (moderate 5.62±1.9 mg/dl, moderate to severe 5.56±1.2 mg/dl, severe 7.38±3.4 mg/dl, p<0.001). There was a significant correlation between UA level and left ventricular end-diastolic diameter (r=0.40; p<0.001), left ventricular end-systolic diameter (r=0.297; p=0.001) and left ventricular ejection fraction (LVEF) (r=0.195, p=0.036), whereas hs-CRP was not correlated with these parameters. In multivariate Cox proportional hazards analysis LVEF, NYHA class and UA levels were the only independent predictors of death.ConclusionUA and hs-CRP levels can help identify patients with asymptomatic moderate or severe mitral regurgitation. UA levels may be useful to assess the extent of left ventricular remodeling and in the optimal timing of mitral valve surgery in certain subsets of patients.     

Feasibility of tissue magnetic resonance imaging: a pilot study in comparison with tissue Doppler imaging and invasive measurement

OBJECTIVES: This research was intended to determine the feasibility of tissue magnetic resonance (MR) imaging in comparison with tissue Doppler imaging and its potential implications for the estimation of filling pressure, in comparison with invasive measurement. BACKGROUND: Evaluation of diastolic function using MR imaging is commonly confined to the study of transmitral flow. However, transmitral flow is unreliable for the estimation of left ventricular (LV) filling pressures in hypertrophy and normal systolic function. Normalizing early mitral velocity (E) for the influence of myocardial relaxation by combining E with early diastolic mitral septal tissue velocity (Ea) provides better Doppler estimates of filling pressures. METHODS: Eighteen patients with hypertensive heart disease (LV mass index: 114 +/- 21 g/m(2)), absence of valvular regurgitation, and with normal or mildly reduced systolic function (LV ejection fraction: 57.6 +/- 6.5%) referred for cardiac catheterization, underwent consecutive measurement of mitral flow and septal tissue velocities with phase-contrast MR and Doppler. These data were compared with mean pulmonary capillary wedge pressure (PCWP). RESULTS: There was a strong relation between MR (11.6 +/- 4.3) and Doppler-assessed (12.1 +/- 3.5) E/Ea (95% confidence interval of -1.5 to 0.5) (r = 0.89, p < 0.0001). In addition, E/Ea related strongly to invasively measured PCWP (MR: r = 0.80, p < 0.0001 and Doppler: r = 0.85, p < 0.0001). CONCLUSIONS: Tissue MR imaging is a feasible method to assess Ea. Combining E and Ea allowed similar estimation of filling pressure by MR and Doppler, in good agreement with invasive measurement. The potential confounding effect of valvular regurgitation needs further study.     

Non-invasive measurement of the regurgitant fraction by pulsed Doppler echocardiography in isolated pure mitral regurgitation.

OBJECTIVE--To assess the usefulness of pulsed Doppler echocardiography as a method of measuring the regurgitant fraction in patients with mitral regurgitation. PATIENTS AND METHODS--Twenty controls and 27 patients with isolated mitral regurgitation underwent Doppler studies. In the patients the study was performed within 48 hours of cardiac catheterisation. Aortic outflow was measured in the centre of the aortic annulus, and mitral inflow was derived from the flow velocity at the tip of the leaflets and the area of the elliptical mitral opening. The regurgitant fraction was calculated as the difference between the two flows divided by the mtiral inflow. RESULTS--In the 20 controls the two flows were almost identical (mitral inflow, 4.44 (SD 0.88) l/min; aortic outflow, 4.58 (SD 0.84) l/min), with a mean regurgitant fraction of 4.2 (SD 8.4)%. In patients with mitral regurgitation, the mitral inflow was significantly higher than the aortic outflow (8.8 (3.6) v 4.3 (1.1) l/min). In most patients the Doppler-derived regurgitant fraction (45.8 (19.2)%) accorded closely with the regurgitant fraction (41.3 (SD 17.8)%) determined by the haemodynamic technique. CONCLUSION--Pulsed Doppler echocardiography, with an instantaneous velocity-valve area method for calculating mitral inflow, reliably measured the severity of regurgitation in patients with mitral regurgitation.     

Three-Dimensional Echocardiographic Reconstruction of the Left Ventricle by a Transesophageal Tomographic Technique

Accurate determination of left ventricular (LV) volume has important therapeutic and prognostic implications in patients with cardiac disease. Volume estimations by two-dimensional techniques are not very accurate due to geometric assumptions. Objectives: To validate LV volume determinations by a new transesophageal three-dimensional echocardiographic technique. We performed three-dimensional reconstruction of the LV using an echo-computed tomographic (CT) technique based on serial pullback parallel slice imaging technique in both in vitro and in vivo settings. Fourteen latex-balloons with various sizes (30–235 mL) and shapes (conical, pear shaped, round, elliptical, and aneurysms in various locations) filled with known volumes of water were imaged in a water bath. From the static three-dimensional image, the LV long axis was defined and the LV was sectioned perpendicular to this axis into 2-mm slices. The volume of each slice was calculated with the observer blinded to the actual volume as the product of the slice thickness and the manually traced perimeter of the slice and the LV volume as the sum of the volumes of the slices (Simpson's method). The calculated LV volume closely correlated with the actual volume (r = 0.99, P < 0.0001, calculated volume = 1.06x – 11.3, Δvolume =-5.7 ± 10.0 cc). Using the same system, transesophageal echocardiographic (TEE) images of the LV were obtained in 15 patients gated to respiration and ECG. Satisfactory dynamic three-dimensional reconstruction of the LV was possible in ten patients. The three-dimensional LV volumes (systolic and diastolic) using Simpson's method correlated well with those obtained from biplane or multiplane TEE images using the area length method (r = 0.89, P < 0.0001, y = 12.7 + 0.84x, Δvolume = 1.3 ± 18.1 cc). The LV major-axis diameters by the two methods showed very close correlations as well (r = 0.86, P < 0.0001, y = 19 + 0.74x, Δdiameter = 1.0 ± 7.2 mm). We conclude that three-dimensional LV volume calculation by the echo-CT technique is intrinsically sound, is independent of LV geometry, and with some limitations, is applicable in vivo.     

Aortic stiffness: an old concept for new insights into the pathophysiology of functional mitral regurgitation

Functional mitral regurgitation (FMR) is thought to be linked with ventricular afterload. However, the relation between aortic stiffness, which is a main determinant of ventricular afterload, and quantitatively assessed mitral regurgitation is unknown. A total of 175 patients (age 61 ± 13; 85 % male) with left ventricular (LV) systolic dysfunction were studied consecutively. Left ventricular volumes, ejection fraction, and LV outflow tract stroke volume were measured. Aortic pulse wave velocity (PWV), a known marker of aortic stiffness, was determined using Doppler flow recordings as the distance (d) traveled by the pulse wave, measured over the body surface as the distance between the two recording sites, divided by the time (t) taken by the pulse wave to travel from the descending aorta to the abdominal aorta. Mitral effective regurgitant orifice (ERO), regurgitant volume (RV), and fraction (RF) were measured using the proximal isovelocity surface area method. The mean PWV was 6.0 ± 3.5 m/s (range 2.6–25). PWV was significantly associated with ERO (r = 0.35; p < 0.0001), RV (r = 0.36; p < 0.0001) RF (p = 0.41; p < 0.0001). The association of PWV with each variable of mitral regurgitation was independent of LV volume, cardiac output, and systemic vascular resistance. Aortic stiffness is an important determinant of the severity of FMR. Aortic stiffness should be considered an important therapeutic target in patients with LV dysfunction in order to ameliorate both LV systolic and diastolic function and mitral regurgitation.     

Left Ventricular Untwisting in Restrictive and Pseudorestrictive Left Ventricular Filling: Novel Insights into Diastology

Background: Conceptually, an ideal therapeutic agent should target the underlying mechanisms that cause left ventricular (LV) diastolic dysfunction. The objective of our study was to gain further insight into the mechanics of diastology by comparison of LV untwisting measured by speckle tracking echocardiography (STE) in young healthy adults with normal and “pseudorestrictive” LV filling, and dilated cardiomyopathy (DCM) patients with “true restrictive” LV filling. Methods: The study comprised 20 healthy volunteers with a Doppler LV‐inflow pattern compatible with restrictive LV filling but a diastolic early phase filling velocity/early diastolic velocity of the mitral annulus (E/Em) ratio <8 (“pseudorestrictive”), 20 for age and gender‐matched healthy volunteers with normal LV filling and an E/Em ratio <8, and 10 DCM patients with “true restrictive” LV filling and an E/Em ratio >15. LV untwisting parameters were determined by STE. Results: Compared to healthy subjects, DCM patients had decreased peak diastolic untwisting velocity (−62 ± 33 degrees/s vs −113 ± 25 degrees/s, P < 0.01) and untwisting rate (−15 ± 9 degrees/s vs −51 ± 24 degrees/s, P < 0.01). Compared to healthy subjects with normal LV filling, healthy subjects with “pseudorestrictive” LV filling had increased peak diastolic untwisting velocity (−123 ± 25 degrees/s vs −104 ± 30 degrees/s, P < 0.05) and untwisting rate (−59 ± 23 degrees/s vs −44 ± 22 degrees/s, P < 0.05). Conclusion: Faster LV untwisting plays a pivotal role in the rapid early diastolic filling occasionally seen in young healthy individuals. In contrast, in DCM patients untwisting is severely delayed and this impairment to utilize suction may reduce LV filling. (Echocardiography 2010;27:269‐274)     

Non-invasive measurement of the regurgitant fraction by pulsed Doppler echocardiography in isolated pure mitral regurgitation.

OBJECTIVE--To assess the usefulness of pulsed Doppler echocardiography as a method of measuring the regurgitant fraction in patients with mitral regurgitation. PATIENTS AND METHODS--Twenty controls and 27 patients with isolated mitral regurgitation underwent Doppler studies. In the patients the study was performed within 48 hours of cardiac catheterisation. Aortic outflow was measured in the centre of the aortic annulus, and mitral inflow was derived from the flow velocity at the tip of the leaflets and the area of the elliptical mitral opening. The regurgitant fraction was calculated as the difference between the two flows divided by the mtiral inflow. RESULTS--In the 20 controls the two flows were almost identical (mitral inflow, 4.44 (SD 0.88) l/min; aortic outflow, 4.58 (SD 0.84) l/min), with a mean regurgitant fraction of 4.2 (SD 8.4)%. In patients with mitral regurgitation, the mitral inflow was significantly higher than the aortic outflow (8.8 (3.6) v 4.3 (1.1) l/min). In most patients the Doppler-derived regurgitant fraction (45.8 (19.2)%) accorded closely with the regurgitant fraction (41.3 (SD 17.8)%) determined by the haemodynamic technique. CONCLUSION--Pulsed Doppler echocardiography, with an instantaneous velocity-valve area method for calculating mitral inflow, reliably measured the severity of regurgitation in patients with mitral regurgitation.     

Comparison of myocardial performance index obtained either by conventional echocardiography or tissue Doppler echocardiography in healthy subjects and patients with heart failure

This study was planned to investigate the normal reference values of myocardial performance index (MPI) obtained by tissue Doppler echocardiography (TDE) and the agreement between MPI measured by TDE and conventional MPI measured by pulsed-wave Doppler (PWD) in healthy subjects and patients with heart failure (HF). Two hundred and three patients with HF and 190 healthy subjects were enrolled in this study. Isovolumic contraction and relaxation time (ICT and IRT) and ejection time (ET) were measured from mitral inflow and left ventricular (LV) outflow. Tissue Doppler echocardiography recordings were obtained at the septal, lateral, inferior, and anterior of the mitral annulus and same time intervals were measured. Myocardial performance index was calculated. The functional capacity of the patients with HF was determined according to New York Heart Association classification. TDE-MPI values were higher than conventional PWD-MPI values in both groups (53% ± 8% vs 48% ± 11%, P < 0.0001 in the healthy subjects; 84% ± 21% vs 72% ± 19%, P <0.0001 in the patients with HF). Moderate agreement was found between PWD-MPI and LV mean TDE-MPI in both groups. In identifying patients with moderately or severely decreased LV ejection fraction, TDE-MPI had higher cutoff values than conventional PWD-MPI, and TDE-MPI had higher specificity, sensitivity, negative predictive value, and diagnostic accuracy. In patients with HF, TDE-MPI had a stronger correlation with LV ejection fraction and functional capacity than did PWD-MPI. TDE-MPI is an alternative to conventional PWD-MPI in assessment of cardiac function. However, the higher MPI cutoff points should be considered when this method is used for the evaluation of cardiac function.     

Quantification of mitral regurgitation orifice area by 3-dimensional echocardiography: comparison with effective regurgitant orifice area by PISA method and proximal regurgitant jet diameter

BACKGROUND: The evaluation of mitral regurgitation (MR) by 3-dimensional (3D) echo has generally been performed by reconstruction of Doppler regurgitant jets but there are little data on measuring anatomic regurgitant orifice area (AROA) directly from 3D mitral valve (MV) reconstructions. METHODS AND RESULTS: Transoesophageal echo (TOE) 3D images were acquired from 38 unselected patients (age 59+/-11 years, ten in atrial fibrillation) with various degrees of MR. In all patients MV was reconstructed en face from the left atrium (LA) and the left ventricle (LV). AROA was measured by planimetry from 3D pictures and compared to the effective regurgitant orifice area (EROA) by proximal isovelocity surface area and proximal MR jet width from 2D echo. AROA was measured in 95% of patients from LA, 89% from LV and in 84% from both LA and LV. Good correlation was found between EROA and AROA measured from both LA (r=0.97, P<0.0001) and LV (r=0.87, P<0.0001). The mean difference between LA-AROA and EROA was -3.01+/-6.12 mm(2) and -7.18+/-13.84 mm(2) for LV-AROA (P<0.01, respectively). An acceptable correlation was found between the proximal MR jet width and AROA from LA (r=0.71, P<0.0001) and LV perspective (r=0.68, P<0.0001). AROA>or=25 mm(2) differentiated mild MR (graded 1-2) from moderately severe (graded 3-4) with 80-90% accuracy. CONCLUSIONS: 3D TOE provides important quantitative information on both the mechanism and the severity of MR in an unselected group of patients. AROA enables quantification of MR with excellent agreement with the accepted clinical method of proximal flow convergence.