Shape Of Left Ventricle Research Articles

STUDY ON THE CORRELATION BETWEEN PLASMA NT-PROBNP CONCENTRATION AND STRUCTURAL CHANGE AND DYSFUNCTION OF LEFT VENTRICLE IN DIABETIC TYPE 2 PATIENTS

Objectives: 1.To measure plasma NT- proBNP levels, shape and function of left ventricle of diabetic type 2 patients, and (2) To explore the correlation between plasma NT-proBNP levels and the shape and function of the left ventricle, and heart failure according to Framingham, NYHA, and ACC/AHA criteria. Materials and Methods: Cross-sectional and descriptive study on 104 diabetic type 2 patients through the measurements of plasma NT-proBNP levels, ECG and Doppler echocardiography. Results: Average plasma NT-proBNP level: 142.17 ± 186.95 pg/ml. The results highlighted that: (1) Plasma NT-proBNP level significantly increases with age, the detection time, the severity of clinical heart failure, left ventricle hypertrophy, and diastolic-systolic dysfunction of left ventricle (p <0.05), and (2) Plasma NT-proBNP level significantly correlates with heart failure based on Framingham criteria (r = 0.66; p < 0.001), functional heart failure based on NYHA classification (r = 0.676; p < 0.001), the stage of heart failure based on the ACC/AHA guidelines (r = 0.709; p < 0.001), left ventricle hypertrophy based on Sokolow-Lyon (r = 0.346; QTc (r = 0.471; p < 0.001), LVMI (r = 0,701; p < 0,001), diastolic dysfunction grades (r = 0.604; p < 0.001), DTE (r = 0.437; p < 0.001), IVRT (r = 0.29; p = 0.003), EF (r = - 0.414; p < 0.001), and systolic dysfunction grades (r = 0.502; p < 0.001). Conclusion : At the cut-point of 125 pg/ml, plasma NT-proBNP level has the prognostic value of left ventricle hypertrophy, and diastolic-systolic dysfunction of left ventricle in diabetic type 2 patients.

A bovine pericardium rigid prosthesis for left ventricle restoration: 12 years of follow-up

Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7% vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ± 20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10%, 11 to 49% and higher than 50% expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.

A geometrical approach for evaluating left ventricular remodeling in myocardial infarct patients

A computational method for quantifying left ventricle (LV) remodeling using 3D mesh models reconstructed from magnetic resonance imaging is proposed. The underlying geometry of the LV mesh is obtained by using a quadric fitting method, and its quantification is performed by using a curvedness shape descriptor. To achieve robustness, we have performed detailed studies of the effects of n-ring parameter selection on the accuracy of this method with in vitro and in vivo LV models. We have found that curvedness calculations based on a 5-ring selection can accurately depict anomalies in LV shape despite the presence of noise due to manual image segmentation. Our studies show that patients after myocardial infarction exhibit significant LV shape alteration in terms of curvedness, in particular at the apex. The diastole-to-systole change in regional curvedness was significantly lower suggesting regional differences in hypokinesis due to infarcted myocardium. This approach may add new insights into ventricular deformation and enable better discrimination between normal and pathologic conditions.

Impact of surgical ventricular restoration on ventricular shape, wall stress, and function in heart failure patients

Surgical ventricular restoration (SVR) was designed to treat patients with aneurysms or large akinetic walls and dilated ventricles. Yet, crucial aspects essential to the efficacy of this procedure like optimal shape and size of the left ventricle (LV) are still debatable. The objective of this study is to quantify the efficacy of SVR based on LV regional shape in terms of curvedness, wall stress, and ventricular systolic function. A total of 40 patients underwent magnetic resonance imaging (MRI) before and after SVR. Both short-axis and long-axis MRI were used to reconstruct end-diastolic and end-systolic three-dimensional LV geometry. The regional shape in terms of surface curvedness, wall thickness, and wall stress indexes were determined for the entire LV. The infarct, border, and remote zones were defined in terms of end-diastolic wall thickness. The LV global systolic function in terms of global ejection fraction, the ratio between stroke work (SW) and end-diastolic volume (SW/EDV), the maximal rate of change of pressure-normalized stress (dσ*/dt(max)), and the regional function in terms of surface area change were examined. The LV end-diastolic and end-systolic volumes were significantly reduced, and global systolic function was improved in ejection fraction, SW/EDV, and dσ*/dt(max). In addition, the end-diastolic and end-systolic stresses in all zones were reduced. Although there was a slight increase in regional curvedness and surface area change in each zone, the change was not significant. Also, while SVR reduced LV wall stress with increased global LV systolic function, regional LV shape and function did not significantly improve.

087 Left ventricle shape and trabeculations in idiopathic dilated cardiomyopathy assessed by cardiac magnetic resonance imaging

Idiopathic dilated cardiomyopathies (IDC) frequently develop left ventricle (LV) hypertrabeculation which bring to doubt about the diagnostic of LV non compaction (LVNC). The high spatial resolution of cardiac magnetic resonance imaging (CMR) allows distinguishing myocardial trabeculations explaining the exponential rise in the number of reports describing LVNC. To study the correlation between the LV shape and myocardial trabeculations regarding the BNP level in a population of IDC. Between November 2007 and November 2009, 48 IDC were prospectively assessed by CMR. Patients with echocardiographic LV ejection fraction (LVEF) > 45%, severe valvulopathy or usual criteria of LVNC were excluded. Patients with significant coronary artery disease (coronary stenosis > 50%) at the angiogram or subendocardium gadolinium delayed enhancement at the CMR were considered as ischemic cardiomyopathy and were excluded. LV end-diastolic volume (EDV) and end-systolic volume were measured by summing cine-CMR LV short axis slice. Sphericity index (SI) was defined as the ratio of LV end-diastolic diameter (EDD) on LV length measured respectively in midventricular short axis and midventricular 4 chambers cine-CMR views. LV trabeculation index (LVTI) was defined as the ratio of trabeculated on compacted layers thickness in a 16-segment model excluding apex. BNP was measured for each patient. Mean age was 52 ± 14 years with 29 (60%) men. Mean LVEF was 25 ± 10% with a mean indexed EDD of 37 ± 5 mm/m 2 and EDV of 135 ± 45 ml/m 2 . LVTI was not correlate with indexed EDV (r = 0.14; p = 0.34) and LVEF (r = 0.02, p = 0.9) but it was linearly correlated with SI (r = 0.26; p = 0.046) and had a tendency to have a negative correlation with BNP level (r = −0.26; p = 0.07). These results suggest that LV myocardial trabeculation thickness increases linearly with the LV shape sphericity and has a tendency to decrease with the rise of LV pressure regime assessed by BNP level.

Ventricular Chamber Sphericity During Spaceflight and Parabolic Flight Intervals of Less Than 1 G

Pathology driven alterations in the geometric shape of the heart have been found to result in regional changes in ventricular wall stress and a remodeling of the myocardium. If reductions in the gravitational forces acting on the heart produce similar changes in the overall contour of the ventricles, this modification might also induce adaptations in the cardiac structure during long-term spaceflight. In this study we examined the changes in left ventricle (LV) shape in spaceflight and during parabolic flights. The diastole dimensions of the human LV were assessed with echocardiography during spaceflight and in parabolic flights which replicated the gravity of the Moon, Mars, and spaceflight and were compared to findings in Earth's gravity. LV dimensions were translated into circularity indices and geometric aspect ratios and correlated with their corresponding gravitational conditions. During parabolic flight, a linear relationship (r = 0.99) was found between both the circularity index and geometric aspect ratio values and the respective gravitational fields in which they were measured. During spaceflight (N = 4) and parabolic flights (N = 3), there was an average 4.1 and 4.4% higher circularity index and a 5.3 and 8.1% lower geometric aspect ratio, respectively. A correlative trend was found between the degree of LV sphericity and the amount of gravitational force directed caudal to the longitudinal orientation of the body. The importance of this finding is uncertain, but may have implications regarding physiologic adaptations in the myocardial structure secondary to changes in LV wall stress upon prolonged exposure to microgravity.

Role of matricellular proteins in cardiac tissue remodeling after myocardial infarction

After onset of myocardial infarction (MI), the left ventricle (LV) undergoes a continuum of molecular, cellular, and extracellular responses that result in LV wall thinning, dilatation, and dysfunction. These dynamic changes in LV shape, size, and function are termed cardiac remodeling. If the cardiac healing after MI does not proceed properly, it could lead to cardiac rupture or maladaptive cardiac remodeling, such as further LV dilatation and dysfunction, and ultimately death. Although the precise molecular mechanisms in this cardiac healing process have not been fully elucidated, this process is strictly coordinated by the interaction of cells with their surrounding extracellular matrix (ECM) proteins. The components of ECM include basic structural proteins such as collagen, elastin and specialized proteins such as fibronectin, proteoglycans and matricellular proteins. Matricellular proteins are a class of non-structural and secreted proteins that probably exert regulatory functions through direct binding to cell surface receptors, other matrix proteins, and soluble extracellular factors such as growth factors and cytokines. This small group of proteins, which includes osteopontin, thrombospondin-1/2, tenascin, periostin, and secreted protein, acidic and rich in cysteine, shows a low level of expression in normal adult tissue, but is markedly upregulated during wound healing and tissue remodeling, including MI. In this review, we focus on the regulatory functions of matricellular proteins during cardiac tissue healing and remodeling after MI.

Left ventricular regional wall curvedness and wall stress in patients with ischemic dilated cardiomyopathy

Geometric remodeling of the left ventricle (LV) after myocardial infarction is associated with changes in myocardial wall stress. The objective of this study was to determine the regional curvatures and wall stress based on three-dimensional (3-D) reconstructions of the LV using MRI. Ten patients with ischemic dilated cardiomyopathy (IDCM) and 10 normal subjects underwent MRI scan. The IDCM patients also underwent delayed gadolinium-enhancement imaging to delineate the extent of myocardial infarct. Regional curvedness, local radii of curvature, and wall thickness were calculated. The percent curvedness change between end diastole and end systole was also calculated. In normal heart, a short- and long-axis two-dimensional analysis showed a 41 +/- 11% and 45 +/- 12% increase of the mean of peak systolic wall stress between basal and apical sections, respectively. However, 3-D analysis showed no significant difference in peak systolic wall stress from basal and apical sections (P = 0.298, ANOVA). LV shape differed between IDCM patients and normal subjects in several ways: LV shape was more spherical (sphericity index = 0.62 +/- 0.08 vs. 0.52 +/- 0.06, P < 0.05), curvedness at end diastole (mean for 16 segments = 0.034 +/- 0.0056 vs. 0.040 +/- 0.0071 mm(-1), P < 0.001) and end systole (mean for 16 segments = 0.037 +/- 0.0068 vs. 0.067 +/- 0.020 mm(-1), P < 0.001) was affected by infarction, and peak systolic wall stress was significantly increased at each segment in IDCM patients. The 3-D quantification of regional wall stress by cardiac MRI provides more precise evaluation of cardiac mechanics. Identification of regional curvedness and wall stresses helps delineate the mechanisms of LV remodeling in IDCM and may help guide therapeutic LV restoration.

Impact of Surgical Ventricular Restoration on Diastolic Function: Implications of Shape and Residual Ventricular Size

Limited data are available on left ventricle (LV) diastolic function in patients with ischemic dilated cardiomyopathy submitted to surgical ventricular restoration (SVR). The purpose of this study was to assess postoperative diastolic function changes and identify potential predictors of its worsening. One hundred and forty-six patients (65 +/- 9 years) with previous anterior myocardial infarction were evaluated before and after SVR. Hemodynamic and geometric parameters including the sphericity index and conicity index were measured. Diastolic function was explored using the transmitral flow velocity pattern, and four classes were defined: normal, abnormal relaxation, pseudonormal, and restrictive pattern. Diastolic function was defined as unchanged (no difference in diastolic pattern), improved (at least one class less), or worsened (at least one class more or, in the case of preoperative restrictive pattern, an early transmitral flow velocity to atrial flow velocity [E/A] ratio increase of at least 20%). The filling pattern before SVR was normal in 7 patients (4.8%), abnormal relaxation in 99 (68%), pseudonormal in 28 (19%), and restrictive in 12 (8.2%). After SVR, the filling pattern was unchanged in 105 patients (72%), improved in 14 (9.6%), and worsened in 27 (18.4%). Based on the univariate analysis, the preoperative conicity index and the end-diastolic volume difference (the result of surgical volume reduction) were associated with a diastolic pattern worsening. Diastolic function did not change or improve in the majority of patients. In the minority of patients who experienced worsening, this was associated with the preoperative LV shape and residual volume.

Mechanisms and Clinical Implications of Asymptomatic Mitral Regurgitation in Patients With Left Ventricular Dysfunction

Functional mitral regurgitation (MR) is common in patients with chronic heart failure (CHF). During exercise, hemodynamic changes such as elevation of blood pressure and an increase in the left ventricular end-diastolic dimension may increase MR. Severity of CHF is reflected by exercise tolerance and, therefore, MR during exercise is supposed to indicate the severity of heart failure. The degree of MR increase and left ventricle (LV) shape was quantified during exercise in CHF patients and were compared with exercise tolerance. Twenty patients with CHF (mean age: 63 years) underwent dynamic cycle exercise at steady-state levels of 80% and 150% of the anaerobic threshold (AT). The MR jet area and left atrial (LA) area were measured during exercise and the ratio of MR/LA was calculated. The LV shape was assessed by calculating the ratio of the major to the minor axis. The MR/LA ratio increased during exercise (rest: 16.9+/-6.5%, 80% AT: 21.9+/-8.9%, 150% AT: 30.9+/-11.2%; p<0.01) and the LV shape became more spherical (rest: 1.34+/-0.10, 80% AT: 1.31+/-0.10, 150% AT: 1.23+/-0.11; p<0.05). There was a negative correlation between MR/LA ratio and the ratio of the major to the minor axis (-0.722, r<0.01). MR during exercise increases as the severity of CHF increases. Functional MR is correlated with the shape of the LV.

Incomplete Ventricular Septal Rupture Following Blunt Chest Trauma

This report describes a case of traumatic incomplete rupture of the ventricular septum, a rare complication caused by blunt chest trauma. Although a serial ECG progressed its course similar to acute anteroseptal myocardial infarction in this case, there was little clinical clue of septal tear. The diagnosis was established by transthoracic echocardiography. The authors chose a conservative line of management rather than surgical repair for incomplete septal rupture because of the patent's stable clinical course and hemodynamic status. A sequence of echocardiography during a 32-day stay in the hospital showed no change in the extent of incomplete septal rupture, septal structure, systolic function, and shape of left ventricle and also obtained no evidence of shunting through the rupture. In conclusion, echocardiography is a useful investigation to make a diagnosis as well as for follow-up in case of incomplete ventricular septal rupture. A close follow-up of incomplete septal rupture with serial echocardiography should be performed, because several cases of delayed ventricular septal rupture following blunt chest trauma have been reported.

Novel left ventriculoplasty for nonischemic dilated cardiomyopathy with functional mitral regurgitation

Novel left ventriculoplasty for nonischemic dilated cardiomyopathy with functional mitral regurgitation

New Leftventricle Functional Estimation by Leftventricle Shape Analysis with Ultrasoundcardiography

New Leftventricle Functional Estimation by Leftventricle Shape Analysis with Ultrasoundcardiography

Initial Safety and Feasibility Clinical Trial of the Myosplint Device

The Myocor Myosplint device is a passive implantable device for the treatment of heart failure by changing the geometry of the left ventricle (LV). The purpose of this evaluation was to describe the first human experience with the Myosplint device to demonstrate safety and feasibility. Of the first consecutive 21 patients, 9 patients received a Myosplint device alone while 12 patients underwent a mitral valve repair as well. Safety and efficacy data were gathered at enrollment and during follow-up. No serious device-related adverse events or device failures were observed. Three patients died during the follow-up period, and 2 patients underwent heart transplantation. There was a significant improvement in the New York Heart Association (NYHA) functional class from 3.0 +/- 0.3 at baseline to 2.1 +/- 0.7 at 6 months (p = 0.001). Both LV end-diastolic and end-systolic volumes had decreased at follow-up. The LV ejection fraction significantly increased in the Myosplint alone group (from 17.1 +/- 4.0% at baseline to 21.8 +/- 4.1% at 3 months and 23.1 +/- 7.2% at 6 months) but not in the Myosplint and mitral valve repair group. The mitral regurgitation (MR) grade had a significant (p = 0.002) linear relationship with the NYHA functional class. The initial clinical experience of the Myosplint device demonstrated both safety and feasibility, validating the LV shape change concept in humans. A remodeling solution must, however, include MR resolution, to illustrate the need for a device that can simultaneously reduce or eliminate functional MR off-pump.

A Surgical Approach to Severe Congestive Heart Failure-Overlapping Ventriculoplasty

Previously we developed a new procedure of overlapping cardiac volume reduction (OLCVR) surgery for patients with dilated cardiomyopathy refractory to medical treatment. Papillary muscle plication (PMP) when combined with OLCVR may achieve a better clinical outcome. To investigate the early and intermediate results of OLCVR with or without PMP. Twenty-five patients (21 males, 4 females, aged 60 +/- 13 years) with either ischemic (n = 7) or nonischemic (n = 18) dilated cardiomyopathy underwent either isolated OLCVR (n = 11; Original Group) or PMP combined with OLCVR (n = 14; Integrated Group). Early deaths occurred in two (8%) from a noncardiac cause and late deaths in six, two from a cardiac and four from a noncardiac cause. Postoperative data in survivors were significantly improved in terms of NYHA functional class (from 3.6 +/- 1.9 to 1.6 +/- 1.1), ejection fraction (from 18 +/- 6% to 31 +/- 8%), left ventricular diastolic dimension (from 73 +/- 9 to 65 +/- 6 mm), and left ventricular end-diastolic volume index (from 194 +/- 81 to 128 +/- 43 mL/m2) (p < 0.05) in selected comparative cases. One-year crude and cause-specific survivals were 70.9% and 83.1%, respectively, at a mean follow-up of 12.8 months. One-year crude survival of the Integrated and Original Group was 85.7% and 55.6%, respectively (p = 0.24). Although limitations exist in evaluating operative results, we consider OLCVR to be a relatively safe and effective procedure for selected patients with dilated cardiomyopathy. The addition of PMP to OLCVR may enhance the elliptic formation of left ventricle shape and improve mitral valve tethering, but further study is mandatory.

LV Shape and Motion: B-Spline-Based Deformable Model and Sequential Motion Decomposition

In this paper, we extend a previous work by J. Park and propose a uniform framework to reconstruct left ventricle (LV) geometry/motion from tagged MR images. In our work, the LV is modeled as a generalized prolate spheroid, and its motion is decomposed into four components-global translation, polar radial/z-axis compression, twisting, and bending. By formulating model parameters as tensor products of B-splines, we develop efficient algorithms to quickly reconstruct LV geometry/motion from extracted boundary contours and tracked planar tags. Experiments on both synthesized and in vivo data are also reported.

Does Pre-MI Angina Protect Against Post-MI LV Remodeling?

Changes in left-ventricle size and shape (LV remodeling) are associated with increased mortality risk after MI. To assess the potential link between

Shape of the left ventricle and its computer modelling

A simple computer program was made to draw different left ventricle shapes in order to support the theory of elongation and to get a visual presentation of the shape of the left ventricle. Experimental data, obtained from echocardiography and Simpson's rule, were used for this program. The results yielded different shapes under different physiological circumstances, indicating the sensitivity of the method. It was concluded that these figures (shapes) support the use of elongation as a shape index.

Anisotropic filtering for model-based segmentation of 4D cylindrical echocardiographic images

This paper presents a 4D (3D+time) echocardiographic image anisotropic filtering and a 3D model-based segmentation system. To improve the extraction of left ventricle boundaries, we rely on two preprocessing stages. First, we apply an anisotropic filter that reduces image noise. This 4D filter takes into account the spatial and temporal nature of echocardiographic images. Second, we adapt the usual gradient filter estimation to the cylindrical geometry of the 3D ultrasound images. The reconstruction of the endocardium takes place by deforming a deformable simplex mesh having an a priori knowledge of left ventricle shape and that is guided by a region-based data attraction force. The external force formulation improves the segmentation robustness against noise and outliers. We illustrate our method by showing experimental results on very challenging sparse and noisy ultrasound images of the heart and by computing quantitative measurements of the left ventricle volume.

Myosplint implant and shape-change procedure: intra- and peri-operative safety and feasibility

Background In patients with dilated cardiomyopathy (DCM), the heart enlarges, leading to a corresponding increase in ventricular wall stress. To reduce the stress, transventricular tension members (Myosplint, Myocor, Inc.) were implanted to change the left ventricle (LV) effective radius and to reduce the LV wall stress by 20%. We conducted this study to evaluate the intra- and peri-operative safety and feasibility of LV–shape change therapy. Methods In 7 patients, all diagnosed with DCM, Myosplints were implanted. New York Heart Association class ranged from III–IV, and LV end-diastolic diameter ranged from 70 to 102 mm. Mitral valve regurgitation was classified as mild in 3 and moderate in 4 cases. Four patients underwent mitral valve annuloplasty. Results We observed no significant device-related complications, such as thromboembolism, bleeding, device instability, or vascular damage, at 90 days. Early indications in a small patient population demonstrate some improvements in clinical parameters. Conclusions From this initial experience, one may conclude that placement of the Myosplint devices can be safely performed without early, significant adverse events. In patients with significant mitral valve incompetence, concomitant mitral valve repair is indicated to realize the full benefit of the procedure. This study also suggests that Myosplints can be safely implanted in combination with mitral valve repair. The long-term effect of each procedure on cardiac function and survival will require further evaluation.