Mitral Annular Kinetics, Left Atrial, and Left Ventricular Diastolic Function Post Mitral Valve Repair in Degenerative Mitral Regurgitation.
ABSTRACT: OBJECTIVE:The relationship of mitral annular (MA) kinetics to left ventricular (LV) and left atrial (LA) function before and after mitral valve (MV) repair has not been well studied. Here we sought to provide comprehensive analysis that relates to MA motions, and LA and LV diastolic function post MV repair. METHODS:Three-dimensional analyses of mitral annular motion, LA function, and LV volumetric and diastolic strain rates were performed on 35 degenerative mitral regurgitation (MR) patients at baseline and 1-year post MV repair, and 51 normal controls, utilizing cardiac magnetic resonance imaging with tissue tagging. RESULTS:All had normal LV ejection fraction (EF) at baseline. LV and LA EFs decreased 1-year post-surgery vs. controls. LV early diastolic myocardial strain rates decreased post-surgery along with decreases in normalized early diastolic filling rate, E/A ratio, and early diastolic MA relaxation rates. Post-surgical LA late active kick remained higher in MR patients vs. control. LV and LA EFs were significantly associated with peak MA centroid to apex shortening. Furthermore, during LV systolic phase, peak LV ejection and LA filling rates were significantly correlated with peak MA centroid to apex shortening rate, respectively. While during LV diastolic phase, both peak early diastolic MA centroid to apex relaxation rate and LA ejection rate were positively significantly associated with LV peak early diastolic filling rate. CONCLUSION:MA motion is significantly associated with LA and LV function. Mitral annular motion, left atrial function, and LV diastolic strain rates are still impaired 1?year post MV repair. Long-term effects of these impairments should be prospectively evaluated.
Project description:The extent of mitral annular (MA) remodeling and dysfunction is correlated with the severity of mitral regurgitation (MR) as well as left atrial (LA) and left ventricular (LV) dilation. MA dysfunction may be a useful prognostic factor for operative timing and MR recurrence after successful mitral valve (MV) repair. The aim of this study was to evaluate additive prognostic factors of MA non-planarity using real-time 3D transesophageal echocardiography (RT3D-TEE) analysis in patients with chronic severe MR and preserved LV systolic function.Forty-seven patients with chronic severe MR and preserved LV systolic function scheduled for MV repair were prospectively enrolled. Echocardiographic studies were performed before surgery and postoperatively within 2 weeks and at least 6 months after surgery. RT3D-TEE was performed before the operation and immediately post-operative.Mean age was 55.4 ± 15.1 years and 24 were male. Annulus height/body surface area (BSA) obtained via RT3D-TEE was correlated with the degree of postoperative LA remodeling. Patients were divided into two groups by average baseline annulus height/BSA. Patients with normal annular height had a smaller postoperative LV end-diastolic dimension, LV end-systolic dimension and LA volume index than patients with decreased annular height. Preoperative annulus height/BSA values strongly predicted postoperative LA remodeling.MA height may be a useful prognostic factor for determining the timing of surgery in patients with chronic primary MR. Annulus height/BSA assessed via RT3D-TEE may provide additional information predictive of postoperative LA remodeling after successful MV repair.
Project description:BACKGROUND: Mitral annular disjunction (MAD) consists of an altered spatial relation between the left atrial wall, the attachment of the mitral leaflets, and the top of the left ventricular (LV) free wall, manifested as a wide separation between the atrial wall-mitral valve junction and the top of the LV free wall. Originally described in association with myxomatous mitral valve disease, this abnormality was recently revisited by a surgical group that pointed its relevance for mitral valve reparability. The aims of this study were to investigate the echocardiographic prevalence of mitral annular disjunction in patients with myxomatous mitral valve disease, and to characterize the clinical profile and echocardiographic features of these patients. METHODS: We evaluated 38 patients with myxomatous mitral valve disease (mean age 57 ± 15 years; 18 females) and used standard transthoracic echocardiography for measuring the MAD. Mitral annular function, assessed by end-diastolic and end-systolic annular diameters, was compared between patients with and without MAD. We compared the incidence of arrhythmias in a subset of 21 patients studied with 24-hour Holter monitoring. RESULTS: MAD was present in 21 (55%) patients (mean length: 7.4 ± 8.7 mm), and was more common in women (61% vs 38% in men; p = 0.047). MAD patients more frequently presented chest pain (43% vs 12% in the absence of MAD; p = 0.07). Mitral annular function was significantly impaired in patients with MAD in whom the mitral annular diameter was paradoxically larger in systole than in diastole: the diastolic-to-systolic mitral annular diameter difference was -4,6 ± 4,7 mm in these patients vs 3,4 ± 1,1 mm in those without MAD (p < 0.001). The severity of MAD significantly correlated with the occurrence of non-sustained ventricular tachycardia (NSVT) on Holter monitoring: MAD›8.5 mm was a strong predictor for (NSVT), (area under ROC curve = 0.74 (95% CI, 0.5-0.9); sensitivity 67%, specificity 83%). There were no differences between groups regarding functional class, severity of mitral regurgitation, LV volumes, and LV systolic function. CONCLUSIONS: MAD is a common finding in myxomatous mitral valve disease patients, easily recognizable by transthoracic echocardiography. It is more prevalent in women and often associated with chest pain. MAD significantly disturbs mitral annular function and when severe predicts the occurrence of NSVT.
Project description:A miniature pig model of ischemic mitral regurgitation (IMR) was developed by posterior mitral chordae tendinae rupture and implantation of an ameroid constrictor. A 2.5-mm ameroid constrictor was placed around the left circumflex coronary artery (LCX) of male Tibetan miniature pigs to induce ischemia, while the posterior mitral chordae tendinae was also ruptured. X-ray coronary angiography, ECG analysis, echocardiography, and magnetic resonance imaging (MRI) were used to evaluate heart structure and function in pigs at baseline and one, two, four and eight weeks after the operation. Blood velocity of the mitral regurgitation was found to be between medium and high levels. Angiographic analyses revealed that the LCX closure was 10-20% at one week, 30-40% at two weeks and 90-100% at four weeks subsequent ameroid constrictor implantation. ECG analysis highlighted an increase in the diameter of the left atria (LA) at two weeks post-operation as well as ischemic changes in the left ventricle (LV) and LA wall at four weeks post-operation. Echocardiography and MRI further detected a gradual increase in LA and LV volumes from two weeks post-operation. LV end diastolic and systolic volumes as well as LA end diastolic and systolic volume were also significantly higher in pig hearts post-operation when compared to baseline. Pathological changes were observed in the heart, which included scar tissue in the ischemic central area of the LV. Transmission electron microscopy highlighted the presence of contraction bands and edema surrounding the ischemia area, including inflammatory cell infiltration within the ischemic area. We have developed a pig model of IMR using the posterior mitral chordae tendineae rupture technique and implantation of an ameroid constrictor. The pathological features of this pig IMR model were found to mimic the natural history and progression of IMR in patients.
Project description:remodeling of the mitral annulus contributes to progression of mitral regurgitation (MR). In patients with moderate-to-severe MR, short-term treatment with ?-blockers has been shown to increase left ventricular (LV) end-diastolic and end-systolic volume, and this could deleteriously increase mitral valve annular dimensions. The objective of this study was to quantify the effects of a short duration of ?-blocker treatment on mitral annular dimensions and dynamics in patients with MR due to primary degenerative valve disease.twenty-five patients with moderate-to-severe degenerative MR and normal LV systolic function were studied in a double-blind crossover experiment using a ?1-selective adrenergic blocker and placebo administered for 14±3 days. Cardiac MRI images were acquired after each treatment period to quantify mitral annular dimensions. At end diastole, there was no change in annular area (1659±331 versus 1632±299 mm(2); P<0.19), annular perimeter (154.3±16.4 versus 152±13.9 mm; P<0.13), septal-lateral (SL) dimension (38.0±5 versus 39.0±4.5 mm; P<0.15), or annular height (9.8±3.8 versus 9.5±2.5 mm; P<0.53). ?-blockade resulted in significant end-diastole decreases in commissure-commissure dimension (48.9±4.6 versus 47.2±4.0 mm; P<0.01) and eccentricity (1.3±0.2 versus 1.2±0.1; P<0.01). At end systole (ES), ?-blockade conferred a small, but significant decrease in annular perimeter (161.0±19.3 versus 156.8±16.9 mm; P<0.04) and eccentricity (1.2±0.1 versus 1.1±0.1; P<0.02), and the SL dimension significantly increased (41.5±5.7 versus 43.0±5.3 mm; P<0.03). Commissure-commissure dimension, annular area, and annular height at ES were not significantly different.despite significant increases in LV end-diastolic and end-systolic volume, short-term ?-blocker treatment of patients with moderate-to-severe MR reduced or preserved all mitral annular dimensions except SL at ES.
Project description:Highly resolved three-dimensional (3D) fluid structure interaction (FSI) simulation using patient-specific echocardiographic data can be a powerful tool for accurately and thoroughly elucidating the biomechanics of mitral valve (MV) function and left ventricular (LV) fluid dynamics. We developed and validated a strongly coupled FSI algorithm to fully characterize the LV flow field during diastolic MV opening under physiologic conditions. Our model revealed that distinct MV deformation and LV flow patterns developed during different diastolic stages. A vortex ring that strongly depended on MV deformation formed during early diastole. At peak E wave, the MV fully opened, with a local Reynolds number of ~5500, indicating that the flow was in the laminar-turbulent transitional regime. Our results showed that during diastasis, the vortex structures caused the MV leaflets to converge, thus increasing mitral jet's velocity. The vortex ring became asymmetrical, with the vortex structures on the anterior side being larger than on the posterior side. During the late diastolic stages, the flow structures advected toward the LV outflow tract, enhancing fluid transport to the aorta. This 3D-FSI study demonstrated the importance of leaflet dynamics, their effect on the vortex ring, and their influence on MV function and fluid transport within the LV during diastole.
Project description:Recent findings suggest that left atrial (LA) function is more strongly related to adverse prognosis than LA volumes. We aimed to evaluate the associations between LA volumes and Doppler filling indices with LA function. Echocardiographic LA volumes (LAVs), mitral valve early (MV-E) and late (MV-A) peak flow velocities, and mitral atrioventricular plane tissue-Doppler early (TD-e') and late (TD-a') peak velocities were obtained in 320 patients with acute myocardial infarction (AMI) free from atrial fibrillation and more than moderate valvular disease. LA function was estimated as the LA emptying fraction (LAEF), that is 100× (LAVmax-LAVmin)/LAVmax. LA reservoir volume was calculated as LAVmax-LAVmin and LA transit volume as LV stroke volume-reservoir volume. In restricted cubic spline regression analyses with multivariable adjustment, a reduced LAEF was strongly associated with smaller reservoir volume, larger transit volume, LAVmax, LAVpreA and especially LAVmin. MV-E linearly increased with a lower LAEF, whereas MV-A decreased but only below LAEF levels of approximately 45%. The resulting E/A ratio showed a sudden increase in LAEF levels below ~45%. Lower TD-a' was linearly associated with a lower LAEF. In conclusion, a reduced atrial function was associated with smaller LA reservoir volume, larger LA transit volume, lower TD-a', a non-linear decrease in MV-A and a non-linear increase in E/A. Our findings are likely a reflection of the adaptation to sustain LV filling volume and counteracting a rise in pulmonary venous pressure in face of an enhanced LV end-diastolic pressure.
Project description:PURPOSE:To present and validate a method for automated extraction and analysis of the temporal evolution of the mitral valve (MV) vortex ring from MR 4D-flow data. METHODS:The proposed algorithm uses the divergence-free part of the velocity vector field for Q criterion-based identification and tracking of MV vortex ring core and region within the left ventricle (LV). The 4D-flow data of 20 subjects (10 healthy controls, 10 patients with ischemic heart disease) were used to validate the algorithm against visual analysis as well as to assess the method's sensitivity to manual LV segmentation. Quantitative MV vortex ring parameters were analyzed with respect to both their differences between healthy subjects and patients and their correlation with transmitral peak velocities. RESULTS:The algorithm successfully extracted MV vortex rings throughout the entire cardiac cycle, which agreed substantially with visual analysis (Cohen's kappa = 0.77). Furthermore, vortex cores and regions were robustly detected even if a static end-diastolic LV segmentation mask was applied to all frames (Dice coefficients 0.82 ± 0.08 and 0.94 ± 0.02 for core and region, respectively). Early diastolic MV vortex ring vorticity, kinetic energy and circularity index differed significantly between healthy controls and patients. In contrast to vortex shape parameters, vorticity and kinetic energy correlated strongly with transmitral peak velocities. CONCLUSION:An automated method for temporal MV vortex ring extraction demonstrating robustness with respect to LV segmentation strategies is introduced. Quantitative vortex parameter analysis indicates importance of the MV vortex ring for LV diastolic (dys)function.
Project description:BACKGROUND:In ischemic mitral regurgitation (IMR), ring annuloplasty is associated with a significant rate of recurrent MR. Ring size is based on intertrigonal distance without consideration of left ventricular (LV) size. However, LV size is an important determinant of mitral valve (MV) leaflet tethering before and after repair. We aimed to determine whether LV-MV ring mismatch (mismatch of LV size relative to ring size) is associated with recurrent MR in patients with IMR after restrictive ring annuloplasty. METHODS:Patients with moderate or severe IMR from the 2 Cardiothoracic Surgical Trials Network IMR trials who received MV repair were examined at 1 year after surgery. Baseline LV size was assessed by LV end-diastolic dimension and LV end-systolic dimension (LVESd). LV-MV ring mismatch was calculated as the ratio of LV to ring size (LV end-diastolic dimension/ring size and LVESd/ring size). RESULTS:At 1 year after ring annuloplasty, 45 of 214 patients with MV repair (21%) had moderate or greater MR. In univariable logistic regression analysis, larger LVESd (P=0.02) and LVESd/ring size (P=0.007) were associated with recurrent MR. In multivariable models adjusted for age, sex, baseline LV ejection fraction, and severe IMR, only LVESd/ring size (odd ratio per 0.5 increase, 2.20; 95% confidence interval, 1.05-4.62; P=0.038) remained significantly associated with 1-year MR recurrence. CONCLUSIONS:LV-MV ring size mismatch is associated with increased risk of MR recurrence. This finding may be helpful in guiding choice of ring size to prevent recurrent MR in patients undergoing MV repair and in identifying patients who may benefit from MV repair with additional subvalvular intervention or MV replacement rather than repair alone. CLINICAL TRIAL REGISTRATION:URL:http://clinicaltrials.gov. Unique identifiers: NCT00806988 and NCT00807040.
Project description:This study sought to assess patterns and functional consequences of mitral apparatus infarction after acute myocardial infarction (AMI).The mitral apparatus contains 2 myocardial components: papillary muscles and the adjacent left ventricular (LV) wall. Delayed-enhancement cardiac magnetic resonance (DE-CMR) enables in vivo study of inter-relationships and potential contributions of LV wall and papillary muscle infarction (PMI) to mitral regurgitation (MR).Multimodality imaging was performed: CMR was used to assess mitral geometry and infarct pattern, including 3D DE-CMR for PMI. Echocardiography was used to measure MR. Imaging occurred 27 ± 8 days after AMI (CMR, echocardiography within 1 day).A total of 153 patients with first AMI were studied; PMI was present in 30% (n = 46 [72% posteromedial, 39% anterolateral]). When stratified by angiographic culprit vessel, PMI occurred in 65% of patients with left circumflex, 48% with right coronary, and only 14% of patients with left anterior descending infarctions (p <0.001). Patients with PMI had more advanced remodeling as measured by LV size and mitral annular diameter (p <0.05). Increased extent of PMI was accompanied by a stepwise increase in mean infarct transmurality within regional LV segments underlying each papillary muscle (p <0.001). Prevalence of lateral wall infarction was 3-fold higher among patients with PMI compared to patients without PMI (65% vs. 22%, p <0.001). Infarct distribution also impacted MR, with greater MR among patients with lateral wall infarction (p = 0.002). Conversely, MR severity did not differ on the basis of presence (p = 0.19) or extent (p = 0.12) of PMI, or by angiographic culprit vessel. In multivariable analysis, lateral wall infarct size (odds ratio 1.20/% LV myocardium [95% confidence interval: 1.05 to 1.39], p = 0.01) was independently associated with substantial (moderate or greater) MR even after controlling for mitral annular (odds ratio 1.22/mm [1.04 to 1.43], p = 0.01), and LV end-diastolic diameter (odds ratio 1.11/mm [0.99 to 1.23], p = 0.056).Papillary muscle infarction is common after AMI, affecting nearly one-third of patients. Extent of PMI parallels adjacent LV wall injury, with lateral infarction-rather than PMI-associated with increased severity of post-AMI MR.
Project description:OBJECTIVES:This study hypothesized that compensatory mitral leaflet area (MLA) adaptation occurs in patients with persistent atrial fibrillation (AF) without left ventricular (LV) dysfunction but has limitations that augment mitral regurgitation (MR). The study also explored whether asymmetrical annular dilation is matched by relative leaflet enlargement. BACKGROUND:Functional MR occurs in patients with AF and isolated annular dilation, but the relationship of MLA adaptation with annular area (AA) is unknown. METHODS:Three-dimensional echocardiographic images were acquired from 86 patients with quantified MR: 53 with nonvalvular persistent AF (23 MR+ with moderate or greater MR, 30 MR-) without LV dysfunction or dilation and 33 normal controls. Comprehensive 3-dimensional analysis included total diastolic MLA, adaptation ratios of MLA to annular area and MLA to leaflet closure area, and annular and tenting geometry. RESULTS:Total MLA was 22% larger in patients with AF than in controls, thus paralleling the increased AA. However, as AA increased, adaptive indices (MLA/AA ratio and ratio of MLA to closure area) plateaued, becoming lowest in MR+ patients (ratio of MLA to closure area = 1.63 ± 0.17 controls, 1.60 ± 0.11 MR-, 1.32 ± 0.10 MR+; p < 0.001). MR increased as the ratio of MLA to closure area decreased (R2 = 0.68; p < 0.001). The posterior-to-anterior MLA ratio remained constant, whereas the posterior-to-anterior mitral annulus perimeter increased (1.21 ± 0.16 controls, 1.32 ± 0.20 MR-, 1.46 ± 0.19 MR+; p < 0.001). Multivariate MR determinants were annular area, total MLA to closure area, and posterior-to-anterior perimeter ratios. CONCLUSIONS:MLA adaptively increases in AF with isolated annular dilation and normal LV function. This compensatory enlargement becomes insufficient with greater annular dilation, and the leaflets fail to match asymmetrical annular remodeling, thereby increasing MR. These findings can potentially help optimize therapeutic options and motivate basic studies of adaptive growth processes.