Isolated annular dilation does not usually cause important functional mitral regurgitation Comparison between patients with lone atrial fibrillation and those with idiopathic or ischemic cardiomyopathy

AbstractObjectivesWe sought to test whether isolated mitral annular (MA) dilation can cause important functional mitral regurgitation (MR).BackgroundMitral annular dilation has been considered a primary cause of functional MR. Patients with functional MR, however, usually have both MA dilation and left ventricular (LV) dilation and dysfunction. Lone atrial fibrillation (AF) can potentially cause isolated MA dilation, offering a unique opportunity to relate MA dilation to leaflet function.MethodsMid-systolic MA area, MR fraction, LV volumes and papillary muscle (PM) leaflet tethering length were compared by echocardiography among 18 control subjects, 25 patients with lone AF and 24 patients with idiopathic or ischemic cardiomyopathy (ICM).ResultsPatients with lone AF had a normal LV size and function, but MA dilation (isolated MA dilation) significant and comparable to that of patients with ICM (MA area: 8.0 ± 1.2 vs. 11.6 ± 2.3 vs. 12.5 ± 2.9 cm2[control vs. lone AF vs. ICM]; p < 0.001 for both lone AF and ICM). However, patients with lone AF had only modest MR, compared with that of patients with ICM (MR fraction: −3 ± 8% vs. 3 ± 9% vs. 36 ± 25%; p < 0.001 for patients with ICM). Multivariate analysis identified PM tethering length, not MA dilation, as an independent primary contributor to MR.ConclusionsIsolated annular dilation does not usually cause moderate or severe MR. Important functional MR also depends on LV dilation and dysfunction, leading to an altered force balance on the leaflets, which impairs coaptation

Assessing functional mitral regurgitation with exercise echocardiography: rationale and clinical applications

Secondary or functional mitral regurgitation (FMR) represents an increasing feature of mitral valve disease characterized by abnormal function of anatomically normal leaflets in the context of the impaired function of remodelled left ventricles. The anatomic and pathophysiological basis of FMR are briefly analyzed; in addition, the role of exercise echocardiography for the assessment of FMR is discussed in view of its relevance to clinical practice

Relationship between mitral leaflets angles, left ventricular geometry and mitral deformation indices in patients with ischemic mitral regurgitation: imaging by echocardiography and cardiac magnetic resonance

Chronic ischemic mitral regurgitation (IMR) is associated with a markedly worse prognosis after myocardial infarction (MI).The study aimed to evaluate the relationship between anterior and posterior mitral leaflet angle (MLA) values, left ventricle remodeling and severity of ischaemic mitral regurgitation (IMR). Methods: Forty-two patients (age 63.5 ± 9.7 years, 36 men) with chronic IMR (regurgitant volume, RV > 20 ml; >6 months after MI) underwent transthoracic echocardiography (TTE) and cardiovascular magnetic resonance (CMR) imaging. Anterior and posterior MLA, determined by echocardiography, were correlated with indices of LV remodeling, mitral apparatus deformation and IMR severity by CMR. The anterior and posterior MLA was 25.41 ± 4.28 and 38.37 ± 8.89° (mean ± SD). In 5 patients (11.9%) the posterior MLA was ≥45°. There was a significant correlation between anterior MLA and RV (r = 0.74, P = 0.01). For patients with RV > 30 ml this correlation was stronger (r = 0.97, P = 0.005) and, in addition, there was a correlation between the RV and posterior MLA (r = 0.90, P = 0.037), between tenting area and posterior MLA (r = 0.90, P = 0.04), and between tenting area and anterior MLA (r = 0.82, P = 0.08). With regard to LV remodeling parameters, there was weaker but significant correlation between posterior MLA and LV end-diastolic volume index (r = 0.35, P = 0.031), LV end-systolic volume index (r = 0.37, P = 0.021), stroke volume (r = 0.35, P = 0.03), sphericity index (r = 0.33, P = 0.041). Anterior MLA correlated with wall motion score index (r = 0.41, P = 0.019). Besides, there was a correlation between posterior MLA and left atrial volume (r = 0.41, P = 0.012). Measurement of anterior and posterior MLA may play an important role in evaluating patients with IMR

Biodegradable microparticles loaded with thrombin receptor agonist peptide for gastric ulcer treatment in rats

peer reviewedThe aim of the current paper was to elaborate an immobilization method of thrombin receptor agonist peptide (TRAP-6) in biodegradable biocompatible poly(d,l)-lactide-co-glycolide (PLGA) inicroparticles and to demonstrate the effect of the entrapped peptide for tissue repair, namely,for a gastric ulcer treatment in rats. TRAP-6 was entrapped in polymer using w/o/w double emulsion-evaporation technique. The morphology of empty and TRAP-6 loaded microparticles was evaluated by light and scanning electron microscopy (SEM). In vitro release kinetics profile of TRAP-6 from microparticles was studied by HPLC. To investigate gastric mucosal protection effect in vivo, TRAP-6-loaded microparticles were administered in a rat stomach after a previous mucosal injury (a gastric ulcer). Microparticles with entrapped TRAP-6 were found to reduce both an inflammation and proliferation phases of wound healing, and thus accelerated tissue repair in rats.Programme de travail Région Wallonne/Fédération de Russie 2001- 2002, Art. 3. , Projet de coopération n°3, en collaboration avec : Shemyakin Institute Bioorganic Chemistry, Moscow, Professor Vitali P. Zubov et du Dr. Elena Markvichev