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Concept: Mitral valve prolapse

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OBJECTIVESThe Trifecta valve (St. Jude Medical) was introduced into clinical practice as a tri-leaflet stented pericardial valve designed for supra-annular placement in the aortic position. The present study aims to evaluate the preliminary results with this new bioprosthesis.METHODSSeventy patients underwent aortic valve replacement (AVR) with the Trifecta valve between August 2010 and December 2011. Thirty-three patients were male and 37 were female (52.9%). Mean age was 74.65 ± 7.63 (range 47-90 years). Prevalent cause of AVR was aortic stenosis in 64 (91.43%) patients. The mean preoperative pressure gradient was 50 ± 17 (range 20-84 mmHg), and the mean aortic valve area was 0.77 ± 0.33. Five (7.14%) patients were operated on due to aortic valve endocarditis. One patient was operated on due to isolated, severe aortic insufficiency. All patients were in New York Heart Association functional class III or IV. Twenty-eight (40%) patients underwent concomitant procedures.RESULTSConcomitant procedures were coronary artery bypass grafting (n = 25), mitral valve replacement (n = 1), ablation of atrial fibrillation (n = 1) and septal myomectomy (n = 1). There were no intraoperative deaths. The 30-day in-hospital mortality was 2.85% (2 of 70). One late death occurred during the in-hospital stay due to a multiorgan failure on postoperative day 60. There were 2 (2.85%) perioperative strokes. Mean pressure gradient decreased significantly from a preoperative value of 50 ± 17 mmHg to an intraoperative gradient of 9 ± 4 mmHg (Table 3). The mean gradients were 14, 11, 11, 8 and 6 mmHg for the 19, 21, 23, 25 and 27 mm valve size, respectively. No prosthesis dislocation, endocarditis, valve thrombosis or relevant aortic regurgitation was observed at discharge.CONCLUSIONSThe initial experience with the Trifecta valve bioprosthesis shows excellent outcomes with favourable early haemodynamics. Further studies with longer follow-up are needed to confirm those preliminary results.

Concepts: Cardiology, Heart, Mitral valve prolapse, Aortic valve, Valvular heart disease, Aortic valve stenosis, Aortic valve replacement, Aortic insufficiency

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Prolapse of mitral valve leaflets is a frequent disorder and the most common cause of severe mitral regurgitation in western countries. However, little is known about the effects of altitude on mitral valve prolapse. We studied the prevalence and echocardiographic characteristics of mitral valve prolapse at moderately high altitude and sea level.

Concepts: Mitral valve, Mitral regurgitation, Mitral valve prolapse, Regurgitation, Western world, Western culture, Valvular heart disease, Mitral valve replacement

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Percutaneous transcatheter mitral valvuloplasty is the indicated treatment of choice for symptomatic native mitral valve stenosis, but there have been limited reports of successful procedures of balloon valvuloplasty for bioprosthetic mitral valve stenosis. We present the case of a 62-year-old woman suffering from progressive dyspnea due to bioprosthetic mitral valve stenosis. The measured mean pressure gradient across the mitral valve was 30 mmHg and the mitral valve area was 0.73 cm(2). Redoing mitral replacement was considered high risk and was refused by the patient. Percutaneous balloon valvuloplasty was performed with an Inoue balloon catheter inflated to 20 mm. The patient’s symptoms immediately improved after the procedure, with no procedure-related complications. The mean pressure gradient across the valve decreased to 19 mmHg, and the mitral valve area increased to 1.21 cm(2) in postprocedural echocardiography. We conducted a literature search and identified 26 cases of balloon valvuloplasty for degenerated bioprosthetic valves. Of these, 14 cases were bioprosthetic mitral valves, and the results were favorable. However, more case reports are required to establish an evidence base for future expert recommendation of balloon valvuloplasty of prosthetic mitral valve. Meanwhile, balloon valvuloplasty will serve a niche role in highly selected patients with prosthetic mitral valve stenosis.

Concepts: Mitral valve, Mitral regurgitation, Mitral valve prolapse, Mitral stenosis, Mitral valve replacement, Mitral valve repair, Aortic valvuloplasty, Mitral valvuloplasty

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BACKGROUND: The prevalence of atrial fibrillation (AF) and the frequency cardioversion of AF postoperatively are different in different forms of mitral valve disease. We hypothesized that these differences would relate to different extent of histopathological characteristics and oxidative injury in different forms of mitral valve diseases. METHODS: Left atrial appendages were obtained from 24 patients of mitral valve disease with or without AF undergoing mitral valve surgery. Control data were obtained from left appendages of 4 persons in normal sinus rhythm (SR) died of traffic accident. Histopathology, immunohistochemistry, Western blotting and enzyme kinetics examination were performed to assess the extent of histopathological characteristics and oxidative injury. RESULTS: The average cross-sectional diameter of atrial myocyte of mitral stenosis (MS)+AF, MS+SR, mitral regurgitation (MR)+AF, MR+SR and control was 25.62±7.56 μm, 20.20±9.34 μm, 21.69±7.00 μm, 13.93±4.32 μm and 9.81±2.34 μm, respectively. Significantly statistical difference was found between each group (P<.05). Increased degree of atrial interstitial fibrosis was seen both in MS and MR with AF patients compared to other groups (P<.05), and the extent of fibrosis was more remarkable in MR patients compared to MS patients (P<.05). The extent of 3-nitrotyrosine (3-NT) immunoreactivity significantly increased in the patients with MS and AF compared to those of MR and AF (P<.05), and the immunoprevalence of 3-NT was significantly increased in patients of MS and SR compared to those of MR and SR (P<.05). Correlation analysis demonstrated a negative correlation between creatine kinase (CK) activity and extent of 3-NT immunoreactivity in atrial tissues (r=-0.382, P<.05). Significant decreases in CK activity were observed in myocardium from all patients of mitral valve disease with or without AF compared to controls (P<.05). Western blotting demonstrating an increased prevalence of 3-NT formation in CK-MM was detected compared to control group (P<.05). Correlation analysis demonstrated a negative correlation between CK-MM activity and extent of CK-MM tyrosine nitration (r=-0.446, P<.05). CONCLUSIONS: In different forms of mitral valve disease with different cardiac rhythm, the extent of histopathological characteristics and oxidative injury are different. Histopathological characteristics and oxidative injury not only relate to mitral valve disease but also relate to the development and sustain of AF.

Concepts: Heart, Atrial fibrillation, Mitral valve, Mitral regurgitation, Mitral valve prolapse, Regurgitation, Mitral stenosis, Left atrial appendage

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Alterations of normal mitral valve (MV) function lead to mitral insufficiency, i.e., mitral regurgitation (MR). Mitral repair is the most popular and most efficient surgical intervention for MR treatment. An annuloplasty ring is implanted following complex reconstructive MV repairs to prevent potential reoccurrence of MR. We have developed a novel finite element (FE)-based simulation protocol to perform patient-specific virtual ring annuloplasty following the standard clinical guideline procedure. A virtual MV was created using 3D echocardiographic data in a patient with mitral annular dilation. Proper type and size of the ring were determined in consideration of the MV apparatus geometry. The ring was positioned over the patient MV model and annuloplasty was simulated. Dynamic simulation of MV function across the complete cardiac cycle was performed. Virtual patient-specific annuloplasty simulation well demonstrated morphologic information of the MV apparatus before and after ring implantation. Dynamic simulation of MV function following ring annuloplasty demonstrated markedly reduced stress distribution across the MV leaflets and annulus as well as restored leaflet coaptation compared to pre-annuloplasty. This novel FE-based patient-specific MV repair simulation technique provides quantitative information of functional improvement following ring annuloplasty. Virtual MV repair strategy may effectively evaluate and predict interventional treatment for MV pathology.

Concepts: Cardiology, Heart, Simulation, Mitral valve, Mitral regurgitation, Mitral valve prolapse, Regurgitation, Mitral valve repair

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The aim of the study is to determine the impact of the underlying etiology (Barlow’s disease or fibroelastic deficiency) on left ventricular function in patients with degenerative mitral valve disease and severe mitral regurgitation.

Concepts: Heart, Mitral valve, Left ventricle, Mitral regurgitation, Mitral valve prolapse, Cardiac anatomy, Regurgitation, Diastole

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Background: In some inherited connective tissue diseases with involvement of the cardiovascular system, for example, Marfan syndrome, early impairment of left ventricular function, which have been described as Marfan-related cardiomyopathy has been reported. Our aim was to evaluate the left ventricular function in young adults with mitral valve prolapse without significant mitral regurgitation using two-dimensional strain imaging and to determine the possible role of the transforming growth factor-β pathway in its deterioration. Methods: We studied 78 young adults with mitral valve prolapse without mitral regurgitation in comparison with 80 sex-matched and age-matched healthy individuals. Longitudinal strain and strain rates were defined using spackle tracking. Concentrations of transforming growth factor-β1 and β2 in serum were determined by enzyme-linked immunosorbent assays. Results: In 29 patients, classic relapse was identified with a leaflet thickness of ≥ 5 mm; 49 patients had a non-classic mitral valve prolapse. Despite the similar global systolic function, a significant reduction in global strain was found in the classic group (-15.5 ± 2.9%) compared with the non-classic group (-18.7 ± 3.8; p = 0.0002) and the control group (-19.6 ± 3.4%; p < 0.0001). In young adults with non-classic prolapse, a reduction in longitudinal deformation was detected only in septal segments. Transforming growth factor-β1 and β2 serum levels were elevated in patients with classic prolapse as compared with the control group and the non-classic mitral valve prolapse group. Conclusions: These changes in the deformations may be the first signs of deterioration of the left ventricular function and the existence of primary cardiomyopathy in young adults with mitral valve prolapse, which may be caused by increased transforming growth factor-β signalling.

Concepts: Blood, Heart, Marfan syndrome, Mitral valve, Left ventricle, Mitral regurgitation, Mitral valve prolapse, Connective tissue

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Functional mitral regurgitation remains one of the most complex and controversial aspect-for both clinicians and surgeons-in the management of mitral valve disease in the context of left ventricular dysfunction. Given the current absence of clear guidelines, as well as of results from randomized trials comparing the outcome of different surgical strategies potentially available for this complex scenario, surgical decision making for these high-risk patients poses a real dilemma in the daily practice. The resulting surgical choices often represent a questionable combination of surgeons' personal feeling, local supplies, patients' life expectancy and risk/benefit ratios, opinions and statements of the experts, and so on. This review provides an overview of the present knowledge about the complex pathophysiology underlying functional mitral regurgitation, the different pathophysiology-guided surgical techniques suggested in the last decades, as well as the current results following these different surgical techniques.

Concepts: Hospital, Surgery, Mitral valve, Mitral regurgitation, Mitral valve prolapse, The Current, Valvular heart disease

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The objective of this study was to compare the auscultatory findings using traditional and electronic sensor-based stethoscopes. Thirty-three adult healthy Beagles (20 females, 13 males, mean age: 4.8 years, range 1.4-8 years) were auscultated by four investigators with different experiences (INVEST-1, -2, -3 and -4) independently with both stethoscopes. Final cardiological diagnoses were established by echocardiography. Mitral murmurs were heard with both stethoscopes by all investigators and echocardiography revealed mild mitral valve insufficiency in 7 dogs (21%, 4 females, 3 males). The statistical sensitivity (Se) in recognising cardiac murmurs proved to be 82% using the traditional stethoscope and 75% using the electronic one in the mean of the four examiners, whilst statistical specificity (Sp) was 99% by the traditional and 100% by the electronic stethoscope. The means of the auscultatory sensitivity differences between the two stethoscopes were 0.36 on the left and 0.59 on the right hemithorax, demonstrating an advantage for the electronic stethoscope being more obvious above the right hemithorax (P = 0.0340). The electronic stethoscope proved to be superior to the traditional one in excluding cardiac murmurs and especially in auscultation over the right hemithorax. Mitral valve disease was relatively common in this clinically healthy research Beagle population.

Concepts: Medicine, Mitral valve, Beagle, Mitral regurgitation, Mitral valve prolapse, Heart sounds, Auscultation, Stethoscope

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The aim of this study was to retrospectively assess the clinical usefulness of plasma atrial natriuretic peptide (ANP) concentrations for determining the severity of myxomatous mitral valve disease (MMVD) in dogs. Plasma ANP levels were found to be significantly higher in dogs with MMVD compared to healthy dogs, and plasma ANP levels increased significantly in dogs with progressive heart failure. In dogs with MMVD, stepwise regression analysis revealed that the left atrium/aorta ratio and fractional shortening could be used to predict the plasma ANP concentration. These results indicated that plasma ANP rose with an increase in the volume overload of the left side of the heart. Plasma ANP discriminated cardiomegaly from non-cardiomegaly caused by asymptomatic MMVD. We conclude, therefore, that plasma ANP concentrations may be a clinically useful tool for early diagnosis of asymptomatic MMVD in dogs.

Concepts: Regression analysis, Heart, Atrial fibrillation, Mitral valve, Mitral regurgitation, Mitral valve prolapse, Atrial natriuretic peptide, Stepwise regression