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PubMed2001

Hemodynamic evaluation of a new stentless autologous pericardial mitral valve.

BACKGROUND: There is no satisfactory mitral valve prosthesis. An ideal mitral valve substitute should be biologic, nonantigenic, and anatomically correct. METHODS: We developed a stentless, chordal-supported (including anterior basal stay chords) mitral valve made with glutaraldehyde-treated autologous pericardium. Eight such prostheses were implanted in sheep. RESULTS: Seven animals survived the operation and were studied postoperatively immediately, at 1 week, and at 1 month. Simultaneous left ventricular and left atrial pressures showed peak and mean transvalvular pressure gradients of 6+/-2 mm Hg and 1+/-1 mm Hg, respectively. Echocardiography performed intraoperatively and then 1 week and 1 month postoperatively showed normal valve leaflet movements. Color and pulsed Doppler echocardiography showed no sign of transvalvular stenosis or regurgitation. Effective orifice area was 5.39+/-0.35 cm2 at intraoperative, 5.51+/-0.29 cm2 1 week after operation (n = 5), and 5.51+/-.28 cm2 1 month after operation (n = 3). Three animals were sacrificed at 19 days and at 1 and 3 months. One animal is alive at 10 months. CONCLUSIONS: This new stentless pericardial mitral valve performed satisfactorily with low gradients and no regurgitation. Possible advantages of this pericardial valve are excellent hemodynamics, ease of construction and implantation, lack of immunogenicity, and low cost. Similarly designed valves but with a shorter nonglutaraldehyde treatment time have been used in 3 sheep monitored for more than 3 months.

Animals↗
PubMed1988

Marfan's syndrome: combined composite valve graft replacement of the aortic root and transaortic mitral valve replacement.

Echocardiographic studies in patients with Marfan's syndrome indicate that 95% eventually have aortic root dilatation, mitral valve prolapse, or a combination of these. Both lesions can progress and require operation for aortic root aneurysm, aortic valve insufficiency, and mitral valve insufficiency. This report reviews the simplified treatment of 6 patients by combined composite valve graft replacement of the aortic root and transaortic mitral valve replacement at one operation. All patients survived and are well for periods extending from 1 month to 12 months.

Adult↗
PubMed2007

The mitral hooks: visualization of mitral valve made easy.

Historically the mitral valve has been exposed through a variety of approaches from the standard left atriotomy to cardiac autotransplantation. Regardless of the approach, adequate exposure to the mitral valve is crucial to a successful valve repair or replacement. We describe a simple and effective way of bringing the mitral valve into view through a standard left atriotomy with the use of specially designed and modified mitral hooks. The mitral hooks provide excellent unobstructed view of the mitral valve, which is suitable for repair and replacement.

Humans↗
PubMed1991

[Do mitral valve components have the same predictive value in percutaneous balloon mitral valvuloplasty? Doppler echocardiography study].

PURPOSE: To evaluate the predictive value of mitral valve components in percutaneous balloon mitral valvuloplasty (PBMV). METHODS: 53 patients undergoing PBMV were submitted to an echocardiographic analysis of mitral valve in order to note mobility, thickness, calcification of leaflets and subvalvar apparatus (SV). Mitral valve area (VA) before and after PBMV was obtained using continuous wave Doppler. Patients were divided in group 1 (VA enhance inferior to 50%) and 2 (VA enhance equal or superior to 50%) and subgroups A (VA post PBMV inferior to 1.5 sqcm) and B (VA post PBMV equal or superior to 1.5 sqcm). Correlations between the score of each component of mitral valve and the results were established. RESULTS: Concerning to the total score, there was no significant difference between the groups and subgroups. Differences were significant when SV was analysed separately (p less than or equal to 0.001). VA average in patients with SV compromising grade 3 (1.28 +/- 0.26 sqcm) was inferior to those with grade 1 or 2 (p less than or equal to 0.001). CONCLUSION: SV has a higher predictive value in the success of PBMV.

Adolescent↗
PubMed1983

Frequency and extent of calcific deposits in purely regurgitant mitral valves: analysis of 108 operatively excised valves.

Operatively excised purely regurgitant mitral valves in 108 patients aged 21 to 73 years (mean 55) (63% men) undergoing isolated mitral valve replacement were examined for calcific deposits. Of the 108 patients, 19 (18%) had leaflet or chordal calcific deposits or both, but in each the deposits were small and did not appear to alter mitral function. Of the 19 patients with mitral calcium, 6 had had active infective endocarditis and the calcium likely represented healed vegetations; in 6 other patients, the leaflet calcium had extended from the mitral anulus in the setting of mitral valve prolapse. The average total serum cholesterol levels were higher in the patients with compared with those without mitral calcium. Thus, calcium deposits are relatively infrequent in adults with clinically isolated pure mitral regurgitation, and when they occur, the deposits are small and in themselves do not appear to contribute to mitral dysfunction.

Adult↗
PubMed2003

Immediate and early results of mitral valve repair at King Chulalongkorn Memorial Hospital.

OBJECTIVE: Comparison with prosthesis mitral valve replacement, mitral valve repair has lots of advantages. After valve repair, patients have better left ventricular function, a lower rate of thromboembolism and infective endocarditis. The authors studied early experience of mitral valve repair. MATERIAL AND METHOD: From January 2000 to May 2002, 43 consecutive patients with mitral regurgitation had mitral valve repair. Valve disease was degenerative in 51.2 per cent, ischemic in 18.7 per cent, rheumatic in 13.9 per cent, infectious in 11.6 per cent, and others in 4.6 per cent. Surgical techniques included P2 quadrangular resection (n = 13; 30.95%), chordal tranfer (n = 11; 26.19%), only annuloplasty (n = 10; 23.8%), artificial chordae (n = 3; 7.14%), commissural closure (n = 3; 7.14%), and others in 2 cases (4.76%). RESULT: Immediate post-operative echocardiogram showed no or trivial regurgitation in 95 per cent and moderate regurgitation in 5 per cent. There was no operative mortality, but 1 case had hospital mortality with 1-24 months follow-up, 90 per cent of cases had FC I and the other (10%) were in FC II. CONCLUSION: This preliminary experience provided promising immediate and early result. The authors believe that mitral valve repair is safe and seems to have a much better result than mitral valve replacement. However, a randomized control study and long-term follow-up, in the future, are important.

Adolescent↗
PubMed1976

Mitral valve prolapse in coronary artery disease.

Mitral valve motion, left ventricular segmental contraction and severity of arterial stenosis were analyzed in 92 patients with coronary artery disease and 28 patients with "atypical chest pain" and normal coronary arterio-rams. Mitral valve motion was evaluated for the presence or absence of leaflet prolapse. Segmental contraction was evaluated by calculating the percent shortening of six chords of the left ventricle measured from right anterior oblique ventriculograms. The severity of disease in each coronary vessel (left anterior descending, left circumflex and right coronary) was graded on a scale of 1 (0 to 30 percent stenosis) to 5 (complete occlusion). Mitral valve prolapse was not suspected clinically but observed angiographically in 15 of 92 patients with coronary artery disease and in 5 of 28 patients with normal coronary arteriograms. In nine patients with coronary artery disease, the prolapse was restricted to the posterior leaflet, in five it was in both the anterior and the posterior leaflets and in one patient in the anterior leaflet only. Mitral regurgitation was noted in seven patients with coronary artery disease; it was mild in six and moderate in one. Among the patients with coronary artery disease, 12 of the 15 (80 percent) with mitral valve prolapse had left ventricular asynergy compared with 63 of the 77 (82 percent) without valve prolapse. The mean scores for severity of disease in the left anterior descending, circumflex and right coronary arteries were, respectively, 4.2, 2.5 and 3.2 in the patients with valve prolapse and 4.2, 2.2 and 3.5 in those without prolapse. In summary, there was no significant correlation between mitral valve prolapse and distribution of coronary arterial obstructions or abnormal patterns of left ventricular segmental contraction. There was a high frequency of mitral valve prolapse in patients with severe coronary artery disease and in those with normal coronary arteriograms and atypical chest pain.

Adult↗
PubMed1989

[Combined aortic and mitral valve replacement with or without preservation of posterior mitral apparatus].

Seventy patients who underwent aortic and mitral valve replacement were reviewed. 37 patients had the mitral valve replaced with preservation of posterior mitral apparatus (AVR and modified MVR; modified group), and the others without (AVR and conventional MVR; conventional group). Hospital deaths occurred in 4 patients (12.1%) in conventional group and in only 1 patient (2.7%) in modified group. Four out of these five hospital deaths were due to low output syndrome (LOS). The other one died of unknown cause. Severe LOS, necessitating intra-aortic balloon pumping, occurred in 4 (12.1%) in conventional group and in 2 (5.4%) in modified group. In the early postoperative period modified group showed better left ventricular function than conventional group in terms of cardiac index and left ventricular stroke work index. Cardiac performance was evaluated by means of echocardiography at the time of discharge. Modified group showed better fractional shortening and shorter PEP/ET (pre-ejection period/ejection time). These findings suggest that the lower mortality of modified group is due to better left ventricular function preventing LOS in the early postoperative period, and that preserving the posterior mitral apparatus has a more beneficial effect on postoperative left ventricular function even in combined valve disease.

Aged↗
PubMed2004

Indications for mitral valve surgery.

The current indications for mitral valve surgery are summarized in this review. Remarkable advancements in surgical technique and in our ability to define the onset of ventricular dysfunction have led to increasingly liberal indications for mitral valve surgery. Mitral valve repair for mitral regurgitation (MR) might be employed in asymptomatic patients with normal left ventricular function if valve repair were almost certain while in patients with severe left ventricular dysfunction, where valve replacement with destruction of the valve apparatus is most unwise, successful repair can lead to an improved quality of life. However, much is left to be done: increased repair rate, better definition of the role of surgery in both ischemic and myopathic MR and the role of limited incision surgery are all on the exciting horizon of the future.

Female↗
PubMed1985

The effect of low-dose intravenous nitroglycerin on pulmonary hypertension immediately after replacement of a stenotic mitral valve.

The postoperative effect of infusion of nitroglycerin on pulmonary vasomotor dynamics was studied in 28 patients undergoing valve replacement for mitral valve stenosis. A 30% reduction in mean pulmonary arterial pressure (38.74 +/- 8.3 to 26.92 +/- 7.72 mm Hg, p less than .001) and a 48.4% reduction in pulmonary vascular resistance index (12.08 +/- 4.19 to 5.61 +/- 1.61 U/m2, p less than .001) were observed after nitroglycerin. While pulmonary driving pressure (mean pulmonary arterial pressure minus left atrial pressure) dropped by 50.8%, cardiac and stroke volume indexes increased by 25.5% and 24.2%, respectively. The ratio pulmonary/systemic vascular resistance decreased from 34.14% to 20.9% (p less than .001). There were no significant changes in mean systemic arterial pressure (86.89 +/- 13.5 to 83.5 +/- 9.3 mm Hg, p = NS) or heart rate (97.43 +/- 20.45 to 99.36 +/- 20.9 beats/min, p = NS); left and right atrial pressures decreased by 19.5% and 9.5%, respectively. Systemic vascular resistance index decreased by 18.8%. We conclude that low-dose infusion of nitroglycerin reduces the pulmonary vascular resistance in patients with pulmonary hypertension, and consequently results in improvement in immediate postoperative hemodynamics after replacement of a stenotic mitral valve.

Adolescent↗
PubMed1991

Characterization of Cobblestone mitral valve interstitial cells.

Mitral valve interstitial cells (MVICs) are important in the structure and function of the valve. In a cell culture system that used explants to harvest MVICs, we found that after several passages, some of the cultures at confluence formed a monolayer of cobblestone-shaped cells (CB type). The rest of the cultures were, however, different, consisting of elongated cells (EL type) that formed overlapping orthogonal patterns. When compared with the MVICs-EL, cells from cultures of MVICs-CB were less adherent to a plastic substratum initially than were MVICs-EL and were more sensitive to trypsinization following culture for 3 to 7 days. Ultrastructurally, the cultures of MVICs-CB showed prominent Golgi's complexes and endoplasmic reticulum and fewer microfilaments when compared with those of MVICs-EL. Most strikingly, the CB cells contained much less alpha-smooth-muscle cell actin compared with that of EL cells. The MVICs-CB were not endothelial cells as they did not show the characteristic dense peripheral band that was present in endothelial cells in a confluent monolayer and showed only trace amounts of fluorescence when incubated with 1,1-dioctadecyl 1-3,3,3,3 tetramethyl-indocarbocyanine-percholate (Dil-)--acetylated low-density lipoprotein compared with large amounts of fluorescence with endothelial cells. Cells that were morphologically similar to MVICs-CB were present in the in vivo valve as well and also formed small islands of cells even in the primary cultures that grew out of the explant. The findings supported the hypothesis that MVICs-CB represent a distinct phenotype of the MVICs that is different from that of the MVICs-EL and is not that of either endothelial or medial smooth-muscle cells.

Actin Cytoskeleton↗
PubMed1994

Cost-effectiveness of infective endocarditis prophylaxis for mitral valve prolapse with or without a mitral regurgitant murmur.

To assess the cost-effectiveness of prevention of infective endocarditis (IE) and to calculate cost-effectiveness of currently recommended regimens in patients with mitral valve prolapse (MVP), data on risk of death, complications, and health-care use, and cumulative incremental health-care costs due to the occurrence of IE were combined with data on the prevalence and manifestations of MVP, estimated years of life lost, and efficacy of antibiotic prophylaxis. Effectiveness and costs of standard endocarditis prophylaxis regimens were calculated per IE case prevented and years of life saved. Under the most likely scenario, oral amoxicillin prophylaxis for all MVP patients would prevent 32 cases of IE per million dental procedures at approximate costs of $119,000 per prevented case and $21,000 per year of life saved. Limiting prophylaxis to patients with mitral murmurs would prevent 80 cases of IE per million procedures at costs of about $19,000 per prevented case and $3,000 per year of life saved. Erythromycin prophylaxis was slightly less expensive than amoxicillin per benefit because of lower cost and lack of drug anaphylaxis, whereas intravenous ampicillin was 7 to 30 times more costly. Sensitivity analyses suggested that erythromycin prophylaxis might be cost-saving under some scenarios, whereas intravenous ampicillin use might cause net loss of life. Thus, prevention with oral antibiotics of the cumulative morbidity and incremental health care costs due to IE in MVP patients is reasonably cost-effective for MVP patients with mitral murmurs.

Adult↗
PubMed1994

Clinical and health care cost consequences of infective endocarditis in mitral valve prolapse.

Although mitral valve prolapse (MVP) predisposes to infective endocarditis (IE), both the clinical consequences of IE and the increment in health care costs it imposes on patients with MVP remain uncertain. Accordingly, 21 MVP patients with IE and 41 age- and sex-matched control subjects with initially uncomplicated MVP were followed (95% complete) a mean of 8 years. Outcomes included death, complications, health care use and cumulative incremental costs. More MVP patients with IE died (25 vs 5%, p < 0.05), underwent valve surgery (40 vs 8%, p < 0.01), had heart failure (50 vs 5%, p < 0.01) or embolization (53 vs 11%, p < 0.01), underwent cardiac catheterization (40 vs 13%), and saw their physicians > 2 times per year (88 vs 33%). The cumulative incremental cost of IE (1990 dollars) was $46,132 per case. Thus, IE in patients with MVP causes considerable cumulative morbidity and incremental health care costs.

Adult↗
PubMed2001

Atrial natriuretic factor and mitral valve prolapse syndrome.

Mitral valve prolapse (MVP), is the most frequent valvulopathy, although it is difficult to evaluate its incidence since this pathology is often asymptomatic. However, in some patients a rich variety of symptoms such as chest pain, dyspnea, palpitations, syncope, dizziness, panic attacks and autonomic dysfunctions have been found. The pathogenesis of these symptoms, incompletely understood, appears to be multifactorial, related to altered autonomic function, adrenergic responsiveness and to combinations of these factors. In patients with MVP a variety of neuroendocrine anomalies has been found: high epinephrine and norepinephrine plasma levels, altered rennin-angiotensin-aldosteron (RAA) response to volume depletion and orthostatic stimulation, and high plasma levels of atrial natriuretic factor (ANF) especially in hypovolaemic individuals. The role of ANF could be important in the genesis of MVP syndrome, it could contribute to determine: the imbalance between the sympathetic and parasympathetic system, the altered RAA response to orthostatic stimulus, the volemic and venous flow reductions (with a direct action, other than diuretic and natriuretic action). Factors that can determine ANF secretion abnormality in MVP could be: 1) Mitral regurgitation; 2) increased heart rate and the high incidence, in MVP syndrome, of arrhythmias; 3) central nervous system neuroendocrine imbalance; 4) increased catecholamines secretion.

Atrial Natriuretic Factor↗
PubMed2006

Finite-element-method (FEM) model generation of time-resolved 3D echocardiographic geometry data for mitral-valve volumetry.

INTRODUCTION: Mitral Valve (MV) 3D structural data can be easily obtained using standard transesophageal echocardiography (TEE) devices but quantitative pre- and intraoperative volume analysis of the MV is presently not feasible in the cardiac operation room (OR). Finite element method (FEM) modelling is necessary to carry out precise and individual volume analysis and in the future will form the basis for simulation of cardiac interventions. METHOD: With the present retrospective pilot study we describe a method to transfer MV geometric data to 3D Slicer 2 software, an open-source medical visualization and analysis software package. A newly developed software program (ROIExtract) allowed selection of a region-of-interest (ROI) from the TEE data and data transformation for use in 3D Slicer. FEM models for quantitative volumetric studies were generated. RESULTS: ROI selection permitted the visualization and calculations required to create a sequence of volume rendered models of the MV allowing time-based visualization of regional deformation. Quantitation of tissue volume, especially important in myxomatous degeneration can be carried out. Rendered volumes are shown in 3D as well as in time-resolved 4D animations. CONCLUSION: The visualization of the segmented MV may significantly enhance clinical interpretation. This method provides an infrastructure for the study of image guided assessment of clinical findings and surgical planning. For complete pre- and intraoperative 3D MV FEM analysis, three input elements are necessary: 1. time-gated, reality-based structural information, 2. continuous MV pressure and 3. instantaneous tissue elastance. The present process makes the first of these elements available. Volume defect analysis is essential to fully understand functional and geometrical dysfunction of but not limited to the valve. 3D Slicer was used for semi-automatic valve border detection and volume-rendering of clinical 3D echocardiographic data. FEM based models were also calculated. METHOD: A Philips/HP Sonos 5500 ultrasound device stores volume data as time-resolved 4D volume data sets. Data sets for three subjects were used. Since 3D Slicer does not process time-resolved data sets, we employed a standard movie maker to animate the individual time-based models and visualizations. Calculation time and model size were minimized. Pressures were also easily available. We speculate that calculation of instantaneous elastance may be possible using instantaneous pressure values and tissue deformation data derived from the animated FEM.

Echocardiography, Three-Dimensional↗
PubMed1986

Magnesium deficiency in the pathogenesis of mitral valve prolapse.

Idiopathic mitral valve prolapse (MVP) is the commonest valvular disorder in industrialized nations. It is predominantly a familial condition, showing Mendelian dominance with delayed and variable penetrance. Although hyperkinesis and hypertrophy of the left ventricle have been described in MVP, its histopathology, somatic morphology and genetics support the leading theory that MVP results from a hereditary disorder of connective tissue. Latent tetany (LT) due to chronic Mg deficit (Mg-D) occurs in over 85% of MVP cases; MVP complicates 26% of LT. Mg-D can explain many clinical features of the MVP syndrome which are not easily explained by its genetics. Mg-D hinders the mechanism by which fibroblasts degrade defective collagen, increases circulating catecholamines, predisposes to cardiac arrhythmias, thromboembolic phenomena and dysregulation of the immune and autonomic nervous systems. Mg therapy provides relief of MVP symptoms.

Alprostadil↗
PubMed2007

Medication use and symptoms in individuals with mitral valve prolapse syndrome.

Mitral valve prolapse (MVP) is a common valvular heart disease associated with a variety of frightening symptoms. Beta-adrenergic blockers along with calcium channel blockers and anxiolytics are widely used to treat symptoms associated with MVPS despite a lack of evidence that supports their efficacy. This study examined the relationship between prescribed medication use and frequency and intensity of MVPS symptoms. A descriptive cross-sectional survey design was used. Descriptive statistics and Cramér's V correlational analysis were used to answer the research questions. Self-completed questionnaires were mailed to 2,282 MVPS individuals older than 21 years of age throughout the United States and Canada previously diagnosed with MVPS. Of the 837 participants, 337 (40%) were taking one or more medications. Although there were significant positive correlations between anxiety and calcium channel blockers, chest pain and digoxin, and mood swings and digoxin, the correlations were very weak.

Adrenergic beta-Antagonists↗