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At least 433 records · Page 24Linked to original sources
PubMed1993

Rapid increase in plasma endothelin concentrations during percutaneous balloon dilatation of the mitral valve in patients with mitral stenosis.

OBJECTIVE: To investigate the relation between plasma concentrations of immunoreactive endothelin and haemodynamic variables before and after percutaneous transvenous balloon dilatation of the mitral valve. DESIGN: Prospective study. SETTING: National cardiovascular centre. PATIENTS: 25 patients with mitral stenosis and 26 healthy volunteers. MAIN OUTCOME MEASURES: Plasma concentrations of immunoreactive endothelin were measured in the pulmonary artery, left atrium, ascending aorta, and femoral vein before and after balloon dilatation of the mitral valve. RESULTS: Peripheral venous concentrations (mean (SD)) of endothelin were higher in the patients with mitral stenosis than in the healthy volunteers (1.76 (0.51) v 1.37 (0.45) pg/ml, p < 0.05) and they correlated with the mean left atrial pressure (r = 0.74, p < 0.01). Balloon dilatation of the mitral valve reduced the mean left atrial pressure without changing the mean right atrial pressure, systemic arterial pressure, heart rate, or cardiac index. Concentrations of plasma endothelin in the femoral vein increased from 1.76 (0.51) to 3.39 (2.46) (p < 0.01), 4.82 (2.34) (p < 0.001), and 2.43 (0.52) pg/ml (p < 0.05) at 15 and 30 minutes and 24 hours after the procedure. The concentration of endothelin in the pulmonary artery also increased from 1.85 (0.85) to 4.32 (1.58) pg/ml (p < 0.01) 30 minutes after the dilatation, whereas there were no appreciable changes in endothelin concentration in the left atrium or ascending aorta. CONCLUSIONS: Plasma endothelin concentrations were higher in patients with mitral stenosis than in healthy volunteers and the increase was proportional to left atrial pressure. After balloon dilatation of the mitral valve there was an abrupt rise in endothelin in the femoral vein and pulmonary artery but no change in left atrial or aortic blood samples. These findings suggest that endothelin may be another vasoactive substance involved in congestive heart failure.

Adult↗
PubMed2002

Mitral valve replacement in ischemic mitral regurgitation. Preservation of both anterior and posterior mitral leaflets.

BACKGROUND: The surgical risks associated with ischemic mitral regurgitation are thought to be greater than those for other forms of mitral regurgitation. We have performed mitral valve replacement using the St. Jude Medical bileaflet prostheses with preservation of both leaflets, along with all of the chordae tendineae and papillary muscles. The aim of this study was to retrospectively evaluate mitral valve replacement with preservation of both mitral valves with respect to long-term clinical results and left ventricular performance. METHODS: Between January 1, 1988 and February 29, 2000, 15 patients were operated on for ischemic mitral regurgitation. There were 7 males and 8 females, and the mean age was 69.7+/-8.1 years. The preoperative variables showed clinical deterioration of the state, such as emergency operation in 40% of the patients, more than NYHA functional III class in 93% of patients, cardiogenic shock in 47% of the patients, a mean left ventricular ejection fraction of 36.8%, and a mean left ventricular end-systolic volume index of 116.7 ml/m2. RESULTS: There were 5 (33.3%) hospital deaths during the follow-up period including 1 early death and 1 (10%) late death during the follow-up period. Thus, the actuarial survival rate after 5 years for the whole was 60%. However, the left ventricular dimensions and left ventricular fractional shortening, even if in patients with profound depressed left ventricular function preoperatively, showed maintenance of the cardiac function. CONCLUSIONS: These results suggested that mitral valve replacement using the St. Jude Medical prostheses with preservation of both leaflets and all chordae tendineae and papillary muscles might be a procedure of choice for ischemic mitral regurgitation.

Aged↗
PubMed2006

[Mitral valve prolapse].

Mitral valve prolapse (MVP) is still a clinical challenging problem. In this report, we review the main characteristics of this entity. Epidemiology of MVP, which relies on the diagnostic criteria adopted, and the incidence of complications, both arrhythmic and structural, are influenced by the characteristics of the population studied, which may lead to bias in data interpretation. Even the definition of MVP may differ according to the cardiologist's or cardiac surgeon's point of view. Usually, cardiologists define MVP as the protrusion of all or part of the mitral leaflets into the left atrium, independent of maintenance of coaptation. Therefore, using this definition, mitral regurgitation is considered as a complication rather than a diagnostic criterion. Arrhythmias, either supraventricular or ventricular, are other possible complications, mostly not life-threatening and associated with myxomatous degeneration of the valve. Diagnosis of MVP is based on echocardiography, which provides detailed anatomic and functional evaluation of the affected valve. Leaflet thickness and motion as well as presence and severity of mitral regurgitation can be assessed, with important diagnostic and prognostic implications. Echocardiographic evaluation of the mitral valve requires a systematic approach in order to define the leaflet/scallop involved and the mechanisms of mitral regurgitation. To this aim, three-dimensional reconstruction may add further insights into objective rendering of mitral valve pathology. Finally, surgical timing in mitral regurgitation due to MVP is an evolving issue and the likelihood of surgical repair is a crucial factor in the optimal timing of surgical intervention, especially in asymptomatic patients with severe mitral regurgitation.

Echocardiography, Three-Dimensional↗
PubMedDate not supplied

Assessment of normal and abnormal prosthetic mitral valves by Doppler echocardiography. Doppler in prosthetic mitral valves.

Pulsed, continuous-wave, and color Doppler were performed in 165 normal mitral prostheses and 58 patients with prosthetic dysfunction (46 regurgitant and 12 obstructive valves) proved by catheterization and/or surgery. Mean mitral gradient (MG) and pressure half-time (PHT) were determined in all cases. Among normal prostheses, a wide range of both MG and PHT was observed in each type of valve and a considerable overlap between valves of different size. St-Jude's valve had the most optimal hemodynamics. Mild mitral insufficiency was detected in 14% of tissue and 24% of mechanical mitral valves. Repeat studies were performed in 30 patients over a 2.4 years period. Nine patients developed Doppler evidence of new prosthetic dysfunction, while Doppler parameters remained unchanged in 21 patients during the follow-up period. Among malfunctioning valves, Doppler correctly identified all cases of prosthetic obstruction (n = 12), and 42 of 46 regurgitant valves. We conclude that Doppler echocardiography is a very useful technique in both non-invasive assessment and follow-up of normal prosthetic valves in the mitral position and in detecting prosthetic dysfunction, especially when prosthetic obstruction is present.

Adolescent↗
PubMed2006

Mitral valve repair: an in-vitro comparison of the effect of surgical repair on the pressure required to cause mitral valve regurgitation.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare mitral valve repair techniques in vitro. Rupture or elongation of the mitral valve chordae tendineae is a known cause of mitral regurgitation, and can be corrected by edge-to-edge repair, chordal replacement, or chordal transposition. METHODS: A test apparatus was used to apply pressure to porcine mitral valves. Mitral valve specimens were tested intact (n = 50), after they had been experimentally damaged, and after repair. Each test was repeated ten times. Experimental damage consisted of severing either the anterior leaflet strut, and attached marginal chordae (n = 30) or posterior leaflet chordae (n = 20). Valves with damaged anterior leaflets were repaired by either: (i) edge-to-edge repair; (ii) chordal replacement; or (iii) chordal transposition. Valves with damaged posterior leaflets were repaired by the first two techniques. Each repair method was repeated on ten specimens. RESULTS: Mitral valves repaired using the edge-to-edge repair (p = 0.002) and chordal replacement (p = 0.038), after rupture to anterior leaflet chordae, recovered significantly better than specimens repaired by chordal transposition. There was no statistical difference in recovery between edge-to-edge repair and chordal replacement (p > 0.05). There was no statistical difference (p > 0.05) in the recovery of the pressure withstood by valves repaired by edge-to-edge repair and chordal replacement, after rupture of posterior leaflet chordae. CONCLUSION: These results showed that edge-to-edge repair and chordal replacement are well suited for the repair of both the anterior and posterior leaflets.

Animals↗
PubMed1990

Intraoperative transesophageal color-coded Doppler echocardiography for evaluation of residual regurgitation after mitral valve repair.

Because mitral valve competence after mitral valve reconstruction is awkward to assess during this procedure, we evaluated in this respect transesophageal color-coded Doppler echocardiography in 23 patients undergoing mitral valve reconstruction for severe mitral regurgitation. Transesophageal echocardiographic examinations were performed after induction of anesthesia but before sternotomy (baseline), after mitral valve repair before decannulation, and at sternal closure, all at similar mean aortic pressure and echocardiographic instrument settings. The degree of mitral regurgitation by transesophageal color Doppler flow mapping was visually quantified on a 5-point scale (0 to 4), pending the left atrial extent of the regurgitant jet. This was compared with the degree of mitral regurgitation by left ventricular cineangiography performed within several weeks after operation and also visually quantified on a 5-point scale (0 to 4), with use of the right anterior oblique projection. There was good correlation between the two methods (r = 0.83; p less than 0.001). We conclude that residual mitral regurgitation, as assessed by transesophageal color flow mapping in the operating room, highly correlates with the ultimate mitral regurgitation by cineangiography. Therefore transesophageal echocardiography can be helpful for evaluation of mitral valve competence during mitral valve reconstruction, and hence, in case of repair failure, allow valve replacement in the same surgical session, thus avoiding reoperation.

Adolescent↗
PubMed1982

[Vectorcardiographic analysis of atrial activation in isolated mitral valve prolapse. Atrial vectorcardiography in prolapsed mitral valve].

The purpose of our work is to study atrial depolarization in primary mitral prolapse (MVP), since, as far as we know, such a study has never been performed. Thirty patients with MVP were studied: 23 females, aged 37,3 +/- 15,5 years and 7 males, aged 45.1 +/- 18.1 years. MVP was diagnosed by M-mode echocardiography. Atrial depolarization was analysed on photographically recorded Frank's vectorcardiograms. On PsE loops, magnitude and direction of maximum planar vector (VMax) in the frontal (F) and left sagittal (LS) planes, magnitude and direction of anterior (HV1) and posterior (HV2) vectors in the horizontal (H) plane, HV1 to HV2 amplitude ratio and total atrial activation time (T) were measured. This last value (T), measured on vectorcardiographic records, was confirmed by high-speed (200 mm/sec) electrocardiograms. These data were compared, by mean of Student's test, with those measured on records obtained from a similar group of normals. The following statistically significant (P less than 0.05) differences were detected: decreased amplitude of VMax in F (0.11 +/- 0.03 vs. 0.080 +/- 0.03) and LS (0.11 +/- 0.03 vs. 0.085 +/- 0.03), backward shift of HV2 (+65 degrees +/- 39 degrees vs. + 11 degrees +/- 35 degrees) and decreased T (98 +/- 25 vs. 85 +/- 17). The decrease of total atrial activation time, about 13% less than in normals, is the most interesting finding of our research. Such an alteration of atrial depolarization can be explained by inter- and/or intra-atrial conduction disturbance, on anatomical or functional base. Therefore, our findings are consistent either with the hypothesis that MVP is secondary to widespread pathological changes or with the one that MVP is a consequence of neurovegetative imbalance.

Adolescent↗
PubMed2004

Marfan syndrome and mitral valve prolapse.

Mitral valve prolapse (MVP), an abnormal displacement into the left atrium of a thickened and redundant mitral valve during systole, is a relatively frequent abnormality in humans and may be associated with serious complications. A recent study implicates fibrillin-1, a component of extracellular matrix microfibrils, in the pathogenesis of a murine model of MVP. This investigation represents an initial step toward understanding the mechanisms involved in human MVP disease and the development of potential treatments.

Animals↗
PubMed1985

Effects of mitral valve replacement on ventilation, volumes, diffusing capacity and regional perfusion of lungs in patients with mitral valve disease.

The effects of mitral valve replacement on ventilation, lung volumes, diffusing capacity and regional perfusion of the lungs were studied in eight patients with long-standing mitral valve disease. Eight patients of the same age with coronary artery disease who underwent coronary bypass operation were tested as controls. Preoperatively, the patients with mitral valve disease had significantly higher perfusion of the upper lung fields and the ratio of residual volume to total lung capacity than the control patients. Vital capacity, forced expiratory volume in one second and maximal expiratory flow at 50% of vital capacity were lower in comparison with the control group. Seven days after open heart surgery the values of all the parameters mentioned above had decreased significantly from the preoperative levels in both groups. Three months post-operatively, the values returned to preoperative levels. The abnormal overperfusion of the upper lung fields and other derangements in the ventilatory pattern did not subside even though cardiac haemodynamics were corrected by mitral valve replacement.

Adult↗
PubMed1994

[Value of the superior trans-septal approach in mitral valve replacements].

Mitral valve exposure is widely improved by the superior-transseptal approach (STS). The diffusion of this technique has been restricted because of the possibility of detrimental effects of sino-atrial arrhythmias, especially in patients in sinus rhythm preoperatively. Between April 1991 and December 1992, we performed mitral valve replacement (MVR) on 55 patients by an STS approach. The mean age was 57.7 +/- 11.3 years (38-75 years). 21 were reoperations and 1 patient had been operated twice. The procedure consisted in 10 MVR with a bioprosthetic valve and 45 with a mechanical valve. Associated procedures were 5 tricuspid annuloplasties, 13 aortic valve replacements, 1 tricuspid valve replacement, 4 CABG, and 1 aneurysm resection. Overall hospital mortality was 9.1 +/- 3.8% (5/55). Mortality for isolated MVR was 6.2 +/- 4.2% (2/32). 51% (28/55) were in sinus rhythm (SR) preoperatively, 43% (12/28) of them had never presented atrial fibrillation. Postoperatively among those 28 patients in SR, 20 remained in SR, 7 were in atrial fibrillation, and 1 in atrial flutter. 3.6% (2/55) needed transient electrosystolic pacing for very slow atrial fibrillation 20% (11/55) have presented a transient sino-atrial dysfunction; None of these rhythmic events had any adverse effect. Finally, the very good visibility and accessibility are the major advantages of this approach, especially in mitro-tricuspid combined procedures, in small left atrium and repeat surgery. As sino-atrial arrhythmias are transient, we think this approach can be routinely employed in MVR.

Adult↗
PubMed1991

[A case of mitral valve replacement due to mitral regurgitation after percutaneous transvenous mitral commissurotomy (PTMC)].

A 58-year-old woman, who had congestive heart failure due to mitral regurgitation after percutaneous transvenous mitral commissurotomy, underwent mitral valve replacement. It is reported that mitral regurgitation more often occurs after PTMC in patients with severely calcified mitral valve or advanced subvalvular lesion than in those without. Our experience indicated that PTMC should be carefully performed in institutions which have a surgical team ready for emergency operation.

Catheterization↗
PubMed1990

Use of enoximone in weaning from cardiopulmonary bypass following mitral valve surgery.

Mitral valve surgery is often complicated by a postoperative low cardiac output state. In addition, some patients may have pre-existing pulmonary hypertension. Conventional inotropes, such as dopamine and dobutamine, tend to increase pulmonary vascular resistance. However, enoximone has both inotropic and vasodilatory properties. Ten patients, who had undergone mitral valve surgery and in whom weaning from cardiopulmonary bypass was unsuccessful without inotropic support, were treated with enoximone, 1 mg/kg loading dose plus 10 micrograms/kg/min continuous infusion, to assist in weaning from bypass. A significant and sustained increase in cardiac index was achieved without an increase in heart rate. At the same time, mean arterial pressure, systemic vascular and pulmonary vascular resistances were significantly decreased.

Aged↗
PubMed1995

Mitral valve prolapse causing severe mitral regurgitation in a patient with absent right pulmonary artery.

A 33-year-old man was investigated for dyspnea on exertion and the presence of a pansystolic murmur. Physical examination revealed dextrocardia confirmed by chest radiograph, which also showed oligemic right lung field. Subsequent cardiac catheterization revealed secundum atrial septal defect, persistent left sided superior vena cava, and severe mitral valve prolapse causing severe mitral regurgitation with pulmonary hypertension. The right pulmonary artery was absent. It is the first report of the association between severe mitral valve prolapse and absent right pulmonary artery.

Adult↗
PubMed1989

Mitral valve prolapse.

Mitral valve prolapse continues to arouse considerable interest because of its worldwide prevalence, lack of unanimity in diagnostic criteria, and association with such potentially serious complications as angina-like chest pain, cardiac arrhythmias, sudden death, progressive mitral regurgitation, cerebral embolism, and infective endocarditis. This review includes a discussion of the prevalence of mitral valve prolapse around the world, a critical review of the diagnostic criteria, and a discussion of the pathophysiology of the important complications, with special emphasis on cardiac arrhythmias.

Humans↗
PubMed1991

Recurrent cerebral infarction during anticoagulation therapy in patients with mitral valve prolapse.

Mitral valve prolapse has been associated with an increased risk of transient or lasting ischemic events. Recurrence is uncommon after initiation of antiplatelet or anticoagulant therapy. In this communication we report two patients, both female, who had mitral valve prolapse as the major risk factor for cerebrovascular disease and who developed cerebral infarction despite anticoagulation. The cerebral infarctions were bilateral and extensive in one patient and led to the patient's death. In the second case, three infarctions resulted in moderate disability.

Adult↗
PubMed1986

Neurologic disorders associated with mitral valve prolapse.

Mitral valve prolapse has been reported to be associated with a variety of neurologic disorders, including cerebral ischemia, transient global amnesia, migraine, autonomic dysfunction, and psychiatric disease. The evidence supporting these associations and possible pathogenetic mechanisms are discussed. Some neurologic disorders may be direct complications of mitral valve prolapse, while others may occur as part of an underlying genetic defect or common link.

Amnesia↗
PubMed1991

Atrial septal occlusion improves the accuracy of mitral valve area determination following percutaneous mitral balloon valvotomy.

We investigated the impact of the atrial communication on the mitral valve area calculation after percutaneous mitral balloon valvotomy in 17 patients (15 women, 2 men; mean age 56 +/- 4 years). The hemodynamic measurements and mitral valve area calculations were performed with and without balloon occlusion of the atrial septal puncture site. The mitral valve area determined with balloon occlusion was significantly smaller than the mitral valve area determined without occlusion (1.6 +/- 0.1 vs. 1.9 +/- 0.1 cm2, P less than 0.01), and was similar to the echocardiographically determined valve area (1.6 +/- 0.1 cm2). This decrease in the calculated mitral valve area with occlusion was associated with a decrease in the measured cardiac output, without a change in the mitral valve gradient or the diastolic filling period. Occlusion of the atrial septal puncture site may permit more accurate determination of the mitral valve area and thus provide a better reference point for future comparison should the question or restenosis arise.

Cardiac Catheterization↗