Unidad Temática N° 1: Estenosis Mitral
 
  1. Ikeda J, Furuyama M, Sakuma T y col. Effects of percutaneous transluminal mitral valvuloplasty on plasma catecholamine levels during exercise. Am Heart J 1993; 126:130.

    2. Elevation of plasma catecholamine levels during exercise in patients with mitral stenosis correlated with the severity of the disease. We investigated the plasma norepinephrine changes in six patients before and after percutaneous transluminal mitral valvuloplasty (PTMV) during continuously graded ergometer exercise. Peak exercise intensity was increased from 65.8 W to 87.5 W after PTMV. Plasma norepinephrine level at 60 W workload intensity was decreased from 2308 +/- 864 pg/ml to 841 +/- 233 pg/ml after PTMV (p < 0.05). We concluded that PTMV decreased the plasma norepinephrine level during exercise in the patients with mitral stenosis. Percutaneous transluminal mitral valvuloplasty is a novel procedure for the improvement of symptoms in patients with mitral stenosis.

     

  2. Yamamoto K, Ikeda U, Mito H y col. Endothelin production in pulmonary circulation of patients with mitral stenosis. Circulation 1994; 89:2093.

    3. BACKGROUND: Although plasma endothelin concentrations are elevated in patients with pulmonary hypertension, the precise sites of endothelin production have not been defined. We investigated the endothelin production in the pulmonary circulation of patients with mitral stenosis and its effects on pulmonary vascular tone. METHODS AND RESULTS: We measured plasma concentrations of endothelin-1, angiotensin II, and thrombomodulin in blood samples obtained from the right and left atria of 10 consecutive patients with rheumatic mitral stenosis (mean age, 55 years; range, 39 to 68) who were undergoing percutaneous mitral valvuloplasty. Plasma levels of endothelin-1 were significantly higher in the left atrium than in the right atrium (3.25 +/- 0.45 versus 2.53 +/- 0.36 pg/mL, mean +/- SE, P < .001). The increased plasma endothelin-1 level in the left atrium, which reflected endothelin-1 production in the pulmonary circulation, was correlated with mean pulmonary artery pressure (r = .65, P = .04), mean pulmonary arterial wedge pressure (r = .67, P = .03), total pulmonary resistance (r = .68, P = .03), and 1/mitral valve area (r = .85, P = .002) but not with pulmonary vascular resistance (r = .04, P = .91). There were no significant differences in plasma levels of angiotensin II and thrombomodulin between the right and left atria (angiotensin II, 16.40 +/- 3.08 versus 15.50 +/- 4.85 pg/mL; thrombomodulin, 2.96 +/- 0.34 versus 2.85 +/- 0.37 ng/mL). CONCLUSIONS: Endothelin-1 production is increased in the pulmonary circulation of patients with mitral stenosis in response to increased pulmonary artery pressure but is not directly related to increased pulmonary vascular tone in this disorder.

     

  3. Barlow J. Functional anatomy of the mitral valve. En: Barlow J. Perspectives on the mitral valve. F.A. Davis Company, 1987:1.

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  4. Horstkotte D, Niehues R, Strauer B. Pathomorphological aspects, aetiology and natural history of acquired mitral valve stenosis. European Heart Journal 1991;12(Supp B):55.

    5. Commissural fusion, leaflet thickening and alteration of the subvalvular apparatus are dominant mechanisms causing clinically important mitral stenosis (MS) of rheumatic origin. Calcification and a consequent decrease in leaflet mobility are subsequent features in rheumatic MS and may be the primary mechanisms in MS of degenerative origin. In 1051 consecutive patients with pure or predominant MS requiring surgical intervention, aetiology was rheumatic in 76.9%, infective in 3.3%, degenerative (severe annular and leaflet calcification) in 2.7% and congenital (Lutembacher syndrome) in 1.2%; it was the result of systemic lupus erythematosus (n = 4), carcinoid heart disease (n = 2), endomyocardial fibrosis (n = 2) and rheumatoid arthritis (n = 2) in less than 1%, while in 14.5% of these patients aetiology remained unclassified. The natural history of rheumatic MS is characterized by an asymptomatic latent period, following the initial rheumatic fever (RF). In a prospective study of MS (n = 159) the mean interval between RF and the appearance of symptoms was 16.3 +/- 5.2 years. Twenty-five years after the initial RF 8% of the patients were still asymptomatic, 9% were class II (NYHA), 33% class III and 50% had been operated or were class IV. Progress from mild to severe disability took 9.2 +/- 4.3 years on average. When valve surgery was indicated but refused by the patients, survival with medical treatment was 0.44 +/- 0.06 after 5 years, 0.32 +/- 0.08 after 10 years and 0.19 +/- 0.09 after 15 years.

     

  5. Marzo KP, Herrmann HC, Mancini DM. Effect of balloon mitral valvuloplasty on exercise capacity, ventilation and skeletal muscle oxygenation. J Am Coll Cardiol 1993;21(4):856

    6. OBJECTIVES. The short- and long-term effects of valvuloplasty on exercise capacity, ventilation and skeletal muscle oxygenation were investigated to determine whether a dissociation between hemodynamic improvement and exercise capacity occurs in patients with mitral stenosis. BACKGROUND. Percutaneous balloon mitral valvuloplasty in patients with mitral stenosis results in immediate hemodynamic improvement at rest and with exercise. Improved exercise capacity has been described at 3 months after valvuloplasty. In patients with left ventricular dysfunction, acute therapeutic interventions that produce hemodynamic benefit do not immediately improve exercise capacity. METHODS. Maximal bicycle exercise with measurement of respiratory gases was performed in 11 patients with mitral stenosis before and at 48 h and 3 months after successful percutaneous balloon mitral valvuloplasty. Respiratory and leg skeletal muscle oxygenation were assessed by monitoring changes in light absorption of the serratus anterior and vastus lateralis muscles using near-infrared spectroscopy and were expressed as percent deoxygenation. RESULTS. Mitral valvuloplasty significantly increased mean mitral valve area from 1.0 +/- 0.2 to 1.7 +/- 0.3 cm2 (p < 0.05). Immediately after valvuloplasty, peak exercise oxygen consumption (VO2), VO2 at the anaerobic threshold, ventilation, peak respiratory and leg muscle deoxygenation all remained unchanged. At submaximal work loads, respiratory muscle deoxygenation was attenuated (25 W: before 12 +/- 4%; 48 h 4 +/- 3%; 50 W: before 10 +/- 5%; 48 h 5 +/- 4%; both p < 0.05). At 3 months, significant improvement in peak VO2 (before 10.9 +/- 5%; 3 months 14.6 +/- 6.2 ml/kg per min; p < 0.05) and VO2 at the anaerobic threshold (before 7.1 +/- 2.4; 3 months 8.4 +/- 2.3; p < 0.05) were observed, whereas ventilation remained unchanged. No further improvement was seen in respiratory muscle deoxygenation. Vastus lateralis deoxygenation at submaximal work loads tended to be decreased. CONCLUSIONS. Long-term changes in skeletal muscle and the lungs preclude immediate enhancement of exercise performance after balloon mitral valvuloplasty. Immediate symptomatic improvement probably results from an immediate decrease in the work of breathing. Long-term symptomatic improvement results from changes that occur in the peripheral skeletal musculature as well as from the reduced work of breathing.

     

  6. Carroll J, Feldman T. Percutaneous mitral balloon valvotomy and the new demographics of mitral stenosis. JAMA 1993; 270: 1731

    OBJECTIVE--This review discusses the latest developments in selected clinical features and catheter-based therapy of mitral stenosis. DATA SOURCES--English-language journal articles and reviews in the clinical and epidemiological literature as related to mitral valve stenosis from 1965 through March 1993, identified by bibliography review and expert consultation. STUDY SELECTION--Selected studies included clinical trials with adequate patient population description and short- and long-term (5 years) follow-up for topics related to mitral valve stenosis in the clinical literature. DATA EXTRACTION--Two reviewers participated in extracting the data with the aim of presenting a balanced and comprehensive review of the subject. DATA SYNTHESIS AND CONCLUSIONS--The main conclusions are (1) mitral stenosis should no longer be viewed as a largely "geriatric disease" in the United States due to a recent inflow many young immigrants from countries where rheumatic fever continues partially or wholly unabated; (2) clinical and anatomical features of mitral stenosis are age-dependent; when clinical presentation occurs at 30 vs 70 years of age, for example, the degree of valve obstruction may be similar but differences exist in the frequency of atrial fibrillation, the magnitude of reduction in cardiac output, the degree of valve deformity and calcification, and the frequency of coexistent coronary artery disease; and (3) mitral stenosis therapy has undergone a reorientation with the introduction of percutaneous mitral balloon valvotomy, which has proven to be safe, cost-effective, and to provide short- and long-term improvements in symptomatic and hemodynamic status in selected patients.

  7. Role of closed mitral commissurotomy in mitral stenosis with severe pulmonary hypertension. Sajja LR, Mannam GC. J Heart Valve Dis 2001 May 10:288-93

    BACKGROUND AND AIMS OF THE STUDY: Closed mitral commissurotomy (CMC) is a well-established method for treatment of rheumatic mitral stenosis, but outcome in patients with severe pulmonary arterial hypertension (PAH) has not been clearly documented. METHODS: Between April 1996 and October 1999, among 61 patients who underwent CMC, 27 had severe PAH (systolic pressure > 100 mmHg). Of these patients, 11 were in NYHA class III, and 16 were in class IV. Preoperatively, the mean pulmonary artery (PA) pressure was 107.85 +/- 5.74 mmHg (range: 100-118 mmHg), mitral valve area (MVA) 0.704 +/- 0.106 cm2 (range: 0.5-0.91 cm2), and transmitral gradient 11.93 +/- 1.54 mmHg (range: 10-15 mmHg). The echocardiographic mitral valve score was 6.37 +/- 1.11 (range: 6-10). RESULTS: There was no operative mortality or incidence of significant (> or = 2+) post-CMC mitral regurgitation or cerebrovascular accident. The MVA increased to 2.385 +/- 0.248 cm2 (range: 1.9-2.8 cm2), the transmitral gradient fell to 2.44 +/- 0.51 mmHg (range: 2-3 mmHg), and postoperative PA systolic pressure fell to 33.33 +/- 8.20 mmHg (range: 30-60 mmHg). During a mean follow up of 26.9 months (range: 11-51 months), 23 patients were in NYHA class I and four were in class II. There were no significant differences in parameters between sexes, but mean male age was five years less than mean female age. CONCLUSION: In the subset of patients with severe PAH, surgical CMC is a safe and effective procedure that results in greater MVA and a more significant and sustained fall in PA pressure compared with reported series of percutaneous balloon mitral valvuloplasty.

  8. Closed commissurotomy versus balloon valvuloplasty for rheumatic mitral stenosis. Tokmakoglu H, Vural KM, Ozatik MA, y col. J Heart Valve Dis 2001 May 10:281-7

    BACKGROUND AND AIM OF THE STUDY: Closed mitral commissurotomy (CMC) and percutaneous mitral balloon valvuloplasty (PMBV) were compared by their initial results and Doppler echocardiographic data obtained at one week and one year after the procedure. METHODS: Of 580 patients with severe rheumatic mitral stenosis, 280 underwent CMC and 300 PMBV. The mean pre-procedural transmitral gradient (TMG) was 21 +/- 6 mmHg in the CMC group and 20 +/- 5 mmHg in the PMBV group (p = 0.6); the mean mitral valve area (MVA) was 1.1 +/- 0.2 cm2 in both groups. RESULTS: Mortality was 0.7% after CMC and 0.3% after PMBV; the primary success rates were 98.3% and 89% respectively (p <0.0001). Two CMC patients and three PMBV patients underwent emergency mitral valve replacement. At the first week, the mean TMG was decreased to 4 +/- 3 mmHg in the CMC group, and to 5.8 +/- 2 mmHg in the PMBV group (p <0.0001). The mean MVA was increased to 2.5 +/- 0.5 cm2 after CMC, and to 2.1 +/- 0.4 cm2 after PMBV (p <0.0001). After one year, TMG was 5.4 +/- 4 mmHg in the CMC group (p <0.0001) and 7.1 +/- 3 mmHg in the PMBV group (p <0.0001); MVA was 2.3 +/- 0.5 cm2 (p <0.0001) and 1.9 +/- 0.4 cm2 (p <0.0001), respectively. The results of CMC were significantly better (p <0.0001) with regard to TMG and MVA at these times. A significant decrease was also seen in mean left atrial diameter and pulmonary artery pressure in both groups (p <0.0001). CONCLUSION: Although satisfactory results can be achieved using either approach, CMC provides a higher primary success rate, greater MVA augmentation, and better technical control during the procedure, while reducing the cost. PMBV shortens in-hospital stay and eliminates the risk imposed by thoracotomy and anesthesia. Therefore, in our practice, when surgical intervention is contraindicated due to associated problems, PMBV may be the preferred approach, but exposure to radiation may be of concern in pregnant patients.

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  9. The role of mitral valve balloon valvuloplasty in the treatment of rheumatic mitral valve stenosis during pregnancy. de Andrade J, Maldonado M, Pontes Jr S, y col. Rev Esp Cardiol 2001 May 54:573-9


    10. OBJECTIVE: To analyze the immediate results and the clinical evolution of a group of fertile age women with rheumatic mitral stenosis, in whom percutaneous balloon mitral valvuloplasty was performed before or during pregnancy. PATIENTS AND METHOD: Eighty-one women with mitral stenosis, submitted to balloon mitral vavuloplasty, were studied. They were divided into three groups, according to their desire of no further pregnancies (group A; n = 19), pregnancy during the follow-up (group B; n = 23) or valvuloplasty was performed during pregnancy (group C; n = 39). Patients from group B and C were controlled during pregnancy, childbirth and puerperium, and the newborns of women in group C were followed from birth to the age of 5 years. RESULTS: Mortality in the three groups was null and the incidence of miscarriage was 2 (8.6%) in group B and 3 (9.1%) in group C. Normal delivery was predominant in group B and delivery by caesarean was predominant in group B. Success was immediate in all the cases. The procedure was repeated in 3 women due to restenosis. The media valvar area rase from 0.93 to 2.05 cm2 in group A, from 1.28 to 2.04 cm2 in group B and from 0.84 to 2.14 cm2 in group C (intergroup p = NS). The functional class improved in the three groups of patients. CONCLUSION: Percutaneous balloon mitral valvuloplasty is an effective, efficient method for the treatment of rheumatic mitral stenosis during pregnancy, after organogenesis, or at any time in a woman's life, as long as it is indicated according to clinical and echocardiographic evaluation criteria.

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