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PubMed1994

Pathology of mitral valve stenosis and pure mitral regurgitation--Part I.

This two-part article examines the histologic and morphologic basis for stenotic and purely regurgitant mitral valves. In Part I, conditions producing mitral valve stenosis are reviewed. In over 99% of stenotic mitral valves, the etiology is rheumatic disease. Other rare causes of mitral stenosis include congenital malformed valves, active infective endocarditis, massive annular calcium, and metabolic or enzymatic abnormalities. In Part II, conditions producing pure mitral regurgitation will be discussed. In contrast to the few causes of mitral stenosis, the causes of pure (no element of stenosis) mitral regurgitation are multiple. Some of the conditions producing pure regurgitation include floppy mitral valves, infective endocarditis, papillary muscle dysfunction, rheumatic disease, and ruptured chordae tendinae.

Calcinosis↗
PubMed1990

Ultrasonic debridement during mitral valve reconstruction for calcified mitral stenosis.

An ultrasonic device in conjunction with open mitral commissurotomy was applied in 8 patients with heavily calcified, stenosed mitral valves. In 6 patients, reconstruction of the mitral valve by debridement of the leaflet calcification with the device was successful. Two patients required valve replacement because of an increase in preexistent mitral regurgitation caused by excessive decalcification. The ultrasonic device proved to be a useful and effective adjunct for salvaging the heavily calcified mitral valve, which would otherwise have to be replaced.

Adult↗
PubMed1993

Multiple organ failure after mitral valve repair with intravascular hemolysis and its recovery due to mitral valve replacement.

We present a patient with evidence of severe intravascular hemolysis after mitral valve repair, an established method for the surgical treatment of mitral valve disease to avoid prosthesis related complications. The coincidence of this uncommon complication with hemodynamic instability due to pre-existing myocardial dysfunction and Gram-negative pneumonia promoted the development of simultaneous dysfunction of liver, kidney and the cardio-respiratory system. Elimination of the source of hemolysis by re-operation with mitral valve replacement on the ninth postoperative day allowed prompt recovery from severe organ dysfunction. Free hemoglobin may have perpetuated progressive organ failure in our patient.

Adult↗
PubMed2005

[Mitral valve replacement for mitral regurgitation caused by papillary muscle head rupture complicating acute myocardial infarction: report of a case].

A 71-year-old female was admitted for acute posterolateral infarction. On the next day of the successful emergency perctaneous coronary intervention, she developed severe dyspnea and was intubated at intensive care unit. Massive mitral regurgitation was detected on color Doppler imaging and left ventricular cardiac failure was increasingly developed. The urgent operation was performed for papillary muscle rupture 18 days after first episode. Head rupture of the posterior papillary muscle was found during surgery and the mitral valve was replaced by a prosthetic valve (SJM # 25). The postoperative course was uneventful and she discharged on 52 days after surgery.

Aged↗
PubMed2006

Left ventricular outflow tract obstruction after bioprosthetic mitral valve replacement with posterior mitral leaflet preservation.

We present a case of transient left ventricular outflow tract obstruction after mitral valve replacement with a high-profile bioprosthesis; only the posterior native mitral valve leaflet was preserved. A 76-year-old woman was admitted to our institution with pulmonary edema. Two weeks earlier, she had undergone mitral valve replacement at our hospital due to severe mitral stenosis and 2+ mitral regurgitation complicated by cardiac failure and atrial fibrillation. The patient was taking digoxin, furosemide, and warfarin at the time of readmission. Echocardiography showed a narrowed left ventricular outflow tract. Doppler echocardiography revealed a peak 64-mmHg gradient between the septum and the strut of the bioprosthesis. The patient was successfully treated medically. This case indicates that the risk of left ventricular outflow tract obstruction after bioprosthetic mitral valve replacement is not always eliminated by removal of the anterior mitral valve leaflet when the posterior mitral leaflet is preserved.

Aged↗
PubMed1981

Abnormal mitral valve coaptation in hypertrophic obstructive cardiomyopathy: proposed role in systolic anterior motion of mitral valve.

Two dimensional echocardiographic evaluation utilizing the apical four chamber and apical long axis views was made in 10 normal subjects and 35 patients with hypertrophic cardiomyopathy, including 16 without and 19 with systolic anterior motion of the mitral valve. Mitral valve leaflets were imaged throughout the cardiac cycle. The normal subjects and the patients with hypertrophic cardiomyopathy without systolic anterior motion demonstrated mitral valve coaptation that seemed to involve the distal tip of the anterior leaflet. In contrast, patients with hypertrophic cardiomyopathy with systolic anterior motion demonstrated abnormal coaptation, so that the posterior leaflet coapted with a mid portion of the anterior leaflet, leaving a distal "residual" anterior leaflet in the left ventricle during systole. A sharp angulation of this distal leaflet in mid systole toward the interventricular septum is thought to represent systolic anterior motion. It is speculated that abnormal mitral leaflet coaptation in necessary for development of leaflet systolic anterior motion, which is correlated with dynamic left ventricular outflow gradients in hypertrophic obstructive cardiomyopathy.

Adult↗
PubMed2005

Transaortic double valve replacement in difficult mitral valve exposure.

Adequate open exposure of the mitral valve is necessary to accomplish reconstruction or replacement of the diseased mitral valve apparatus. The technique employed by most cardiac surgeons for mitral valve access involves median sternotomy and vertical left atriotomy posterior to the interatrial sulcus. However, certain conditions can somethimes make this approach very difficult. Different approaches are discussed with particular emphasis on our case in which the transaortic double valve replacement have been performed.

Aortic Valve↗
PubMed1989

Hemodynamic effects of dobutamine in patients following mitral valve replacement.

Mitral valve replacement is frequently complicated by a low cardiac output syndrome and elevated pulmonary arterial pressures. In the present study, we used dobutamine to increase cardiac index and measured the pulmonary hemodynamic effects in 10 patients with increased pulmonary vascular tone following mitral valve replacement. Using increasing doses of dobutamine up to 10 micrograms.kg-1.min-1, we observed a statistically significant increase in mean cardiac index (from 2.39 +/- .14 liters.min-1.m-2 to 3.52 +/- .33, P less than 0.01) and mean heart rate (from 71.6 +/- 5.2 beats.min-1 to 84.3 +/- 8.1, P less than 0.01). This was associated with stable mean systemic arterial pressures and mean pulmonary arterial pressures. Both mean systemic and pulmonary vascular resistances decreased significantly (from 1210 +/- 99 dynes.sec.cm-5 to 809 +/- 90 [P less than 0.01], and from 195.9 +/- 30.6 dynes.sec.cm-5 to 129.4 +/- 41.2 [P less than 0.01] respectively) with dobutamine. Intrapulmonary shunt flow increased significantly in the five patients studied. Though increases in heart rate and pulmonary shunt flow may limit it use, dobutamine increases cardiac output and decreases pulmonary vascular resistance in patients with increased pulmonary arterial pressure following mitral valve replacement.

Adult↗
PubMed1996

In vitro assessment of prosthetic valve function in mitral valve replacement with chordal preservation techniques.

BACKGROUND AND AIM OF THE STUDY: The importance of chordal preservation techniques in maintaining improved left ventricular function after mitral valve replacement has been well documented clinically. Currently, the choice of prosthetic valve used in chordal preservation is dependent upon the surgeon's preference. However, the transvalvular flow characteristics of common, clinically used prosthetic valves may be influenced by the mitral subvalvular apparatus, and may result in degraded valve function. The goal of this study was to perform an in vitro evaluation of the influence of chordal preservation on the transvalvular and left ventricular flow patterns of common valve prostheses. METHODS: Tissue and mechanical valves have been evaluated under physiologic pulsatile flow with anterior and/or posterior chordal preservation. Flow patterns were assessed by 2-D planar flow visualization, pulsed wave Doppler velocity measurements, 2-D echocardiography, and selected color Doppler flow mapping. Based on changes in transvalvular and left ventricular flow patterns, favorable prosthetic valve/chordal preservation combinations were identified. Additionally, valve orientation was varied to determine optimal orientation. RESULTS: Baseline results without chordal preservation indicate that the anti-anatomic orientation is preferred for the bileaflet valve design while the tilting disc valve should be oriented with the major axis toward the posterior (free) wall of the ventricle, corroborating published conclusions by other investigators. Some form of flow restriction is observed in all test cases with chordal preservation due to the presence of the subvalvular tissue. In general, bioprostheses showed less flow restriction then the mechanical valves, particularly with lateral flow expansion. This flow restriction may influence pressure recovery downstream of the mechanical valves tested. Increased flow constriction is observed with anterior and posterior chordal preservation. CONCLUSIONS: This study favors the use of the St. Jude Medical bileaflet valve orientated in the anti-anatomic position, or the Carpentier-Edwards pericardial valve with chordal preservation.

Bioprosthesis↗
PubMed1994

[Successful mitral valve replacement in multiple organ failure due to mechanical hemolytic anemia after mitral valve repair: a case report].

An 18-year-old man suffered multiple organ failure due to hemolytic anemia after mitral valve repair. He was admitted with mitral regurgitation (MR) and mitral valve repair was performed. However, after 3 days of the operation, he developed hemolytic anemia and heart murmur. A reoperation of mitral valve replacement was performed because of progressing heart failure with renal and liver dysfunction. The operative findings revealed a rupture in the choldae with dislocation of the C-E ring. The MR flow and dislocated ring are suspected to be the cause of the hemolysis. After the reoperation, the hemolysis and general condition were immediately improved. The indication of this reoperation should be carefully decided. In this case of multiple organ failure following mitral valve repair, reoperation of mitral valve replacement was successful.

Adolescent↗
PubMed1997

Accuracy and cost-effectiveness of exercise echocardiography for detection of coronary artery disease in patients with mitral valve prolapse.

Mitral valve prolapse is sometimes associated with chest pain, but this symptom may also be caused by coexisting coronary disease. The accuracy of exercise echocardiography in diagnosing coronary disease in these patients and the most cost-efficient diagnostic approach are unclear. We studied 96 patients (aged 59 +/- 12 years; 70 men) with mitral valve prolapse who underwent exercise electrocardiography, exercise echocardiography, and coronary angiography. The accuracies of seven diagnostic strategies based on the current and expected use of exercise electrocardiography and exercise echocardiography in patients with mitral valve prolapse were examined, with the costs calculated based on Medicare reimbursement. Thirteen (13.5%) patients had significant coronary artery disease. The sensitivity and specificity of exercise electrocardiography in the 71 patients with interpretable electrocardiograms were 50% and 72%, respectively. For the 73 patients who achieved >85% of maximal heart rate, 52 had interpretable exercise electrocardiograms (sensitivity 50%; specificity 69%). Exercise echocardiography had a sensitivity of 69% and a specificity of 98% in the 96 patients and a sensitivity of 82% and a specificity of 96% in patients who achieved >85% of maximal heart rate. Approaches adopting Bayes' theorem and restricting further investigation to patients with at least intermediate pretest probability of coronary disease were the least costly. When combined with exercise echocardiography as the initial test, clinical stratification was associated with a false-negative rate of 21%. The utility of exercise electrocardiography is limited by the high prevalence of resting electrocardiographic abnormalities and suboptimal sensitivity and specificity. The best balance of cost and diagnostic accuracy is to perform exercise echocardiography in patients with at least intermediate probability of coronary artery disease.

Aged↗
PubMed1987

Biochemical characterization of individual normal, floppy and rheumatic human mitral valves.

Human mitral valves (32 floppy and 17 rheumatic) obtained at surgery were analysed and compared with 35 normal (autopsy) valves. Total amounts of collagen, proteoglycan and elastin were increased approx. 3-fold in floppy and rheumatic valves. The water content of rheumatic cusps was lower than normal. The most significant changes in floppy valves were the 59% increase in mean value of the proteoglycan content, a large increase in the ease of extractability of proteoglycans from 26.7 to 57.2% of the total and a 62% increase in mean value of the elastin content in the anterior cusps. Normal human mitral valve cusps contained a mean proportion of 29.3 (and chordae 26.6) type III collagen (as % of total types III + I collagen), the values increasing significantly to 33.2 and 36.3% respectively in chronic rheumatic disease. The ratio observed in floppy valves depended on the extent of secondary surface fibrosis, which could be demonstrated histologically; in valve cusps with considerable secondary fibrosis, the percentage of type III increased significantly (to 34.4%), whereas it decreased significantly (to 25.2%) when fibrosis was negligible. It is concluded that the ratio of collagen types in floppy valves reflects the extent of secondary fibrosis rather than the pathogenesis of the disrupted collagen in the central core of the valve.

Amino Acids↗
PubMedDate not supplied

Mitral valve repair for nonrheumatic mitral regurgitation.

BACKGROUND: We studied the results of mitral valve repair in patients with severe mitral regurgitation of nonrheumatic etiology. METHODS AND RESULTS: Between January 1988 and April 2002, 116 patients, of which 59 were male and 57 female, with severe mitral regurgitation of nonrheumatic etiology, underwent mitral valve repair using a variety of techniques. Their mean age was 26.4 years (range 2-67 years). The cause of mitral regurgitation was congenital in 56 patients, myxomatous in 44, infective endocarditis in 7, and ischemic in 9. Ninety patients were in preoperative New York Heart Association class III, and 26 in class IV. Reparative procedures included posterior teflon felt collar annuloplasty (modified Cooley's) in 80 patients, chordal shortening in 37, cusp excision in 34, cleft closure in 8, chordal transfer in 6, and neochordae in 3. The early mortality was 3.4% (4 patients). Follow-up ranged from 1 to 167 months (mean 47 months), and was 95% complete. There were 2 late deaths (1.7%). Six patients (5.2%) underwent reoperation for severe mitral regurgitation post-repair. Of the remaining 104 patients, 90 (86.5%) had no or trivial mitral regurgitation at the last follow-up. Actuarial, reoperation-free, and event-free survival at 130 months was 93%+/-3.6%, 89.9%+/-6%, and 69.7%+/-13.7%, respectively. Ninety-two patients (88.5%) were in New York Heart Association class I at the last follow-up. CONCLUSIONS: Mitral valve repair in nonrheumatic mitral regurgitation patients provides satisfactory results with current surgical techniques, and is the preferred option in this subset of patients.

Adult↗
PubMed2001

[Validation of quantitative parameters of paraprosthetic mitral valve regurgitation of the zone of convergence by transthoracic echocardiography].

The study of the convergence zone by echocardiography is a validated method of quantification of native valve mitral regurgitation. However, there is little data concerning its applications to paraprosthetic mitral regurgitation. The aim of this study was to evaluate the method in this indication. Thirty consecutive patients (21 mechanical and 9 bioprostheses) with paraprosthetic mitral regurgitation quantified by transoesophageal echocardiography were included: 4 mild, 13 moderate and 13 severe. The regurgitant volume RV) and the regurgitant surface area (RSA) were calculated by the following formulae: RV = 2 pi.r2.Va.t.alpha/180 and RSA = RV/VTI (r: mid systolic radius of the convergence zone, Va: aliasing velocity, t: regurgitation time, alpha/180: the angular correction due to parietal stress, VTI: velocity time integral of the regurgitant flow). The feasibility of the calculation of the RV and RSA was 93 and 63% respectively. There was a statistically significant correlation between the RV and transoesophageal echocardiography (r: 0.85, p < 0.001), between RSA and transoesophageal echocardiography (r: 0.67, p < 0.05) and between RV and RSA (r: 0.95, p < 0.001). When severe paraprosthetic regurgitation was defined by a RV greater than 60 ml and RSA greater than 40 mm2, the concordance between RV, RSA and transoesophageal echocardiography was 75% and 74% respectively. Therefore, the study of the convergence zone provides an accurate evaluation of paraprosthetic mitral regurgitation by transthoracic echocardiography.

Adult↗
PubMed1997

[Preventive concomitant aortic root replacement for annuloaortic ectasia in a patient with Marfan syndrome undergoing mitral valve replacement for mitral regurgitation].

A 28-year-old woman presented with Marfan syndrome combined with severe mitral regurgitation and annuloaortic ectasia. The ascending aorta was dilated to 48 mm in diameter without aortic regurgitation. Considering the increased operative risk due to complication with aortic dissection, simultaneous replacement of the mitral valve and aortic root were performed. Her postoperative course was uneventful. Several options of the surgical treatment for Marfan syndrome are discussed.

Adult↗
PubMed1993

Haemodynamic effects and comparison of enoximone, dobutamine and dopamine following mitral valve surgery.

Mitral valve surgery may be complicated by a post-operative low output state requiring inotropic support, and a wide variety of factors may influence the choice of agents used to treat this condition. The authors have examined and compared the haemodynamic effects of the highly specific phosphodiesterase inhibitor enoximone, and the adrenergic agents dobutamine and dopamine in patients undergoing mitral valve surgery. Enoximone, 0.5 mg kg-1 bolus, followed by a continuous infusion of 5 micrograms kg-1 min-1, was compared against dobutamine, 7 micrograms kg-1 min-1, and dopamine, 5 micrograms kg-1 min-1, with the protocol allowing for an increase in the infusion rate by a factor of two if clinical and haemodynamic measurements indicated. All 25 patients receiving enoximone were successfully weaned from cardiopulmonary bypass at the first attempt, with significant increases in cardiac index and stroke index, combined with little or no change in heart rate or pulmonary artery pressures and a highly significant reduction in systemic vascular resistance, and a reduction in mean arterial pressure. Three of the 25 patients receiving dobutamine were withdrawn from the study because of inadequate haemodynamic response, while the remaining 22 patients demonstrated significant increases in heart rate, cardiac index and stroke index, with a reduction in systemic vascular resistance. Nine of the 25 patients receiving dopamine failed to respond adequately, while the remaining 16 demonstrated an increase in heart rate and cardiac index but with little change in stroke index and a modest reduction in systemic vascular resistance. Enoximone has been shown to be a highly effective first-line inotrope in patients following mitral valve surgery with significant advantages over dobutamine and dopamine.

Adult↗
PubMed1988

Correlation between left ventriculography, auscultation, and M-mode and two-dimensional echocardiography in mitral valve prolapse.

Mitral valve prolapse (MVP) is a common valvular abnormality which is observed in as many as 5% of the general population. Although invasive as well as noninvasive tools have been developed to determine the existence of this disorder, none is perfect and false negative as well as false positive diagnoses abound. Because MVP is a relatively benign disorder, it has also not been easy to make the usual clinical-pathological correlations. Left ventriculography is considered by many to be the gold standard, but this designation is probably not deserved. The angiographic criteria used by most do not permit unequivocal separation of normal mitral valve systolic bulging from pathologic MVP, and the interobserver and intraobserver variability of interpretation is high. However, false positive diagnoses can be eliminated if MVP is diagnosed only when para-annular displacement of mitral leaflet tissue is detected during systole rather than simple leaflet bulging. Although mid-systolic clicks and late systolic murmurs have proven to be the auscultatory hallmarks of this disorder, many patients have these signs without other diagnostic findings, consequently making it impossible to confirm the presence of MVP. Furthermore, the appearance of diagnostic echocardiographic abnormalities in patients with normal cardiac examinations implies that auscultation is not a sensitive marker of MVP. Both M-mode and two-dimensional echocardiography have technical limitations and the repeatability of interpretation of these tests is disappointingly low (80 to 90%). Because of these difficulties the angiographic-echocardiographic correlation is only fair. Nonetheless echocardiography has generally been accepted as the diagnostic modality of choice. Future technical improvements will likely enhance the diagnostic accuracy of this technique.

Echocardiography↗