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Prevalence of mitral valve prolapse in normal children.

Although echocardiography has become the standard noninvasive method of diagnosing mitral valve prolapse, the diagnostic criteria have been established without clearly defining the range of normal patterns for mitral valve closure. The current study reports the analysis of mitral valve closure patterns in 193 children (aged 5 days to 18 years) making scheduled visits for well child care who were screened by history and physical examination to exclude structural heart disease. Mitral valve systolic leaflet position was analyzed for the appearance of any portion of either leaflet superior to the plane of the anulus. Superior systolic motion was noted in 13% of the overall study group; this pattern was uncommon in infants but more frequent in older children, with a prevalence of 35% in the 10 to 18 year age group. There was no statistically significant difference between male and female children at any age. The prevalence of superior systolic motion decreased markedly if consideration was given to its presence in more than one echocardiographic view (1%) or to displacement of the coaptation point of the mitral valve leaflets (0.5%). Superior systolic motion occurs with such frequency in normal children as to call into question the reliability of this pattern of mitral valve closure as a standard for the diagnosis of mitral valve prolapse. More restrictive diagnostic criteria which consider the degree of leaflet displacement or its presence in multiple echocardiographic views may be necessary to identify those subjects whose mitral valve closure patterns truly fall outside the range of normal.

Adolescent↗

Repair of mitral valve billowing and prolapse (Barlow): the surgical technique.

Mitral valve repair in patients with mitral valve billowing and prolapse (Barlow) can be a demanding surgical procedure. A mitral valve repair method, which incorporates the complete resection of the middle scallop of the posterior leaflet, a sliding and folding plasty with the remaining lateral scallops combined with a triangular resection of the anterior leaflet and a ring-annuloplasty was developed, which maximizes predictable anatomic and physiologic efficacy of this repair and minimizes unpredictable results. A total of 37 consecutive patients underwent mitral repair with this method from 1996 to 1998, with consistently excellent results. Short-term follow-up information collected after 22.7 +/- 8.6 months showed one late death and 93.0% of all surviving patients in New York Heart Association functional class I or II. There were no late reoperations and no thromboembolic, bleeding, or other complications. No patient had recurrent mitral regurgitation.

Adult↗

Evaluation of the long-term results of mitral valve repair in 254 young patients with rheumatic mitral regurgitation.

BACKGROUND: Surgical valve repair for mitral regurgitation has significant advantages over valve replacement, but the durability of the technique varies according to the cause of mitral valve disease. In this study, we examined the long-term performance of this procedure in a young rheumatic population and also attempted to identify factors predicting a poor outcome. METHODS AND RESULTS: Between January 1981 and 1989, 308 patients underwent primary mitral valve repair for rheumatic mitral regurgitation at our institution. Forty-nine patients who failed to report after surgery and another 5 with discordant data were excluded from the analysis. Mitral regurgitation was pure in 182 patients (72%) and associated with mild commissural fusion in 72 patients (28%). Patient ages ranged from 6 to 52 years (mean, 18 +/- 9 years). A total of 243 patients (96%) were in New York Heart Association class III or IV before surgery, and 66 (26%) had atrial fibrillation. Mean follow-up period was 60 +/- 35 months (range, 1 to 132 months). Rheumatic activity was present clinically in 30% and macroscopically during surgery in 32%. Surgical techniques included insertion of a Carpentier ring (99%), chordal shortening (88%), leaflet resection (14%), chordal transposition (7%), and commissurotomy (28%). Operative mortality was 2.6%, late mortality was 15%, and the reoperation rate was 27%. At 5 years, 96.8% of the patients were free from thromboembolism, 97.7% were free from endocarditis, 74.9% were free from reoperation, 66% were free from valve failure, and 66.2% were free from major events. Multivariate analysis identified active rheumatic carditis as a significant predictor of reoperation, valve failure, and future events, while sinus rhythm and shorter bypass time at initial surgery were the only predictors of long-term survival. Patients with pure mitral regurgitation, sinus rhythm, and no active carditis at initial operation had the best overall 5-year results. Among the 148 survivors without reoperation, 142 (96%) were in New York Heart Association class I and II, and 107 (72%) were in sinus rhythm. Doppler echocardiographic studies showed absence of mitral regurgitation in 34 patients (23%), severe regurgitation in 23 (16%), and severe mitral stenosis in 6 (4%). CONCLUSIONS: Mitral valve repair in this young rheumatic population is associated with a high long-term morbidity. Presence of active rheumatic carditis has a significantly adverse effect on the success of mitral valve repair.

Actuarial Analysis↗

Mitral valve repair through combined left atrial and ventricular approach for congenital mitral stenosis.

A 3-year-old boy underwent mitral valve repair for congenital mitral stenosis through combined superior-septal atriotomy and apical left ventriculotomy. The operation was performed safely with excellent exposure of the subvalvular apparatus by the ventricular approach, while sufficient visualization of the valvular lesion was obtained by the atrial approach. Postoperative echocardiography demonstrated normal left-ventricular motion and no residual mitral stenosis.

Cardiac Surgical Procedures↗

Prevalence of mitral-valve prolapse in the Stickler syndrome.

An increased prevalence of mitral-valve prolapse occurs in several connective tissue dysplasias, including Marfan syndrome, Ehlers-Danlos syndrome, and pseudoxanthoma elasticum. We evaluated 57 patients diagnosed as having the Stickler syndrome for mitral-valve prolapse by auscultation and two-dimensional echocardiography. The diagnosis was made on the basis of craniofacial and musculoskeletal abnormalities, sensorineural hearing loss, eye defects, and a family history of Stickler syndrome. Twenty-six patients (45.6%) had mitral-valve prolapse, including 11 of 22 females (50.0%) and 15 of 35 males (42.9%). The age range of our study population was 4 to 60 years. Prevalence of mitral-valve prolapse did not increase with age. Nine patients (34.6% of those with mitral-valve prolapse) had the click-murmur syndrome; only one of them was symptomatic. Because of the growing list of complications associated with mitral-valve prolapse, all patients with Stickler syndrome should be evaluated by auscultation, electrocardiogram, and echocardiography. Those with mitral-valve prolapse should be advised to have periodic follow-up and to instruct physicians caring for them of their need for antibiotic prophylaxis with certain surgical procedures.

Adolescent↗

Minimally invasive port access versus conventional mitral valve surgery: prospective randomized study.

BACKGROUND: We compared the port access mitral valve surgery with the conventional procedure through median sternotomy in a prospective randomized study. METHODS: Forty elective patients with mitral valve disease were prospectively randomized to undergo minimally invasive (group I) or conventional (group II) mitral valve operation. The patients of group I had limited access through right small anterior thoracotomy and a femorofemoral cardiopulmonary bypass system using the endoclamp technique. To assess the efficiency and safety of the procedure, intraoperative and postoperative clinical data and markers of myocardial, cerebral, and lower limb ischemia were collected. Pulmonary function tests were performed to compare the preservation of pulmonary function. Neuropsychological tests were conducted for quantification of neurological and cognitive disorders. RESULTS: Mitral valve reconstructions were performed in 28 patients (70%) in both groups. Intraoperative procedure-associated problems were experienced in 9 patients (45%) in group I, and 6 of them (30%) had to be converted to direct transthoracic aortic clamping. Markers of myocardial and cerebral damage as well as pulmonary and neuropsychological tests did not show statistically significant difference between groups. CONCLUSIONS: The minimally invasive port access technique for mitral valve surgery can be done with similar clinical safety as procedures through median sternotomy. The problems with endoclamping have forced us to change our practice to the more simple and economic transthoracic aortic clamping technique.

Cardiopulmonary Bypass↗

Mitral valve area by colour flow imaging.

Colour Doppler assessment of mitral valve area was carried out in 78 patients with mitral stenosis. The mitral valve area was calculated using the equation pi/4 (a x b), where a = color jet width at the mitral valve in the apical long axis view and b = width of the color jet in a 90 degree rotated view from the apex. The valve area obtained from the color jet was compared with the valve area obtained from the pressure half time. It was found that there was a good correlation between these two measurements (r = 0.82; p < 0.001) while 2D echo derived mitral valve area correlated at an r value of 0.80 (p < 0.001). It is concluded that the new method can be used as an adjunct to currently available methods to assess the severity of mitral stenosis.

Adolescent↗

Clinical experiences with minimally invasive mitral valve surgery using a simplified Port Access technique.

OBJECTIVE: Using the initial experiences with the Port-Access technique for the treatment of mitral valve disease some changes were made thus resulting in more simple and faster procedures. METHODS: Twenty-nine patients (13 male, 16 female, aged 30 to 75 years, median 62.5 +/- 11.0 years) underwent minimally invasive mitral valve surgery between May 1996 and December 1997. The underlying diseases were: mitral valve insufficiency (n = 16), mitral valve stenosis (n = 7) and combined mitral valve disease (n = 6). Through a small right thoracotomy (5-7 cm) access to the pericardium and the heart was gained. Cardiopulmonary bypass was instituted through femoral cannulation and an intraaortic balloon-catheter was introduced for aortic occlusion, aortic root venting and delivery of cold crystalloid cardioplegia. Mitral valve repair (five patients) or replacement (24 patients) was performed. RESULTS: There was no death during the whole follow-up period. There was no perivalvular leak and only minor residual mitral valve regurgitation was observed on intraoperative or postoperative (3 months) transesophageal echocardiography in three patients. There was no postoperative study-related complication. Time of ventilation and intensive care unit were comparable with the data of patients undergoing conventional mitral valve surgery but hospital stay was shorter in the last 10 consecutive cases. CONCLUSIONS: This simplified technique of mitral valve surgery combines the advantage of less invasive operative and good cosmetic results with the safety of conventional mitral valve surgery. At our institution this technique presents in well selected patients suffering from mitral valve disease the procedure of choice.

Cardiac Surgical Procedures↗

Long-term follow-up after mitral valve reconstruction: incidence of postoperative left ventricular outflow obstruction.

Reconstructive surgery of the mitral valve has been an alternative to mitral valve replacement in patients with mitral regurgitation. Previously, we reported on postoperative left ventricular outflow tract obstruction associated with systolic anterior motion of the anterior mitral leaflet. The current study was designed to evaluate the incidence of this complication and the long-term results of mitral valve reconstructive surgery. Sixty-five patients, aged 19 to 78 years, had mitral valve reconstructive surgery. Two patients died perioperatively, and three died late after surgery. The 60 surviving patients were studied by M mode, two-dimensional, and Doppler echocardiography 1 to 55 months postoperatively (mean 21). Fifty patients had no evidence of postoperative mitral regurgitation, two patients had moderate mitral regurgitation, three patients had mild mitral regurgitation, and five patients had trace mitral regurgitation. No significant mitral stenosis was detected in any patient postoperatively. After surgery, the diameter of the left ventricular outflow tract was significantly smaller than that before surgery. The echocardiograms of six patients showed abnormal systolic anterior motion of the anterior mitral leaflet that was not observed preoperatively. Doppler echocardiography demonstrated pressure gradients across the left ventricular outflow tract between 10 and 64 mm Hg. Inhalation of amyl nitrite increased these gradients. An additional patient who had systolic anterior motion but no gradient developed a 36 mm Hg gradient after inhalation of amyl nitrite. The remaining patients had no gradient induced by amyl nitrite. Abnormal systolic anterior motion of the anterior mitral leaflet may be surgically induced by changes in left ventricular geometry and the size of the left ventricular outflow tract during systole.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Wavelength and conduction inhomogeneity in each atrium in patients with isolated mitral valve disease and atrial fibrillation.

INTRODUCTION: Patients with mitral valve disease frequently have atrial fibrillation (AF), and the left atrium is presumed to be the primary atrium that develops AF. However, it is still not clear whether the electrophysiologic abnormalities responsible for AF are confined to the left atrium in this subset of patients. METHODS AND RESULTS: To examine the AF vulnerability of each atrium, we measured the wavelength and inhomogeneity of the conduction at the lateral right atrium, lateral left atrium, and Bachmann's bundle after defibrillation of AF in seven patients undergoing the maze procedure and mitral valve surgery for AF and isolated mitral valve disease, respectively (AF group). The data were compared with five coronary surgery patients in sinus rhythm (SR group). The wavelength in the AF group was significantly shorter (P < 0.05) than in the SR group not only at the lateral left atrium (225 +/- 62 vs 285 +/- 36 mm) but also at the lateral right atrium (214 +/- 54 vs 254 +/- 34 mm). The variation coefficient of the local maximum activation phase difference in the AF group (1.9 +/- 0.8 at the right atrium, 2.1 +/- 0.8 at the lateral left atrium, and 2.0 +/- 0.6 at Bachmann's bundle) was significantly greater (P < 0.05) than in the SR group at all atrial regions. CONCLUSION: AF vulnerability was not confined to the left atrium immediately after defibrillation in AF patients with isolated mitral valve disease. Electrical remodeling resulting from perpetuation of AF, pathological changes extending to the right atrium, geometric changes caused by the atrial interactions occurring across the interatrial septum, or a combination of these may explain the results.

Atrial Fibrillation↗

Combined aortic and mitral balloon valvuloplasty in patients with critical aortic and mitral valve stenosis: results in six cases.

Six patients with severe combined aortic and mitral valve stenosis underwent double valve balloon dilation as an alternative to surgical valve replacement. Cardiac catheterization in all patients before valve dilation revealed heavily calcified aortic and mitral valves with severe stenosis and minimal regurgitation. Balloon aortic valvuloplasty was performed in each patient with a 20 mm balloon dilation catheter passed retrograde through the aortic valve whereas mitral valvuloplasty was performed transseptally with either a single or double balloon technique. After dilation, the mean aortic and mitral gradients decreased in all patients, with the area of the aortic and the mitral valve increasing from 0.5 +/- 0.3 to 0.9 +/- 0.3 cm2 and from 0.7 +/- 0.1 to 1.5 +/- 0.7 cm2, respectively. The procedures were well tolerated, with no embolic events and no significant increase in valvular regurgitation, and resulted in a reduction in symptoms of dyspnea on exertion and weakness in all patients that has persisted for an average of 5.7 months of follow-up in five of the six patients. It is concluded that combined dilation of stenotic aortic and mitral valves can be accomplished percutaneously and may be considered for patients with combined valvular stenosis who refuse or are deferred from surgical intervention.

Aged↗

Ischemic mitral valve repair: correlations between the mechanisms of mitral regurgitation and left ventricular function prior to and following surgery.

OBJECTIVE: To define the mechanisms of ischemic mitral regurgitation (MR) and its correlation with left ventricular (LV) function prior to and 1 year following mitral valve (MV) repair. DESIGN: Fifty-three patients (pts) underwent echocardiographic evaluation of the MR mechanism according to Carpentier's classification; quantification of MR and LV function. RESULTS: Forty-one, 5% of pts had Type I (annulus dilation), 20, 5% had Type II (commissural prolapse) and 38% had Type IIIb MR (predominant posterior leaflet restriction). Preoperative LV function was slightly better preserved in pts with Type II and IIIb MR. Despite similar MV repair efficiency intraoperatively, after 1 year Type I MR progressed vs the remaining types. LV function, including dimensions, ejection fraction and pulmonary artery pressure had a tendency to worsen in pts with Type I and markedly improved in Type II and IIIb MR. CONCLUSIONS: Ischemic MR of Type I is associated with more marked LV dysfunction preoperatively, its further deterioration and MR progression after MV repair. Type II and IIIb MR correlates with better preserved LV function preoperatively and its incremental improvement late after surgery.

Aged↗

Huge left atrial thrombus and valve degeneration in a patient with a bioprosthetic, porcine, mitral valve.

A 43 year old man with a Hancock porcine bioprosthetic valve in the mitral position developed a huge thrombus filling the entire left atrium and chronic degeneration of the bioprosthetic mitral valve. The effective valve orifice was less than 2 mm. These severe findings leading to the patient's death remained undetected while he was alive. This case illustrates the great need for a serial phonoechocardiographic studies in all patients with prosthetic valves.

Adult↗

Mitral valve replacement with ball valve prostheses.

Our experience with ball valve replacement of the mitral valve during the past decade is presented in terms that allow comparison with other techniques. The use of such prostheses is characterized by ease of implantation, with an overall operative mortality of 11 per cent for isolated mitral replacement and 13 per cent for multiple valve replacement. The operative mortality for isolated mitral valve replacement during 1969 and thus far in 1970 has been nil. The late mortality was 13 per cent for isolated mitral replacement and 20 per cent for multiple valve replacement. Forty-three per cent of the total late deaths were clearly unrelated to the prosthetic device itself. The overall incidence of late infection and leak is less than 1 per cent and the immediate haemodynamic benefit is not altered by loss of structural integrity of the prosthesis. The most serious problem after mitral valve replacement with the ball valve prosthesis is that of thromboembolic complications. While thrombotic stenosis of the prosthesis is a rarity, embolic episodes, usually cerebral in type, have been noted in 63 per cent of the patients surviving mitral valve replacement with the earliest model ball valve from August 1960 to February 1966. Improvements in valve design have resulted in a remarkable decrease in this incidence as examined by actuarial techniques and taking into account the duration of follow-up. The extension of the cloth sewing margins to the orifice of the valve while maintaining a metallic orifice and metallic cage (Model 6120) resulted in a drop of the thromboembolic rate to 17 per cent from April 1965 to April 1969. The development of the totally cloth-covered prosthesis has further improved these results, with only one thromboembolic complication after isolated mitral valve replacement with the Model 6310 valve in a series of 66 consecutive patients. In clinical practice this has resulted in the avoidance of the use of anticoagulant therapy in patients in whom for a variety of reasons this carries an increased hazard. With further follow-up it may be possible to discontinue the routine use of anticoagulants.

Adolescent↗

In vitro dynamic strain behavior of the mitral valve posterior leaflet.

Knowledge of mitral valve (MV) mechanics is essential for the understanding of normal MV function, and the design and evaluation of new surgical repair procedures. In the present study, we extended our investigation of MV dynamic strain behavior to quantify the dynamic strain on the central region of the posterior leaflet. Native porcine MVs were mounted in an in-vitro physiologic flow loop. The papillary muscle (PM) positions were set to the normal, taut, and slack states to simulate physiological and pathological PM positions. Leaflet deformation was measured by tracking the displacements of 16 small markers placed in the central region of the posterior leaflet. Local leaflet tissue strain and strain rates were calculated from the measured displacements under dynamic loading conditions. A total of 18 mitral valves were studied. Our findings indicated the following: (1) There was a rapid rise in posterior leaflet strain during valve closure followed by a plateau where no additional strain (i.e., no creep) occurred. (2) The strain field was highly anisotropic with larger stretches and stretch rates in the radial direction. There were negligible stretches, or even compression (stretch < 1) in the circumferential direction at the beginning of valve closure. (3) The areal strain curves were similar to the stretches in the trends. The posterior leaflet showed no significant differences in either peak stretches or stretch rates during valve closure between the normal, taut, and slack PM positions. (4) As compared with the anterior leaflet, the posterior leaflet demonstrated overall lower stretch rates in the normal PM position. However, the slack and taut PM positions did not demonstrate the significant difference in the stretch rates and areal strain rates between the posterior leaflet and the anterior leaflet. The MV posterior leaflet exhibited pronounced mechanically anisotropic behavior Loading rates of the MV posterior leaflet were very high. The PM positions influenced neither peak stretch nor stretch rates in the central area of the posterior leaflet. The stretch rates and areal strain rates were significantly lower in the posterior leaflet than those measured in the anterior leaflet in the normal PM position. However, the slack and taut PM positions did not demonstrate the significant differences between the posterior leaflet and the anterior leaflet. We conclude that PM positions may influence the posterior strain in a different way as compared to the anterior leaflet.

Animals↗

Cleft in the anterior and posterior leaflet of the mitral valve: a rare anomaly.

A rare entity that causes congenital mitral regurgitation is an isolated cleft mitral valve. The cleft in the mitral valve can be seen in either the anterior or posterior leaflet of the valve. We present a unique case of an individual with a history of congenital mitral regurgitation caused by a cleft in both the anterior and posterior leaflets of the mitral valve.

Adult↗

Mitral valve replacement in a patient with an extensively calcified mitral anulus: report of a case.

We report herein the case of a patient with chronic renal failure in whom mitral valve stenosis with extensive mitral anular calcification involving the entire anulus and leaflets was successfully treated surgically. Excision of both leaflets and partial resection of the anular calcification enabled the insertion of a 23-mm St. Jude Medical prosthetic valve. The technical difficulties involved with inserting the appropriate-sized prosthetic valve in a narrowed mitral anulus with heavy calcification are discussed following this case report.

Calcinosis↗