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At least 865 records · Page 48Linked to original sources
PubMed1989

Late results of aortic valve replacement with Bjork Shiley prostheses: a comparison of standard aortic valve prosthesis with reversed mitral valve prosthesis implanted in aortic position.

Between 1976 and 1983, 435 patients underwent aortic valve replacement (AVR) with Bjork Shiley prostheses. Standard aortic Bjork Shiley prostheses (ABP) were used in 150 patients (Group I) and a reversed mitral Bjork Shiley prostheses in 285 (MBP in 250 and MBC in 35) patients (Group II). There was no significant difference in the number of the patients with valve calcification or the size of aortic root in the 2 groups. There was no significant difference in the early mortality in these two groups. The total follow up period in Group I was 912 years and 2130 years in Group II. The incidence of major aseptic prosthetic dehiscence and valve occlusion with tissue ingrowth were higher in Group I than in Group II. Reversed Bjork Shiley mitral valve prosthesis was successfully used in aortic position with reduced incidence of valve related complications.

Aortic Valve↗
PubMed2002

Five years of experience with mitral valve homografts.

INTRODUCTION: The main advantages of mitral homografts are preservation of the subvalvular apparatus and avoidance of life-long anticoagulation. In this communication, we will present our five-year experience using mitral homografts in mitral valve surgery. PATIENTS AND METHODS: Since 1996, 14 patients (mean age 46 +/- 8 years, range 27 - 65 years have had mitral homografts implanted. Thirteen patients had mitral valve replacement; the septal leaflet of the tricuspid valve was replaced in one case. The indications were mitral (n = 6) or tricuspid endocarditis (n = 1), mitral valve stenosis (n = 3), and combined mitral valve disease (n = 4). Complete mitral homografts were implanted in eight patients; partial homografts were used in six cases. Preoperatively, the dimensions of the left ventricle and the mitral valve were measured by transoesophageal echocardiography (TOE). The mean left ventricular ejection fraction was 56 +/- 9%, the mean end-diastolic diameter 58 +/- 6 mm. The technique described by Acar/Carpentier was adapted for implantation; a Carpentier ring was implanted in all cases for annular stabilization. The patients had anticoagulative therapy which was discontinued when stable sinus rhythm was present after three months postoperatively. Follow-up included clinical examination, ECG, and echocardiography, and was initiated six months postoperatively and continued on a yearly basis. The following parameters were determined by echocardiography--left atrial size, left ventricular end-diastolic and end-systolic diameter, pressure gradient across the mitral valve (c/w Doppler, Bernoulli's equation), and mitral regurgitation. RESULTS: All patients survived surgery; the mean operation-time was 281 +/- 37 minutes. Intraoperative TOE revealed a first degree insufficiency in 7 patients. Follow-up was completed in all patients, with a mean period of 30 months (6 - 60 months). Two patients had an acute endocarditis two years postoperatively, requiring repeat valve replacement with a mechanical prosthesis. An additional patient had to be reoperated due to chordal rupture three years postoperatively. All three patients had mitral valve stenosis as the initial indication for surgery and had received a complete homograft. In the remaining eleven patients, the morphological and functional state of the implanted grafts remained unchanged during follow-up. The freedom from valve-related events was 93% after one year, 86% after two years, and 79% after three years. At six-month follow-up, ECG and echocardiography revealed sinus rhythm and sufficient atrial contractions in 13 cases. At the last follow-up, the pressure gradients were 3.4 +/- 0.6 mmHg for complete homografts and 2.8 +/- 0.6 mmHg for partial homografts. In five cases, a mild insufficiency was documented, while six patients presented with competent grafts. CONCLUSIONS: Mitral homografts can be used with acceptable mid-term results in selected cases with good left ventricular function and only slightly dilated left ventricles. Partial mitral homografts represent an additional technique, especially for mitral valve repair in patients with acute endocarditis. The susceptibility to bacterial infections of a homograft makes strict prophylaxis against endocarditis mandatory.

Adult↗
PubMed1983

Comparative studies of mitral valves in rheumatic heart disease.

Mitral valve tissues from 195 patients with rheumatic heart disease removed at the time of cardiac surgery were studied by conventional histologic techniques. One hundred seven patients from a five-year period at All-India Institute for Medical Sciences in New Delhi were studied in conjunction with 88 patients undergoing cardiac surgery in Albuquerque during a similar period. In Indian patients a correlation was noted between degree of moderate or severe valvular calcification and extent of adjacent valvular mononuclear cellular infiltration often consisting of striking lymphocytic-plasma cell collections. Similar distinct correlations were not observed among the mitral valves from the Albuquerque patients. It is possible that mitral valve mononuclear cell infiltrates among Indian patients may reflect a chronic immune reaction influencing the natural course of rheumatic heart disease in this latter population.

Adolescent↗
PubMed1996

Left ventricular function following conventional mitral valve replacement in patients with chronic mitral regurgitation.

Conventional mitral valve replacement (MVR) for patients with chronic mitral regurgitation (MR) is usually associated with decrease in left ventricular (LV) ejection fraction (EF). This study investigated the effect of preoperative LV size on LV performance and examined loading conditions before and after conventional MVR. Echocardiographic study was performed on 13 and 9 patients with LV end-systolic dimension of less than 26 mm/m2 (group A) or greater than 26 mm/m2 (group B), respectively. Postoperatively, the LV end-diastolic dimension and EF decreased significantly in both groups. There was a decrease in end-systolic wall stress after MVR. Preoperative LV forward flow estimated by the normalized aortic peak velocity increased significantly in both groups after surgery. The decrease in EF after MVR is not the result of increased systolic loading, and LV performance may not decrease after conventional MVR. Preoperative echocardiographic evaluation can provide important prognostic information in patients with MR undergoing MVR.

Adolescent↗
PubMedDate not supplied

Use of three-dimensional sonomicrometry to study the motion of the mitral valve.

To develop an anatomically correct mitral valve prosthesis, one needs to study the dynamics of the mitral valve apparatus in vivo. The authors used three-dimensional (3D) sonomicrometry and custom visualization software to develop a system to study the mitral valve. Sixteen ultrasonic transducers each were implanted into the hearts of pigs under cardiopulmonary bypass. Four of these crystals were affixed to the base and apex of both papillary muscles, four were attached to the free edge of the anterior and posterior leaflets where the main chordae attach, six were placed around the mitral annulus, and two were affixed to the epicardial wall. The digital sonomicrometer system sequentially fired each transducer and listened for an ultrasound signal at the other 15. This process was repeated so that all 16 transducers were sequentially fired, and each cycle of 16 was repeated 200 times/sec. The matrix of distances obtained between all the combinations of pairs of the 16 transducers was converted to x, y, z coordinates, the shape of the mitral valve apparatus was reconstructed in 3D on a graphics computer, and the valve's motion was analyzed over several cardiac cycles. The authors conclude that mapping of the mitral valve apparatus in pigs by 3D sonomicrometry provides quantitative measurements that can aid in the design of a mitral valve prosthesis that closely replicates the anatomy and function of the natural valve.

Animals↗
PubMedDate not supplied

[Mitral valve prolapse. A review].

Primary mitral valve prolapse (MVP) or the disease known as MVP, consists of mixomatous degeneration of the mitral valve with systolic displacement of a portion or all of one or both mitral leaflets beyond mitral annulus into left atrium during systole, associated or not with mitral insufficiency. Prevalence in Mexican population is <2%. MVP behavior is benign unless associated with mitral insufficiency (MI, moderate-to-severe) or complications, or is associated with other syndromes. The major clinical feature of mitral valve prolapse syndrome is mid-to-late systolic clicks identified with auscultation of mitral valve. Echocardiography is usually employed for diagnosis and management. Two-dimensional echocardiography displays one or both leaflets prolapsing behind mitral annulus and into left atrium in systole. In the majority of cases, MVP is harmless and does not cause symptoms nor does it need to be treated. In a small number of cases, it can cause severe mitral regurgitation and needs surgical treatment. Complications derived from MVP must be treated independently. Secondary MVP also consist of displacement of one or both valves toward atrium, but this is due to pathologies such as rheumatic heart disease, ischemic heart disease, or others. In these situations, treatment will be that of the underlying diseases.

Humans↗
PubMed1986

[Doppler evaluation of porcine mitral valve dysfunction].

Seventy patients with bioprosthetic mitral valve were examined to study the applicability of the Doppler techniques including pulsed, continuous wave and color Doppler echocardiography in diagnosing and evaluating the severity of prosthetic valve dysfunction. The study population consisted of 70 patients who underwent mitral valve replacement (45 patients with Hancock valve, 13 with Angell-Shiley valve, 10 with Carpentier-Edwards valve). The dysfunctions were transvalvular regurgitation in 20 instances and paravalvular regurgitation in three, all of which were confirmed at surgery. A control group of 47 patients with the normally functioning porcine prosthetic mitral valve were also studied. Diastolic transmitral flow patterns were recorded from parasternal and apical approaches using color Doppler echocardiography, and the direction of the flow was definitely identified on the flow image. Transmitral flow signals spread from the mitral orifice to the mid-portion of the interventricular septum, and its direction was perpendicular toward the mitral ring in all cases. Flow velocity patterns in the left ventricle and atrium were recorded in the apical long-axis view of the left ventricle or apical four-chamber view using pulsed (high pulse repetition frequency) and continuous wave Doppler techniques. Two dynamic alterations in patients with the porcine mitral valve were evaluated from 1) the peak velocity and pressure half time (PHT) of transmitral flow in early diastole, and 2) the regurgitant jet in the left atrium indicating transvalvular or paravalvular regurgitation. The results were as follows: 1. Normally functioning porcine mitral valves were characterized by peak velocities (PV) less than or equal to 1.82 (mean +/- SD 1.44 +/- 0.27) m/sec and PHT less than or equal to 180 (mean +/- SD: 135 +/- 30) msec. In 23 patients with prosthetic valve dysfunction documented at surgery, peak velocity (mean +/- SD 2.23 +/- 0.19 m/sec) was significantly greater (p less than .001) than that of patients in the normally functioning prosthetic valves, and PHT ranged from 135 to 340 msec (mean +/- SD: 226 +/- 81 msec). 2. Among the 23 patients with porcine valve dysfunction, a harmonic striped pattern were recorded at the mitral valve levels in eight patients. All these patients had a musical murmur, and their peak velocity was more than 2.0 m/sec, but the PHT was less than 180 msec in seven patients. In these patients, valvular tears without calcification were confirmed at surgery.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2002

Mitral valve repair and the anterior leaflet.

Mitral valve repair with annuloplasty has become a widely accepted technique for correction of posterior leaflet mitral valve pathology. Advantages over mitral valve replacement include improved hemodynamic performance and improved ventricular function. Although repairs of the anterior leaflet met with less success initially, recent reports have emphasized the safety and effectiveness of chordal shortening, chordal transposition, and chordal replacement in treating disease of the anterior leaflet. Isolated annuloplasty and creation of double orifice mitral valves show promise for the treatment of mitral insufficiency in conjunction with heart failure and with other complex surgical procedures.

Humans↗
PubMed1994

Three-dimensional transesophageal echocardiography in the diagnosis of mitral valve prolapse.

Because the anulus of the mitral valve is nonplanar in systole, false-positive diagnosis of mitral valve prolapse may result from two-dimensional transthoracic echocardiography. Because of the superior image quality of TEE, we used the three-dimensional TEE technique to evaluate the mitral valve in both normal subjects and patients with mitral valve prolapse and with ruptured chordae tendineae. After a conventional TEE examination, sequential images of longitudinal views were obtained by probe rotation. The images at 5-degree intervals were stored in machine cine memory loop; the special temporal images were selected with ECG gating and videorecorded. During the examination, 6 to 8 images of the left heart were recorded for later off-line, three-dimensional reconstruction. A total of 42 subjects were studied: 32 normal, 9 with mitral valve prolapse, and 1 with ruptured chordae tendineae. In normal subjects, three-dimensional TEE showed nonplanarity of the entire mitral valve, which assumes a saddle shape. In mitral valve prolapse, either the anterior or posterior leaflet protruded into the left atrium like a spoon; when both leaflets are involved, they prolapse like two spoons. The anterior and posterior leaflets coapted poorly, and there was a seam between them. In ruptured chordae tendineae the tip of the mitral leaflet protruded during systole into the left atrium far from the coaptation point and was perpendicular to the body of the mitral valve and parallel to the anterior and posterior walls of the left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1982

[Evaluation of mitral valve, subvalvular structures and valvular flexibility in mitral stenosis by two-dimensional echocardiography].

UNLABELLED: In order to identify the determinants for surgical procedures in mitral stenosis, we evaluated two-dimensional echocardiographic findings of the mitral valve and subvalvular structures in 35 patients undergoing open mitral commissurotomy (OMC) or valve replacement (MVR). As indices of a degree of subvalvular shortening and valvular flexibility, the distance between the mitral ring and the tip of the anterior mitral leaflet was measured by the LV long-axis view by in both midsystole (S) and early diastole (D). As a possible major determinant for MVR, a degree of valvular calcification (C) was semi-quantatively scored according to the extent of abnormally strong echo density. In nine of 11 patients undergoing MVR, a main reason for selecting MVR was a marked thickening or shortening of subvalvular structures. In patients in whom OMC was feasible, the degree of improvement of the mitral valve area (delta MVA) was assessed by the pre- and post-operative mitral valve areas (MVA) measured on the LV short-axis view, which were averaged 0.15 and 1.38 cm2, respectively. RESULTS: The index C was significantly higher in cases with MVR than those with OMC (9.2 +/- 2.6 vs 4.7 +/- 2.3 points, p less than 0.001), although there was a significant overlap between these two groups and index C did not correlate with delta MVA in the OMC patients. Similarly, the value S was significantly smaller in patients undergoing MVR than those undergoing OMC (1.2 +/- 0.4 vs 0.7 +/- 0.2 cm, p less than 0.001), though S did not correlate with delta MVA. On the other hand, the index of valve flexibility D--S was smaller in patients undergoing MVR (0.5 +/- 0.3 vs 0.8 +/- 0.3 cm, p less than 0.05) and correlated well with delta MVA (delta MVA = 0.699 x (D--S)+0.007, R = 0.678, p less than 0.02) in patients undergoing OMC. Furthermore, in all patients undergoing OMC with D--S greater than or equal to 0.8 cm, delta MVA was above 0.5 cm2, contrasting with delta MVA of 0.5 cm2 or less in 6 of 7 patients with D--S less than 0.7 cm. Using these indices, surgical procedures were successfully predicted in another 7 prospectively studied patients and predicted delta MVA in 4 patients was quite comparable with actual delta MVA. It was concluded that measurements of S and D by two-dimensional echocardiography are useful, 1) to predict patients requiring MVR and 2) to predict patients with inadequate delta MVA in whom OMC is surgically feasible.

Adult↗
PubMed1996

Transversal trans-septal biatrial approach for mitral valve surgery.

A surgical approach to the mitral valve is very important to visualize all valvular and subvalvular structures. We have used a transversal trans-septal biatrial approach in some mitral procedures. From January 1994 to May 1994, 11 patients were operated on using this technique. Patient ages ranged from 28 to 74 years. Five cases (45.5%) were cardiac reoperations and six (54.5%) were first operations. Three case (27.3%) were mitral reconstructions, 3 (27.3%) were mitral replacement due to mechanical mitral valve thrombosis, 1 (9.1%) as a result of bioprosthetic mitral valve degeneration, 4 (36.4%) were mitral valve replacements for calcified mitral valve disease one case (9.1%) was tricuspid valve replacement due to severe tricuspid insufficiency. There were 4 case (36.4%) of tricuspid valvuloplasties besides the mitral procedures. There was no operative mortality, and all patients preserved their preoperative cardiac rhythm. No important bleeding or supra-ventricular arrhythmias were seen in any case. Aortic cross-clamping and extracorporeal circulation times were comparable with the traditional approach through the left atrial alone. So, we think that this is a very easy and useful technique to expose the mitral valve during some procedures above it, overall when the left atrium is small and total visualization of the mitral is not possible with the traditional approach through the left atrial alone.

Adult↗