Severe mitral regurgitation due to mitral valve prolapse: risk factors for development, progression, and need for mitral valve surgery

Patients with mitral valve prolapse (MVP) may develop severe mitral regurgitation (MR) and require valve surgery. Preliminary data suggest that high body weight and blood pressure might add to the irreversible factors of older age and male gender in increasing risk of these complications. Fifty-four patients with severe MR due to MVP were compared with 117 control subjects with uncomplicated MVP to elucidate factors independently associated with severe MR: the need for valve surgery and the cumulative risk of requiring mitral valve surgery. Patients with severe MR were older (p<0.00005), more overweight (p = 0.002), had higher systolic (p = 0.0003) and diastolic (p = 0.007) blood pressures, and were more likely to have hypertension (p = 0.0001) and to be men (p<0.001). In both groups, men had higher blood pressure and relative body weight than women. In multivariate analysis, older age was most strongly associated with MR; higher body mass index, hypertension, and gender were independent predictors of severe MR in analyses that excluded age. Among the 54 patients with severe MR, the 32 (59%) who underwent mitral valve surgery during 11 years of follow-up were older, more overweight, and more likely to be hypertensive than those not requiring surgery. Among patients undergoing mitral valve surgery in 3 centers, mitral prolapse was the etiology in 25%, 67% of whom were men. Using these data and national statistics, we estimate that the gender-specific cumulative risk for requiring valvular surgery for severe MR in subjects with MVP is 0.8% in women and 2.6% in men before age 65, and 1.4% and 5.5% by age 75. Thus, subjects with MVP who are older, more overweight, and hypertensive are at greater risk for severe MR and valve surgery. Higher blood pressure and relative weight in men with MVP appear to contribute to the gender difference in risk for severe MR.     

Left atrial volumes, function and work before and after mitral valve repair in chronic mitral regurgitation

BACKGROUND AND AIM OF THE STUDY: Despite the effect of mitral valve repair in left ventricular (LV) function having been extensively studied, investigations of left atrial (LA) performance indices are minimal. This prospective study was undertaken to analyze LA volumes, function and work in patients with chronic mitral valve regurgitation (MR) who underwent mitral valve repair; the analyses were conducted both before and six months after surgery. METHODS: Twenty patients (15 males, five females; mean age 51.4 +/- 12.5 years) with severe MR (grade IV) due to floppy mitral valve/mitral valve prolapse (FMV/MVP; anterior, posterior or both) underwent mitral valve repair. LA volumes, maximal at mitral valve opening (LAmax); minimal at valve closure (LAmin); and at onset of atrial systole (P-wave on ECG, LAP); and transmitral Doppler A-wave velocity were measured before and six months after surgery. LA stroke volume (LASV) = LAP - LAmin; LA ejection fraction (LAEF) = LASV/LAP; LA kinetic energy (LAKE) = 1/2 x LASV x 1.06 (specific gravity of blood) x A2 (dyne x cm x 10(3)); LA and LV dimensions and functions were assessed at the same time. RESULTS: NYHA functional class was improved postoperatively by at least one grade. LV systolic and diastolic dimensions were reduced significantly in all patients (p <0.001). LA volumes (LAmax, LAmin and LAP) were decreased significantly in all patients (p <0.001); LASV remained unchanged. LAEF and LAKE were increased significantly (both p <0.001). The A-wave was also increased (p <0.001). CONCLUSION: Increased LA work (LAKE) after mitral valve repair, despite a decrease in LA volumes, suggests that LA muscle dysfunction was present before surgery. LA involvement may precede LV involvement. The determination of LA performance and work will help to optimize the timing of surgery in patients with FMV/MVP and MVR.     

Evidence for progression from mild to severe mitral regurgitation in mitral valve prolapse

Little information is available concerning the progression of mild to severe mitral regurgitation (MR) in patients with mitral valve prolapse (MVP). This study reports 86 patients, average age 60 years, who presented with cardiac symptoms, precordial systolic murmur, severe MR and a high incidence of MVP on echocardiography (57 of 75 [75%] ) and left ventriculography (61 of 84 [73%] ). Seventy-five surgically excised mitral valves appeared grossly enlarged and floppy. Histologic studies showed extensive myxomatous changes throughout the leaflets and chordae. Eighty patients had had precordial murmurs first described at average age 34 years, but the average age at which symptoms of cardiac dysfunction appeared was 59. However, once symptoms developed, mitral valve surgery was required within 1 year in 67 of 76 patients who had undergone surgery. Atrial fibrillation, present in 48 of 86 patients (56%), or ruptured chordae tendineae, present in 39 of 76 patients (51%), may have contributed to this rapid progression and deterioration. Additionally, 13 patients had a remote history of documented infective endocarditis. Twenty-eight patients had at least 1 type of serial clinical evaluation that indicated progressive MR in all 28 patients on the basis of changing auscultatory findings (24 of 26), progressive radiographic cardiomegaly (24 of 25), echocardiographic left atrial enlargement (4.3 to 5 cm in 11 patients) and angiographically worsening MR (14 of 15). Twenty-four of these patients had evidence of MVP on at least 1 of their initial studies. Thus, mild MR due to MVP and myxomatous mitral valves is a progressive disease in some patients with MVP.     

Progression of mitral regurgitation in patients with mitral valve prolapse

Mitral valve prolapse (MVP) is a very common clinical entity which is frequently associated with mild mitral regurgitation (MR) and which most commonly becomes clinically manifest in the third and fourth decades of life. Severe MR associated with MVP, occurs much less frequently and is most commonly seen in patients above the age of 50 years. Relatively little information is available regarding the progression of mild to severe MR in patients with MVP. This report reviews a recent study which investigated the progression from mild to severe MR in patients with MVP. The study included 86 patients, average age 60 years, who presented with cardiac symptoms and severe MR. A high incidence of MVP was seen on echocardiograms (57 of 75 [75%]) and on left ventriculography (61 of 84 [73%]). Mitral valve replacement was performed in 75 patients. Pathologically all valves appeared grossly enlarged, severely floppy and had extensive myxomatous changes with collagen dissolution. 80 patients had a pre-existing heart murmur first detected at average age 34. Patients remained asymptomatic for an average of 25 years at which time clinical symptoms first appeared. After symptoms developed mitral valve surgery was necessary in most patients within one year. This rapid deterioration could partially be attributed to ruptured chordae in 39 of 76 patients (51%) or atrial fibrillation in 48 of 86 patients (56%). 28 patients had one or more serial clinical evaluations including auscultation, chest x-ray, echocardiography, and cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Results of valve reconstruction for mitral regurgitation secondary to mitral valve prolapse

Mitral valve prolapse (MVP), often the result of myxomatous degeneration of the mitral valve, is the most commonly known pathologic entity leading to pure mitral regurgitation (MR). Reconstruction of the mitral valve rather than replacement is particularly applicable to this pathologic defect, but is not often used in the U.S. Experience with reconstruction of the mitral valve for MR secondary to MVP during the period January 1970 to January 1984 was reviewed. A total of 479 patients with mitral valve disease underwent operation during this period, 82 (17%) of whom had MR secondary to MVP. Thirty-one patients (6%) had valve reconstruction by a technique of leaflet plication and posteromedial anuloplasty. Eleven of these patients had associated cardiac disease requiring correction: 2 requiring aortic valve replacement and 9 requiring coronary artery bypass grafting procedures. One hospital death (3%) and 6 late deaths (19%) occurred, of which only 3 were related to cardiac factors. Major complications included recurrent MR in 5 patients and cerebral embolus in 1 patient. The adjusted 5-year survival rate was 89 +/- 6 (mean +/- standard error of the mean), and the overall survival rate of patients free of cardiac-related complications was 73 +/- 9%. Thus, reconstruction of the mitral valve is a highly effective surgical approach to the management of symptomatic patients with MR secondary to MVP, and its use is favored over replacement in the management of these patients.     

Feasibility of myxomatous mitral valve repair using direct leaflet and chordal radiofrequency ablation

Objective: Minimally invasive repair of mitral valve prolapse (MVP) causing severe mitral regurgitation (MR) should reduce MR and have chronic durability. Our ex vivo, acute in vivo, and chronic in vivo studies suggest that direct application of radiofrequency ablation (RFA) to mitral leaflets and chordae can effect these repair goals to decrease MR. Methods: A total of seven canines were studied to assess the effects of RFA on mitral valve structure and function. RFA was applied ex vivo (n = 1), acutely in vivo using a right lateral thoracotomy and cardiopulmonary bypass (n = 3), and chronically in vivo using percutaneous access to the heart (n = 3). RFA was applied to the mitral valve and its associated chordae. Mitral valve structure and function (in vivo preparations) were then assessed. Results: Ex vivo application of RFA resulted in qualitative reduction in mitral leaflet surface area and chordal length. Acute in vivo application of RFA to canines found to have MVP causing severe MR demonstrated a 43.7–60.7% statistically significant (P = 0.039) reduction in postablation MR. Chronic, in vivo, percutaneous application of RFA was found to be feasible and the engendered alterations durable. Conclusion: These data suggest that myxomatous mitral valve repair using radiofrequency energy delivered via catheter is feasible.     

Mitral regurgitation in mitral valve prolapse: its mechanisms and time course

To clarify the mechanisms and time course of mitral regurgitation (MR) in mitral valve prolapse (MVP), the relationship between the timing of MR flow patterns on pulsed Doppler echocardiography and phase of mitral valve prolapse on two-dimensional echocardiography was investigated. 1. Thirty-seven patients with MVP were followed by pulsed Doppler echocardiography for one to six years with an average of 2.5 years. At the initial examination, the patients were classified in five subsets on the basis of the presence or timing of MR: 10 without MR, five with early systolic MR, one with mid-systolic MR, 15 with late systolic MR and six with pansystolic MR. During the follow-up period, the timing of MR did not change in 21 patients (three with no MR, five with early systolic MR, seven with late systolic MR and six with pansystolic MR). Various changes were observed in 16 patients, i.e., developments of late systolic MR from no MR in four, of pansystolic from no MR in three, from late systolic MR in five and from mid-systolic MR in one, and disappearing late systolic MR in three. 2. Mitral annular diameter and the prolapsing phase of 118 patients with MVP (44 without MR, eight with early systolic MR, 30 with late systolic MR and 36 with pansystolic MR) were examined by long-axis two-dimensional echocardiography. The mitral annular diameter in patients with early systolic MR was significantly less than that of other MR groups, and the diameter in patients with pansystolic MR was markedly increased. The timing of MR was determined according to the prolapsing phase and the grade of the prolapse and the systolic size of the mitral annulus. Six of the eight patients with early systolic MR first had early systolic prolapse of either mitral leaflet, and then the regurgitant gap of the mitral valve orifice was plugged by the prolapsing leaflet and/or the narrowed mitral annulus during mid-to-late systole. In 18 of the 30 patients with late systolic MR, the grade of prolapse of the mitral valve during mid-to-late systole was more severe, compared with that of early systole. The results of the present study indicated that the occurrence of MR in MVP is various in timing (early, mid-, late or pansystole) and shows various changes the during follow-up study, and that pulsed Doppler echocardiography allows phase analysis of MR in MVP.     

Frequency of atrial fibrillation in patients having mitral valve repair or replacement for pure mitral regurgitation secondary to mitral valve prolapse

Relatively little attention has been paid to the frequency of atrial fibrillation (AF) in patients with mitral regurgitation (MR) secondary to mitral valve prolapse (MVP). We reviewed clinical, electrocardiographic, echocardiographic, hemodynamic, and angiographic findings in 246 patients aged 21 to 84 years (mean 61) (66% men) who had mitral valve repair or replacement for MR secondary to MVP. Immediately before the mitral operation by electrocardiogram, only 37 patients (15%) had AF and the other 209 patients were in sinus rhythm. Of the latter, 32 had had a history of AF that had reverted to sinus rhythm spontaneously or with antiarrhythmic therapy. Thus, a total of 69 patients (28%) had AF at some time. In conclusion, the frequency of AF in patients with MR secondary to MVP and sick enough to warrant a mitral valve operation have a relatively low frequency of AF (persistent in 15%, paroxysmal in another 13%), percentages considerably lower than that seen in patients with mitral stenosis just before a mitral commissurotomy or replacement.     

Multiplanar visualization in 3D transthoracic echocardiography for precise delineation of mitral valve pathology

A novel multiplanar reformatting (MPR) technique in three-dimensional transthoracic echocardiography (3D TTE) was used to precisely localize the prolapsed lateral segment of posterior mitral valve leaflet in a patient symptomatic with mitral valve prolapse (MVP) and moderate mitral regurgitation (MR) before undergoing mitral valve repair surgery. Transesophageal echocardiography was avoided based on the findings of this new technique by 3D TTE. It was noninvasive, quick, reproducible and reliable. Also, it did not need the time-consuming reconstruction of multiple cardiac images. Mitral valve repair surgery was subsequently performed based on the MPR findings and corroborated the findings from the MPR examination.     

经导管二尖瓣修复治疗二尖瓣反流所致心力衰竭的进展与展望

二尖瓣关闭不全主要是由于瓣膜的异常所导致的原发性或退化性的二尖瓣反流（mitral valve regurgitation,MR）,也可由继发性心肌病变引起功能性、继发性MR。药物治疗可以缓解相应症状,但却无法阻止病程进展。目前,尽管有明确的指南建议对伴有左心功能不全症状和体征的中至重度（NYHA分级超过Ⅲ级）MR患者进行手术,但由于种种客观与主观的原因大多数严重MR患者仍没有接受手术。随着经导管二尖瓣介入手术修复治疗的蓬勃发展,目前的经导管二尖瓣修复治疗的理念主要来源于外科修复技术,分别以缘对缘、人工腱索修复、人工瓣环成形等方式为代表,有不同种类的器械进入临床,取得了良好的效果。经导管介入治疗MR为二尖瓣手术高危患者提供了新的选择。本文将综述手术治疗MR所致心力衰竭的新进展。     

Floppy mitral valve/mitral valve prolapse and genetics

Mitral valve prolapse (MVP) is a defect in the mitral valve where a redundancy of valve tissue is associated with a variety of clinical expressions, ranging from an isolated mild bulging of the mitral valve to a severe prolapse of the mitral valve with extensive mitral regurgitation. As the natural history and complications of MVP are not always benign, it seems essential to strive for the proper management of these patients. The identification of functionally related genes could provide helpful clues and increase the present understanding of the pathogenesis of MVP, with the ultimate goal of developing targeted therapies. The genetics of MVP can be divided into two parts: (i) Genetics in floppy mitral valve/MVP; and (ii) genetics in heritable connective tissue disorders (Marfan syndrome, polycystic kidney, etc.) associated with floppy mitral valve. Herein, the known genetic aspects of MVP are described, according to the above-mentioned scheme.     

Percutaneous edge-to-edge mitral valve repair

In the past few years, a myriad of technologies have been developed for percutaneous repair of the mitral valve for patients with severe mitral regurgitation (MR) and at high risk for traditional open-heart mitral valve surgery. Among them, MitraClip has emerged as the only clinically safe and effective method for percutaneous mitral valve repair. This device mimics the surgical edge-to-edge mitral valve repair initially described by Dr. Alfieri. In this article, we review the current clinical evidence on the use of the MitraClip—from the randomized control trial EVEREST II to the information derived from expert high-volume centers.     

Stentless mitral valve implantation in comparison to conventional mitral valve repair or replacement at five years

OBJECTIVE: A chordally supported stentless mitral valve (SMV) may be a suitable prosthesis for patients with severe degenerative mitral valve disease. We analyzed the five-year results and compared them with results after conventional mitral valve repair or replacement. METHODS: 155 patients, operated on since August 1997, were evaluated. 53 patients (ages, 68 +/- 8 years, 37 female, valve repair not feasible) received a SMV (Quattro), 51 patients (69 +/- 9 years, 32 female) had mitral valve repair (MVR) and 51 patients (66 +/- 9 years, 32 female) had a conventional mitral valve replacement (MVP). There were no significant differences with respect to preoperative NYHA functional class, left ventricular ejection fraction, cardiac index and surgical risk, according to the EuroSCORE. Mean follow-up is 64 +/- 18 (21-89) months. RESULTS: Surgery was performed using a median sternotomy (32 [SMV]/20 [MVR]/34 [MVP]) or a lateral mini-thoracotomy 21/31/17 approach. The SMV was safely attached to the papillary muscles. In-hospital mortality was 1, 2 and 4 respectively; re-operation was required in 6, 2 and 3 patients. Five-year survival rate was 80.6 +/- 4.4 % (SMV), 80.2 +/- 5.6 % (CMV) and 82.6 +/- 5.6 % (MVP), p = n.s. After hospital discharge, there was no significant difference in mortality in comparison to an age-matched control population. Echocardiography revealed acceptable SMV hemodynamics with preservation of left ventricular function. CONCLUSION: Midterm results after SMV implantation are comparable to conventional approaches. Complete preservation of the annulo-ventricular continuity is advantageous and close to physiologic hemodynamics can be achieved. Long term follow-up is required.     

Severe intravascular hemolysis following mitral valve repair

We report two cases of severe intravascular hemolysis (IVH) following mitral valve repair using a Cosgrove-Edwards ring. In both cases, the degree of mitral regurgitation (MR) seen postoperatively worsened significantly compared to intraoperative transesophageal echocardiogram. Both patients required reoperation with mitral valve replacement with immediate resolution of the hemolysis. We hypothesize that the mitral regurgitation in the setting of an inadequate mitral valve repair is responsible for the hemolysis and propose various mechanisms to explain this pathophysiology. Although IVH remains a rare complication following mitral valve repair, possible screening recommendations should be considered for early detection and treatment given the growing number of mitral valve repairs being performed.     

Frequency and significance of M-mode echocardiographic evidence of mitral valve prolapse in clinically isolated pure mitral regurgitation: analysis of 65 patients having mitral valve replacement

To assess the reliability of M-mode echocardiographic patterns of mitral valve prolapse (MVP) (echo MVP) in detection of morphologic evidence of MVP (morphologic MVP), operatively excised mitral valves and corresponding M-mode echocardiograms from 65 patients with chronic, severe, isolated, pure mitral regurgitation (MR) were studied. Of the 65 patients, 45 (69%) had echo MVP (either holosystolic or mid-to-late systolic prolapse patterns on preoperative M-mode echograms) and 42 (93%) of them had morphologic MVP; of the 3 without morphologic MVP, 2 had ruptured chordae tendineae from infective endocarditis and 1 had papillary muscle dysfunction from atherosclerotic coronary heart disease. Of the 20 patients without echo MVP, 14 (70%) had no morphologic MVP (9 had papillary muscle dysfunction from coronary heart disease, 4 had infective endocarditis on previous normal valves and 1 had rheumatic heart disease). Of the 48 patients with morphologic MVP, 42 (88%) had echo MVP and most had considerably dilated mitral anulae; the other 6 had ruptured chordae tendineae with less degrees of anular dilatation. Of the 17 patients without morphologic MVP, 3 had echo MVP (coronary artery disease in 1 and infective endocarditis on a previous normal valve in 2); of the 14 with neither echo nor morphologic MVP, 9 had papillary muscle dysfunction from coronary artery disease, 4 had infective endocarditis on previously normal valves and 1 had rheumatic heart disease. The patients with very dilated mitral anuli and leaflet areas generally had holosystolic (hammocking) patterns on echo; the patients with small anuli and leaflet areas usually had mid-to-late systolic (buckling) prolapse patterns.     

Clinico-pathological classification of rheumatic mitral valve damage and surgical strategy

BackgroundThere is a lack of established pathological indications for rheumatic valve repair. Therefore, we summarized the pathological classifications of rheumatic heart diseases and their correlations with the surgical strategies.MethodsThis observational study enrolled patients with rheumatic heart diseases who underwent mitral valve repair (MVP) or replacement at our centre between January 2017 and January 2019. Mitral leaflet, mitral commissural, and sub-valvular apparatus were classified into three grades from mild to severe, according to their degree of pathological damage. Based on certain principles and the grade of mitral leaflet, mitral commissural, and sub-valvular apparatus damage, three pathological types were identified (types I to III), based on which all patients were classified. The features of each pathological type were summarised. Differences between the three pathological types were analysed using chi-square test of tendency. These data were used to propose a clinico-pathological classification of rheumatic mitral valve damage in Chinese patients.ResultsOf 398 patients, 284 (70%) underwent MVP for rheumatic mitral valve diseases. There were 58 type I (15%) patients in the study, all of whom underwent repair (repair rate, 100%). Preoperative moderate-to-severe regurgitation with mild pathological lesions was observed in 64% of these patients. In 260 type II (65%) patients, the repair rate was 76% (197/260); preoperative moderate-to-severe stenosis was observed in 88% of these patients. In 80 type III (20%) patients, the repair rate was 36% (29/80); the preoperative rates of extremely severe stenosis and moderate-to-severe regurgitation in these patients were 50% and 40%, respectively. Several preoperative parameters show the change in trend with the increase in the pathological classification severity.ConclusionsOur clinico-pathological classification of rheumatic mitral valve damage is applicable to MVP. Considering that the classification principles are based on the possibility of mitral repair, it provides a phased and achievable target ratio for MVP and a principle of screening patients who should undergo rheumatic MVP.     

The advantage of repair of mitral valve in acute endocarditis

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair offers a survival benefit compared with valve replacement in surgery for non-infectious mitral regurgitation. It is unclear whether repair offers an advantage for patients undergoing mitral valve surgery for active endocarditis. Morbidity and mortality (early and late) and event-free survival were compared between the repair and replacement groups. METHODS: Between September 1986 and July 1999, 44 patients with acute native mitral valve endocarditis underwent surgery; 28 patients had valve replacement, and 16 underwent repair. Nine patients had complex repairs including replacement of a portion of the leaflet with prosthetic patch, placement of artificial chordae, resection of a portion of both leaflets, and/or reconstruction of a commissure. The remainder had simple repairs. RESULTS: Preoperative characteristics and indications for surgery between the two groups were similar. There were six in-hospital (21%) and six late cardiac deaths (21%) in the valve replacement group, but no early deaths or late cardiac deaths in the repair group (p <0.05). Independent risk factors for early and late death were need for associated procedures (p <0.03) and mitral valve replacement (p <0.05). Additional risk factors for late death were diabetes mellitus (p = 0.005) and hemodynamic instability as an indication for surgery (p = 0.047). Five patients undergoing valve replacement required reoperation due to recurrent endocarditis, compared with none in the repair group (p = 0.065). Mean follow up was 39+/-33 months in the repair group, and 57+/-51 months in the replacement group. CONCLUSION: Early and late mortality and event-free survival were better in patients undergoing mitral valve repair compared with replacement for acute endocarditis. Valve repair should be carried out whenever possible in this patient group.     

Study on the mitral valve prolapse. I. Incidence in Kobe University students. II. Follow up study

Incidence of mitral valve prolapse (MVP) in 4517 students of Kobe University, and clinical features in cases with MVP were studied. MVP was detected in 42 cases by two-dimensional echocardiography, and the prevalence of MVP was 0.93 percent (42 of 4517 cases). Among 42 cases with MVP, apparent mitral regurgitation (MR) was noted in one case with severe MVP, ventricular tachycardia was detected in one and ST-T wave abnormalities were detected in 10 respectively. In another follow up study of our hospital, 14 of 85 patients followed more than one year were noted to be deterioration in echocardiographic parameters. Eight of 14 patients had severe prolapse with severe MR, but remaining 6 had mild or moderate prolapse with mild or absent of MR. However, ST-T wave abnormalities, serious arrhythmias, and low response of %FS increase on exercise were found in high incidence in 6 of mild or moderate prolapse as well as in severe prolapse. So these follow up results suggested that not only students with severe MVP but also students with mild or moderate MVP with ST-T wave changes or VPC found in university medical examination must be followed up carefully.     

Genetic mechanisms of mitral valve prolapse

Mitral valve prolapse (MVP) is a common cardiac disorder that exhibits a strong hereditary component. Defined as billowing of the mitral leaflets into the left atrium, it is the most common cause of isolated mitral regurgitation requiring surgical repair, and it can lead to congestive heart failure, endocarditis, atrial arrhythmias, and an increased risk of stroke and sudden death. Three-dimensional echocardiographic studies demonstrating the saddle shape of the mitral valve have increased the specificity of diagnosis and provided a strong phenotypic basis for genetic studies. MVP loci have been mapped to chromosomes 11, 13, and 16 by studying large families with multiple affected members, and mutations in the filamin A gene have been shown to cause familial cardiac valvular dystrophy, an X-linked form of MVP. Determination of the genetic basis of MVP is important because the disease often manifests clinically in the fifth or sixth decade of life through presentation as a severe cardiac event. Earlier intervention in genetically susceptible individuals could potentially arrest or prevent progression to a clinically severe stage. on behalf of the Leducq Mitral Valve Consortium     

青少年特发性二尖瓣脱垂的超声评价及其与HLA的相关性研究

目的：评价青少年特发性二尖瓣脱垂（MVP）的超声诊断价值及特点，探讨HLA与特发性MVP的相关性。方法：回顾性分析29例经手术及病理证实的特发性MVP伴有严重二尖瓣关闭不全的超声检查结果：用PCR－SSP方法检测29例福建籍特发性MVP患HLA－DR的特异性抗原频率，并与65例本地区正常人相对照。结果：29例中有20例被二维超声正确诊断为特发性MVP，其中3例仅在心尖四心腔可见瓣膜脱垂，超声显像示瓣叶冗长、不增厚、无粘连，瓣口面积大；另9例被超声误诊为风湿性病变，超声显像示二尖瓣均有不同程度增厚及粘连，舒张期二尖瓣开放稍呈穹隆样；但均无钙化，且合并有严重的二尖瓣关闭不全。特发性MVP的HLA－DR15抗原频率明显增高，有显差异（P＜0．05）。结论：青少年患瓣膜脱垂伴有严重关闭不全而无明显瓣膜粘连、增厚及狭窄均应考虑患有本病。此外特发性MVP的发病与HLA－DR15的异常表达有关。