Form Of Mitral Valve Prolapse Research Articles

Arrhythmic form of mitral valve prolapse: presentation, risk stratification and management

Abstract Background Mitral valve prolapse (MVP) is a common finding that has been considered as benign condition for a long time. However, some anatomic forms have been recently recognized to be associated with life-threatening ventricular arrhythmia and sudden cardiac death (SCD), recently known as arrhythmic MVP (AMVP). Objectives This study is aiming to clinically characterize and risk stratify patients with malignant phenotype of MVP of high risk for ventricular arrhythmia which may lead to SCD. We aim to explore characteristics and assess potential markers for MVP induced ventricular arrhythmia that might need monitoring and follow up with medical or invasive treatment as implantable cardioverter-defibrillator, catheter ablation or even surgical repair. Methods A prospective cohort study of 45 (age 35±8, 29 females), consecutive patients with MVP and/or mitral annular disjunction (MAD) and comprehensive clinical arrhythmia on resting electrocardiography (ECG) or 48-hours Holter monitoring , Doppler echocardiography and contrast based cardiac magnetic resonance (CMR) characterization were identified. Patients were followed-up for a period of maximum one year to identify any further management needed. Results Frequent ventricular arrhythmia was evidently seen associated to MVP (69% with at least ventricular ectopy ≥5%), as well as complex ventricular arrhythmia (31% with sustained or non-sustained ventricular tachycardia ) P<0.001. AMVP was strongly associated with premature ventricular contractions (PVCs) having Right bundle branch block (RBBB) morphology on ECG and late gadolinium enhancement (LGE) on CMR (all p<0.05). Furthermore, it was shown to be associated with bileaflet prolapse and higher left ventricular volumes, however not statistically significant. On Follow-up, Out of 36 patients with ventricular arrhythmia, 64% were controlled on medical anti-arrhythmic and some others were referred either for ablation after worsening of symptoms despite of medical treatment (27.8%), implantable cardioverter-defibrillator device for secondary VT prophylaxes (5.6%) or surgery (2.8%) due to progression in mitral regurgitation severity and deterioration of symptoms. Conclusion In this small cohort study, characteristic form of MVP was found to be associated with ventricular arrhythmia more common in the form of frequent PVCs and less common in the complex form. Although majority of patients were controlled on medical treatment, few patients required further invasive management despite of medical treatment . Thus, arrhythmia associated with a special form of MVP could be life threatening and needs close monitoring, long follow-up and proper management approach to prevent SCD. Large prospective studies with comprehensive approach and long term follow up is pivotal. CMR T1 mapping and electro anatomical CARTO mapping could help in better detection and proper defining of arrhythmia substrate in future studies.AMVP illustration

The MIDA-Q Mortality Risk Score: A Quantitative Prognostic Tool for the Mitral Valve Prolapse Spectrum.

Mitral valve prolapse (MVP) is responsible for a considerable disease burden but is widely heterogeneous. The lack of a comprehensive prognostic instrument covering the entire MVP spectrum, encompassing the quantified consequent degenerative mitral regurgitation (DMR), hinders clinical management and therapeutic trials. The new Mitral Regurgitation International Database Quantitative (MIDA-Q) registry enrolled 8187 consecutive patients (ages 63±16 years, 47% women, follow-up 5.5±3.3 years) first diagnosed with isolated MVP, without or with DMR quantified prospectively (measuring effective regurgitant orifice [ERO] and regurgitant volume) in routine practice of 5 tertiary care centers from North America, Europe, and the Middle East. The MIDA-Q score ranges from 0 to 15 by accumulating guideline-based risk factors and DMR severity. Long-term survival under medical management was the primary outcome end point. MVP was associated with DMR absent/mild (ERO <20 mm2) in 50%, moderate (ERO 20-40 mm2) in 25%, and severe or higher (ERO ≥40 mm2) in 25%, with mean ERO 24±24 mm2, regurgitant volume 37±35 mL. Median MIDA-Q score was 4 with a wide distribution (10%-90% range, 0-9). MIDA-Q score was higher in patients with EuroScore II ≥1% versus <1% (median, 7 versus 3; P < 0.0001) but with wide overlap (10%-90% range, 4-11 versus 0-7) and mediocre correlation (R2 0.18). Five-year survival under medical management was strongly associated with MIDA-Q score, 97±1% with score 0, 95±1% with score 1 to 2, 82±1% with score 3 to 4, 67±1% with score 5 to 6, 60±1% with score 7 to 8, 44±1% with score 9 to 10, 35±1% with score 11 to 12, and 5±4% with MIDA-Q score ≥13, with hazard ratio 1.31 [1.29-1.33] per 1-point increment. Excess mortality with higher MIDA-Q scores persisted after adjustment for age, sex, and EuroScore II (adjusted hazard ratio, 1.13 [1.11-1.15] per 1-point increment). Subgroup analysis showed persistent association of MIDA-Q score with mortality in all possible subsets, in particular, with EuroScore II<1% (hazard ratio, 1.08 [1.02-1.14]) or ≥1% (hazard ratio, 1.11 [1.08-1.13]) and with no/mild DMR (hazard ratio, 1.14 [1.10-1.19]) or moderate/severe DMR (hazard ratio, 1.13 [1.10-1.16], all per 1-point increment with P<0.0001). Nested-model and bootstrapping analyses demonstrated incremental prognostic power of MIDA-Q score (all P<0.0001). This large, international cohort of isolated MVP, with prospective DMR quantification in routine practice, demonstrates the wide range of risk factor accumulation and considerable heterogeneity of outcomes after MVP diagnosis. The MIDA-Q score is strongly, independently, and incrementally associated with long-term survival after MVP diagnosis, irrespective of presentation, and is therefore a crucial prognostic instrument for risk stratification, clinical trials, and management of patients diagnosed with all forms of MVP.

Abstract 11528: Predictors of Ventricular Arrhythmia in Mitral Valve Prolapse

Introduction: The arrhythmic form of mitral valve prolapse (AMVP) is characterized by complex or frequent ventricular arrhythmia (cfVA) and associated with increased risk of sudden cardiac death (SCD) from ventricular fibrillation, the majority of reported cases of SCD being in premenopausal women. There is limited data on prevalence and predictors of AMVP. Methods: We studied all 645 patients aged 18 to 90 years with mitral valve prolapse (MVP) on echocardiography between 2016-2019 at our institution (median age [IQR] 63.6 [51.9-73] years; 52.4% female; 16.2% African American). Echocardiogram images were reviewed to analyze valve morphology, mitral regurgitation (MR) severity and ventricular structure and function. cfVA was identified from resting and ambulatory ECG tracings. These and cardiovascular risk factors associated with cfVA were analyzed using multivariate logistic regression. Results: cfVA was present in 188 (29.1%) MVP patients. Independent predictors of cfVA were mitral annular disjunction (MAD, odds ratio [OR, 95% CI] 2.45 [1.48 – 4.06], p=0.0005), bi-leaflet prolapse (2.10 [1.42 – 3.11] vs. uni-leaflet, p=0.0002), inferior ECG T-wave inversion (TWI, 1.79 [1.17-2.75], p=0.007) and moderate+ MR (1.52 [1.01-2.27], p=0.044). AMVP, defined as bi-leaflet MVP with cfVA, was present in 102 (15.8%), with MAD in 38 (37.3%, vs. 58 [10.7%] without AMVP, p&lt;0.0001), inferior lead TWI in 45 (44.1%, vs. 97 [17.9%], p&lt;0.0001) and moderate+ MR in 47 (46.1% vs 134 [24.7 %], p&lt;0.0001). After median 1221 (IQR 1013 – 1456) days follow-up, 12 with AMVP died (11.7%, vs. 45 [8.3%] without, p=0.256) with SCD in 2 (2.0%, vs. 4 [0.9%], p=1.00). Conclusion: Ventricular arrhythmia in MVP is predicted by MAD, bi-leaflet prolapse, inferior ECG TWI and MR. These findings may help identify otherwise asymptomatic individuals, such as premenopausal women with MVP, at increased risk of SCD.

Mechanistic insights of the left ventricle structure and fibrosis in the arrhythmogenic mitral valve prolapse.

Mitral valve prolapse (MVP) is a common and benign condition. However, some anatomic forms have been recently associated with life-threatening ventricular arrhythmias and sudden cardiac death. Imaging MVP holds the promise of individualized MVP risk assessment. Noninvasive imaging techniques available today are playing an increasingly important role in the diagnosis, prognosis and monitoring of MVP. In this article, we will review the current evidence on arrhythmogenic MVP, with special focus on the utility of echocardiography and CMR for identifying benign and “malignant” forms of MVP. The clinical relevance of this manuscript lies in the value of imaging technology to improve MVP risk prediction, including those arrhythmic-MVP cases with a higher risk of sudden cardiac death.

Marfan Syndrome with Varieties of Clinical Features

Marfan Syndrome is an autosomal dominant disorder caused by mutation in the extracellular matrix protein fibrilin-1 gene located on chromosome 15. It has variable range of expression.We describe a case of a 12 year aged girl with positive family history including lean and thin body stature, skin striae, joint hyper mobility, high arched palate, mal occlusion of teeth, pectus excavatum, winging of scapula, scoliosis of back bone, total arm span more than total body height (1.11:1), lower segment greater than upper segment (1.40:1), severe form of mitral valve prolapse and aortic root dilatation. There are a lot of features of Marfan Syndrome in our single patient which is rare in earlier available case reports.J MEDICINE Jan 2018; 19 (1) : 58-62

Three-dimensional dynamic morphology of the mitral valve in different forms of mitral valve prolapse - potential implications for annuloplasty ring selection.

BackgroundReal-time three-dimensional transesophageal echocardiography has increased our understanding of the distinct pathomechanisms underlying functional, ischaemic or degenerative mitral regurgitation. However, potential differences in dynamic morphology between the subtypes of degenerative mitral prolapse have scarcely been investigated.MethodsIn order to compare the dynamic behavior of the different phenotypes of degenerative mitral valve prolapse, real-time three-dimensional transesophageal echocardiography recordings of 77 subjects, 27 with Barlow disease (BD), 32 with Fibroelastic deficiency (FED) and 18 normal controls (NC) were analysed.ResultsGeometric annular and valvular parameters of the myxomatous patients were significantly larger compared to controls (BD vs. FED vs. NC 3D annular area: 15 ± 2.8 vs. 13.3 ± 2.4 vs. 10.6 ± 2.3cm2, all p < 0.01). Beside similar ellipticity, BD annuli were significantly flatter compared to FED. Myxomatous annuli appeared less dynamic than normals, with decreased overall 3D area change, however only the BD group differed from NC significantly (BD vs. FED vs. NC normalized 3D area change 4.40 vs. 6.81 vs. 9.69 %; BD vs. NC p = 0.000; FED vs. NC p = not significant, BD vs. FED p = 0.025).ConclusionBD and FED differ not only in terms of valve morphology, but also annular dynamics. Both pathologies are characterized by annular dilatation. However, in BD the annulus is remarkably flattened and hypodynamic, whereas in FED its saddle-shape and contractile function is relatively preserved. These features might influence the choice of repair technique and the selection of annuloplasty ring.

Differentiated approach to training loads planning in athletes based on the clinical form of mitral valve prolapse

Mitral valve prolapse is one of the most important small abnormalities of the heart, causing specialists’ interest in matters of admission to sports. The aim of the study was to improve medical support training process of athletes with different clinical forms of mitral valve prolapse. Methods and results. 59 athletes with mitral valve prolapse were examined, 188 athletes were included in the control group. It was established that the different clinical forms of mitral valve prolapse should be taken into account while sports’ physicians provide differentiated approach to the issues of access and training planning, competitive loads in athletes.

0077 : DOCK1 a new candidate gene in inherited form of mitral valve prolapse

Mitral valve prolapse (MVP) affects 2-4% of the general population and remains one of the most frequent indications for valvular surgery. So far, the only gene described in MVP, with an X-linked form of inheritance, is FLNA but only represents a small part of MVP. To this respect, we investigated a french MVP pedigree to uncover new molecular insights associated to the disease. We focus on a family of 5 affected patients characterized by a dysmorphic myxomatous phenotype with 2 operated patients. From 4 MVP patients, we performed a Whole Exome Sequencing screening. From bioinformatics analysis, we focused on rare (MAF<0.1%) functional variants shared by the 4 affected patients. Among 25 variants of interest, 11 were novel. One of them, found in a highly conserved residue (GERP=4.88), in DOCK1 (c.4646G>A; p. R1549Q) co-segregates in all affected members in the family. DOCK1 is highly expressed in the mitral valve as evidenced by RNA sequencing experiments using human mitral valve tissue. DOCK1 , encodes an atypical Rac exchange factor, Dock180, which acts as a guanine exchange factors (GEF) for small Rho family G proteins. Interestingly, Sanematsu et al. (2010) described a major role of Dock180 during cardiovascular development. Mitral valves of Dock1 depleted mice are thickened and lead to blood retention in left atrium. We currently investigate repercussions of p. R1549Q (located in GEF activity domain of Dock180) on Dock180 activity in the cellular adhesion phenotype (XCELLigence; IF assays) and GEF activity (Pull-Down assays) using a heterologous transfection system. Finally, a cohort of 285 MVP affected patients is screened to evaluate the prevalence of DOCK1 in the disease. This study reports a familial approach, coupled to an exome sequencing strategy which identifies a novel DOCK1 missense mutation associated with MVP phenotype. In vivo previous studies and cellular mechanisms learning will allow us to better understand mechanisms involved in the MVP pathogenesis.

Morphological features of heart of athletes with symptoms of connective tissue dysplasia.

Backgraund. The issue of medical monitoring of people with mitral valve prolapse during sports and recreational physical culture is widely discussed in contemporary literature. Mitral valve prolapse occurs with a frequency of 0.5% to 38.0%; it may be a manifestation of diseases with different origin and prognosis. It evidences the requirement of deep analysis and differential diagnosis by specialists to prevent complications in such athletes. Objective. The purpose of the work is to improve medical support of training process in athletes with mitral valve, based on the clinical form of mitral valve prolapse and degree of systemic involvement of connective tissue. Methods. We have examined 246 athletes aged from 7 to 40 years (average age was 16,1±5,9 years), 65.2% - women and 34.8% - men. By using anthropometry and somatoscopy signs of systemic involvement of the musculoskeletal system in dysplastic process were determined. In a state of physiological rest echocardiographic examination was performed by the standard method. As a result of echocardiographic examination athletes with mitral valve prolapse were selected – 58 people. The control group comprised 188 athletes without specified attributes. Results. The most frequent signs of the phenotypic manifestations of systemic involvement of connective tissue in the dysplastic process were dolichostenomelia, hypermobility of joints and flat feet. In the group of athletes with mitral valve prolapse signs of systemic involvement of connective tissue were detected statistically significantly more frequent. In the group with myxomatous degeneration of leaflets mitral valve prolapse was 0.12±0.12 cm, while in the athletes without myxomatous degeneration mitral valve prolapse was – 0.04±0.12 cm, (p=0.03). In individuals with mitral valve prolapse without myxomatous degeneration systemic involvement of connective tissue was maximum, indicating that mitral valve prolapse originates as a small heart defect, accompanying other classified and unclassified dysplastic syndromes, whereas in the group of athletes with mitral valve prolapse and myxomatous degeneration systemic involvement of connective tissue is lower, indicating the original nature of myxomatous mitral valve prolapse. Conclusion. 1. Different clinical forms of mitral valve prolapse require differential approaches of sports doctors in permissions and planning of training loads in sportsmen. 2. Increase in the number of musculoskeletal signs of connective tissue involvement in the dysplastic process may indicate other accompanying classified and unclassified dysplastic syndromes. 3. Increased thickness of mitral valve evidences the original nature of myxomatous mitral valve prolapse with a prognostically unfavorable course.

Chest pain in paediatric patients referred to paediatric cardiology clinic at PSCC qassim

Chest pain is a common paediatric complaint. Chest pain due to a cardiac condition is rare in children and adolescents, with a prevalence of less than 6%. History and physical exam may be sufficient for identifying the majority of significant aetiologies. Objectives To review the different causes of chest pain of patients referred to PSCC-Q Method Rertrospective analysis of our database. Follow up of patients was done with telephone call of all patients family to ask about the child and the chest pain status. Results During the period from January 2011 till December 2012, 28 patients were referred because of chest pain to the cardiac clinic. 18 (64%) were females and 10 (36%) were males. Palpitations were present in 7 of them (25%). Four patients were having noncardiac symptoms in the form of arthralgia in two and recurrent tonsillitis in two. Tow patients were having a positive family history of cardiac problems in the form of mitral valve prolapse in one and dilated cardiomyopathy in the other. General examination and Vital signs were normal in all of them. The mean ± SD of the heart rate, blood pressure and saturation were 99 ± 15 bpm, 102/63 ± 11/9 mm Hg, and 97 ± 1% respectively. The mean ± SD of the weight and height were 30 ± 16 kg and 131 ± 10 cm, respectively. Cardiovascular examination was normal in all of them. Innocent systolic murmur was present in 5 of them (18%). ECG was also normal in all of them. One patient had mild prolongation of the PR interval. Those with history of palpitations had Holter monitoring for 24 h which were normal in all of them. Chest pain was recurrent in 6 patients (22%) and was related to exertion in only one. On Followup all patients were alive and asymptomatic. Conclusion Chest pain in children usually is benign. History and physical exam usually are sufficient. Laboratory testing should be guided by History and physical exam.

Relation of mitral valve morphology and motion to mitral regurgitation severity in patients with mitral valve prolapse

BackgroundMitral valve thickness is used as a criterion to distinguish the classical from the non-classical form of mitral valve prolapse (MVP). Classical form of MVP has been associated with higher risk of mitral regurgitation (MR) and concomitant complications. We sought to determine the relation of mitral valve morphology and motion to mitral regurgitation severity in patients with MVP.MethodsWe prospectively analyzed transthoracic echocardiograms of 38 consecutive patients with MVP and various degrees of MR. In the parasternal long-axis view, leaflets length, diastolic leaflet thickness, prolapsing depth, billowing area and non-coaptation distance between both leaflets were measured.ResultsTwenty patients (53%) and 18 patients (47%) were identified as having moderate to severe and mild MR respectively (ERO = 45 ± 27 mm2 vs. 5 ± 7 mm2, p < 0.001). Diastolic leaflet thickness was similar in both groups (5.5 ± 0.9 mm vs. 5.3 ± 1 mm, p = 0.57). On multivariate analysis, the non-coaptation distance (OR 7.9 per 1 mm increase; 95% CI 1.72-37.2) was associated with significant MR. Thick mitral valve leaflet as traditionally reported (≥ 5 mm) was not associated with significant MR (OR 0.9; 95% CI 0.2-3.4).ConclusionsIn patients with MVP, thick mitral leaflet is not associated with significant MR. Leaflet thickness is probably not as important in risk stratification as previously reported in patients with MVP. Other anatomical and geometrical features of the mitral valve apparatus area appear to be much more closely related to MR severity.

Classic and non-classic forms of mitral valve prolapse

To investigate the significance of the established distinction between classic and non-classic forms of mitral valve prolapsed (MVP). We included in this prospective study all patients examined in our preventive cardiology outpatient clinics during the biannual period October 2004-October 2006. We examined in total 10.818 patients, 238 of whom (2.2%) were diagnosed for MVP. We noted relevant demographic and clinical data (gender, age of diagnosis, symptoms, need for hospitalization) and performed statistical comparisons between patients with the classic and those with the non-classic form. Follow-up controls were performed three years afterwards. Patients with the classic form had an earlier age of first diagnosis, more prominent symptoms, and more frequently diagnosis for other disorders (atrial septal defect, ventricular septal defect, Marfan syndrome, Ehlers-Danlos syndrome) than the rest of the patients; however, there were no significant differences as far as certain major complications (stroke, death, submission to surgery) were concerned. The classic form of mitral valve prolapse is more tightly associated with morbid complications, and a more frequent follow-up control in this group of patients may be useful.

Radiofrequency Ablation Directionally Alters Geometry and Biomechanical Compliance of Mitral Valve Leaflets: Refinement of a Novel Percutaneous Treatment Strategy

Myxomatous mitral valve disease is a form of mitral valve prolapse, which is characterized by a disorganized collagen matrix with excessive glycosaminoglycan content. Due to loss of mechanical competence and increased surface area of the mitral valve leaflets, this disease leads to regurgitation and cardiac dysfunction. There is a strong clinical need for percutaneous treatment of patients with myxomatous mitral valve disease and regurgitation as an alternative to open-chest surgery. We have previously examined the efficacy of radiofrequency ablation of the mitral valve leaflets as a strategy to reduce prolapse and regurgitation in a canine model. Prior to testing this strategy further in a large animal model, we sought to determine the ‘therapeutic window’ that should be targeted in vitro. Here, we quantified both the geometrical and biomechanical compliance changes of porcine mitral valve anterior leaflets before and after radiofrequency ablation at various powers (Watts) for 15 s. Following ablation, there was significant shortening in the circumferential direction after 15 and 25 W, which led to significant decreases in surface area at these powers. Under an equibiaxial membrane tension of 90 N/m, which approximates systolic loading of 120 mmHg, axial strain in the radial direction was predominantly affected following ablation with significant decreases following 10, 15, and 25 W. Circumferential strain was not different following any ablation power, except 25 W when it was significantly increased. Areal strain at 90 N/m was significantly decreased following 10 and 15 W ablations, but was increased following 25 W. These data indicate that radiofrequency ablation decreases mitral valve leaflet surface area and compliance, but only achieving both within a narrow therapeutic window. To maximize both of these effects, 15 W appears to be the target power. While 25 W leads to ~25% reduction in tissue area, it results in increased compliance. We speculate that at this power, collagen fibers may be failing due to rupture, either directly from ablation or once they are mechanically loaded.

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.

Abnormal elastic properties of the aorta in the mitral valve prolapse syndrome

Background — Mitral valve prolapse (MVP) is the most common valvular heart disease representing a generalized disease of connective tissue in the primary form. Elastic properties of the aorta with primary MVP may be expected to be increased.We aimed to determine the aortic elasticity in the primary form of MVP.Methods and results — Twenty male patients with a primary form of MVP not having any sign of Marfan syndrome and joint hyperlaxity syndrome and twenty healthy individuals were included in the study.Aortic strain, aortic distensibility index and aortic stiffness index were calculated by using aortic diameters obtained by echocardiography and blood pressures measured by sphygmomanometer. When comparing the MVP group and the control group it was found that the aortic stiffness index was increased (P<0.05) whereas the aortic distensibility and strain index were decreased (P<0.05) in the MVP group. There was no significant difference between the characteristics of the groups (P>0.05).Conclusion — We concluded that the elastic properties of the aorta were decreased in the primary form of MVP, unexpectedly.Therefore, results of decreased aortic elasticity should also be followed up in patients with MVP.

Prevalence and clinical significance of aortic valve prolapse.

The prevalence and clinical significance of aortic valve prolapse were determined prospectively in 2000 consecutive patients undergoing routine clinical cross sectional echocardiography. Two hundred and twelve patients were excluded because the aortic cusps were not adequately visualised. Aortic valve prolapse was defined as downward displacement of cuspal material below a line joining the points of attachment of the aortic valve leaflets. Twenty four cases of aortic valve prolapse (1.2%) were identified. The patients were aged 12-64 years and nine were women. All had underlying valvar heart disease and the commonest lesion (in 11 cases) was prolapse of the larger cusp in bicuspid valves. Aortic valve prolapse was seen in four patients with mitral valve prolapse (two with severe regurgitation), one of whom had marfanoid aortic root dilatation. The remaining examples of aortic prolapse were seen in patients with various disorders including one with pulmonary atresia, two with aortic root disease (one with dissection and one with idiopathic dilatation), and one case of severe mitral regurgitation. Valves destroyed by infective endocarditis were seen in two cases. Aortic valve prolapse may be detected in various cardiac disorders and does not imply the presence of aortic regurgitation, but when bicuspid aortic valves are present it may well be important in producing such regurgitation. Although aortic valve prolapse may be associated with severe forms of mitral valve prolapse, these patients rarely have aortic regurgitation.

Mitral valve prolapse.

Mitral valve prolapse is a condition that is being recognized with increased frequency. It is not known whether its incidence is increasing, or whether we are better able to diagnose it today. In the idiopathic or familial variety, the mitral valve pathology is almost always that of myxomatous degeneration. Some authors have suggested the presence of a cardiomyopathy because of significant left ventricular dysfunction in many cases. Idiopathic prolapse occurs predominantly in females, often at a young age, and may be associated with chest pain, dyspnea, fatigue, presyncope, syncope, and/or sudden death. The clinical findings are variable and typically consist of a nonejection click and/or late systolic murmur, heard best at the cardiac apex. Diagnosis can be confirmed by echocardiography and/or ventricular cineangiography, the latter permitting accurate recognition of the anatomy of the prolapsed leaflets. The complications of infective endocarditis, severe mitral insufficiency, and life-threatening ventricular arrhythmias represent the major problems of management. It is important to distinguish the idiopathic form of mitral valve prolapse from that due to coronary artery disease and to realize that mitral valve prolapse may occur in Marfan's syndrome, Turner's syndrome, or in association with secundum atrial septal defect or ruptured chordae tendineae. Typical clicks and/or murmurs have also been described in patients with a history of rheumatic fever and in hypertrophic cardiomyopathy. Although much descriptive knowledge has accumulated over the past 15 years, many unanswered questions remain regarding the idiopathic type of prolapse. What is the nature and cause(s) of myxomatous degeneration? What is the relation of the valve pathology to the left ventricular dysfunction? What is the relation of both of these factors to disabling chest pain, electrocardiographic changes, and life-threatening arrhythmias? Hopefully, answers to these and other important questions regarding mitral valve prolapse will be forthcoming.