Functional, constitutional, or degenerative disorder of the mitral valve.
Mitral Valve Prolapse; Familial Mitral Regurgitation; Floppy Mitral Valve; Familial Myxomatous Valvular Disease; Myxomatous Mitral Valve Prolapse; Myxomatous Degeneration of the Mitral Valve; Click-Murmur Syndrome.
First described in 1963 by the South African cardiologist John Bereton Barlow (1924-2008) and colleagues, who angiographically confirmed the occurrence of mitral regurgitation in patients with the auscultatory finding of “Click-Murmur” Syndrome.
Mitral valve prolapse (MVP) is the most common cause of nonischemic mitral regurgitation referred for surgery in the Western world and found in 2 to 5% of the adult general population. (Mitral regurgitation caused by rheumatic fever is the most common type in developing countries.) A female predominance has historically been reported, but newer studies employing stricter diagnostic criteria found an even distribution between both genders.
In the majority of MVP cases, inheritance is autosomal dominant; however, X-linked inheritance has also been described. In some cases, the defect has been linked to chromosome 16p, although the responsible gene has not been identified, yet. Penetrance of MVP is highly variable with significant differences in the clinical picture even among affected family members.
Based on clinical examination, echocardiography, and family history. Due to its high sensitivity and specificity, cardiac MRI is increasingly used as a diagnostic tool. Secondary forms of mitral valve anomalies (eg, endocarditis) must be excluded. If the lesion is associated with atypical chest pain, exertional dyspnea, low blood pressure, palpitations, syncope, electrocardiographic repolarization anomalies (or other autonomous dysfunctions), anxiety or lean body habitus, then this constellation is often referred to as MVP Syndrome. Mitral valve prolapse describes the systolic displacement of mitral leaflet tissue into the left atrium past the mitral annular plane. Echocardiographic confirmation of MVP requires a single or bi-leaflet prolapse of at least 2 mm beyond the long-axis annular valvular plane into the left atrium during left ventricular systole, with or without thickening of the mitral leaflet. Classic MVP refers to thickening of the mitral leaflets more than 5 mm, while nonclassic MVP describes mitral leaflets whose thickness is less than 5 mm. Myxomatous degeneration describes the pathologic accumulation of proteoglycans in the spongiosa layer of the mitral valve, the structural changes in all collagen components of the leaflet and in the chordae tendineae. These changes can result in chordal rupture, a common finding in in MVP. Primary (nonsyndromic or idiopathic) is distinguished from secondary (syndromic) MVP. Syndromic MVP is associated with generalized connective tissue disorders such as ☞Marfan Syndrome (MVP in up to 75% of patients), ☞Loeys-Dietz Syndrome (MVP in up to 35%), ☞Ehlers-Danlos Syndrome (MVP in 6%), ☞Osteogenesis Imperfecta, Pseudoxanthoma Elasticum, Aneurysms-Osteoarthritis Syndrome (MVP in 45%), or Adult Polycystic Kidney Disease. ...