"Myxomatous" mitral valves: collagen dissolution as the primary defect.

King, Bernard D.; Clark, Michael A.; Baba, Nobuhisa; Kilman, James W.; Wooley, Charles F.

doi:10.1161/01.cir.66.2.288

Cited by 95 publications

(33 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most specific histopathologic characteristics are collagen dissolution and disruption in the pars fibrosa of the mitral valve leaflets. Also, there is a replacement of the dense collagenous fibrosa by loose myxomatous connective tissue [38,39]. Similar histologic abnormalities have been seen in chordae tendineae.…”

Section: Diagnostic Considerationsmentioning

confidence: 95%

Floppy Mitral Valve (FMV)/Mitral Valve Prolapse (MVP) and the FMV/MVP Syndrome: Pathophysiologic Mechanisms and Pathogenesis of Symptoms

Boudoulas¹,

Boudoulas

2013

Cardiology

View full text Add to dashboard Cite

Mitral valve prolapse (MVP) results from the systolic movement of a portion or segments of the mitral valve leaflets into the left atrium during left ventricular systole. It is well appreciated today that floppy mitral valve (FMV) is the central issue in the MVP and mitral valve regurgitation (MVR) story. The term FMV refers to the expansion of the area of the mitral valve leaflets with elongated chordae tendineae, chordae rupture and mitral annular dilation. FMV/MVP occurs in a heterogeneous group of patients with a wide spectrum of mitral valve involvement from mild to severe. Two types of symptoms can be defined in FMV/MVP patients. In one group of patients, symptoms are directly related to progressive MVR. In the other group, symptoms cannot be explained by the degree of MVR alone; activation of the autonomic nervous system has been implicated for the explanation of symptoms in this group of patients which is referred to as the FMV/MVP syndrome. In this brief review, the natural history, pathophysiologic mechanisms and management of patients with FMV/MVP/MVR and FMV/MVP syndrome are discussed.

show abstract

Section: Diagnostic Considerationsmentioning

confidence: 95%

Floppy Mitral Valve (FMV)/Mitral Valve Prolapse (MVP) and the FMV/MVP Syndrome: Pathophysiologic Mechanisms and Pathogenesis of Symptoms

Boudoulas¹,

Boudoulas

2013

Cardiology

View full text Add to dashboard Cite

show abstract

“…37 These tissue level changes cause MV leaflets with myxomatous disease to become thickened and enlarged, and the redundant tissue of these leaflets leads to poor leaflet coaptation and MR. 37 Morphologic analysis of myxomatous MVs has shown a greater than two-fold increase in valve surface area, due to significant increases in both the anterior and posterior leaflet surface areas. 25 Additionally, the structural elements of the MVcollagen, elastin, and proteoglycans -constitute approximately 85-95% of leaflet dry weight, 7,28 indicating that alteration of these components will significantly affect leaflet mechanical properties. Myxomatous leaflets have previously been shown to be more extensible and less than half as strong as normal leaflets, further contributing to leaflet prolapse and MR. 5 Similar enlargement and extensibility changes can also occur in the chordae tendineae, in which the chords become thickened and elongated, leading to leaflet billowing into the atrium during systole.…”

Section: Mvp Due To Degenerative Mrmentioning

confidence: 99%

Development of a Simultaneous Cryo-Anchoring and Radiofrequency Ablation Catheter for Percutaneous Treatment of Mitral Valve Prolapse

Boronyak

Merryman

2012

Ann Biomed Eng

View full text Add to dashboard Cite

“…1 Despite well-characterized histological changes of myxomatous degeneration with accumulation of glycosaminoglycans, collagen fragmentation, disorganized extracellular matrix (ECM), and increased expression of proteolytic enzymes, the molecular pathogenesis is not well defined. [2][3][4] A leading cause of isolated mitral regurgitation, MVP is associated with various complications such as infectious endocarditis, heart failure, atrial fibrillation, stoke, and death. 5,6 Most MVP seen in clinical practice is sporadic and of unknown etiology, but an indication of transforming growth factor (TGF)-␤ involvement derives from both familial and syndromic MVP.…”

mentioning

confidence: 99%

Modulation of Transforming Growth Factor-β Signaling and Extracellular Matrix Production in Myxomatous Mitral Valves by Angiotensin II Receptor Blockers

et al. 2012

View full text Add to dashboard Cite

Background-Little is known about the pathophysiology of myxomatous degeneration of the mitral valve, the pathological hallmark of mitral valve prolapse, associated with symptomatic mitral regurgitation, heart failure, and death. Excess transforming growth factor (TGF)-␤ signaling is known to cause mitral valve degeneration and regurgitation in a mouse model of Marfan syndrome. We examined if TGF-␤ signaling is dysregulated in clinical specimens of sporadic mitral valve prolapse compared with explanted nondiseased mitral valves and we tested the effects of angiotensin II receptor blockers on TGF-␤ signaling in cultured human mitral valve cells. Methods and Results-Operative specimens, cultured valve tissues, and cultured valvular interstitial cells were obtained from patients with mitral valve prolapse undergoing mitral valve repair or from organ donors without mitral valve disease. Increased extracellular matrix in diseased valve tissue correlated with an upregulation of TGF-␤ expression and signaling as evidenced by SMAD2/3 phosphorylation. Both TGF-␤ ligand and signaling mediators colocalized primarily to valvular interstitial cells suggesting autocrine/paracrine activation. In cultured valve tissue, exogenous TGF-␤ increased basal extracellular matrix production, whereas serological neutralization of TGF-␤ inhibited disease-driven extracellular matrix overproduction. TGF-␤-induced extracellular matrix production in cultured valvular interstitial cells was dependent on SMAD2/3 and p38 signaling and was inhibited by angiotensin II receptor blockers. Conclusions-TGF-␤ has a profibrotic role in the pathogenesis of sporadic mitral valve prolapse. Attenuation of TGF-␤ signaling by angiotensin II receptor blockers may represent a mechanistically based strategy to modulate the pathological progression of mitral valve prolapse in patients. (Circulation. 2012;126[suppl 1]:S189 -S197.)

show abstract

"Myxomatous" mitral valves: collagen dissolution as the primary defect.

Cited by 95 publications

References 45 publications

Floppy Mitral Valve (FMV)/Mitral Valve Prolapse (MVP) and the FMV/MVP Syndrome: Pathophysiologic Mechanisms and Pathogenesis of Symptoms

Floppy Mitral Valve (FMV)/Mitral Valve Prolapse (MVP) and the FMV/MVP Syndrome: Pathophysiologic Mechanisms and Pathogenesis of Symptoms

Development of a Simultaneous Cryo-Anchoring and Radiofrequency Ablation Catheter for Percutaneous Treatment of Mitral Valve Prolapse

Modulation of Transforming Growth Factor-β Signaling and Extracellular Matrix Production in Myxomatous Mitral Valves by Angiotensin II Receptor Blockers

Contact Info

Product

Resources

About