Floppy mitral valve/mitral valve prolapse syndrome: Beta-adrenergic receptor polymorphism may contribute to the pathogenesis of symptoms

Abstract

This study shows a large proportion of patients with FMV/MVP, predominantly women, had symptoms consistent with the FMV/MVP syndrome for many years prior to the development of significant MVR, and thus symptoms cannot be attributed to the severity of MVR alone. Further, women with FMV/MVP syndrome, symptoms at least partially may be related to β1-adrenergic receptor polymorphism, which has been shown previously to be associated with a hyperresponse to adrenergic stimulation.

Matrix Metalloproteinase Polymorphisms in Patients with Floppy Mitral Valve/Mitral Valve Prolapse (FMV/MVP) and FMV/MVP Syndrome

“…All patients were of Greek descent. Detailed phenotypic characteristics of patients studied were presented previously, including a detailed history related to type, onset, and the duration of symptoms, especially symptoms consistent with FMV/MVP syndrome [34]. Briefly, FMV/MVP and the severity of MR were established prior to surgery with 2- and 3-dimensional transthoracic and transesophageal echocardiography; FMV was also documented in the operating room by the surgeons.…”

“…Mitral leaflet prolapse was posterior in 53, anterior in 4, and bileaflet in 41 patients (Table 1). All patients had an apical holosystolic murmur prior to surgery consistent with significant MR [12,34]. Ninety-nine individuals (70 men and 29 women) with a mean age of 64 ± 13 years and without evidence of any disease were used as controls.…”

“…The duration of symptoms consistent with FMV/MVP syndrome was long and occurred many years prior to surgery; therefore, symptoms in this group of patients cannot be attributed to the severity of MR alone. The incidence of symptoms related to FMV/MVP syndrome was greater in patients with diffuse (53%) compared to patients with regional thickening (31%) of the mitral valve leaflets [34]. …”

“…Indications for surgery were based solely on severe MR and symptoms related to MR and not to symptoms related to FMV/MVP syndrome. There was no relationship between the duration of symptoms due to FMV/MVP syndrome and surgery [12,34]. …”

The evolution of mitral valve prolapse: insights from the Framingham Heart Study

“…Recent work from the Leducq MITRAL Network analyzing 1,412 mitral prolapse cases compared with 2,439 controls revealed a LMCD1 (LM and cysteine-rich domains 1), which encodes a transcription factor associated with atrioventricular valve regurgitation (7). Familial analysis has also implicated DCHS1 and beta-adrenergic receptor polymorphisms as playing a role in mitral prolapse (8,9). However, the role of genetic testing in risk-stratifying patient's remains years away from clinical application especially since the genetic basis for mitral prolapse is complex and likely involves multiple genetic loci.…”