Skeletal abnormalities in mitral-valve prolapse

New insights into degenerative mitral valve disease in dogs

Degenerative mitral valve disease (DMVD) is the most common cardiac disease in dogs. Although the disease is frequently described in the veterinary literature, many aspects are still unknown or controversial. Based on recent research findings, this article addresses the etiology, pathogenesis, inheritance, diagnosis of early DMVD, diagnosis of mild decompensated heart failure, and efficacy of early medical intervention in clinically compensated dogs.

Clinical spectrum of skeletal abnormalities and mitral valve prolapse and their clinical implications

Fifty-six patients were diagnosed to have mitral valve prolapse (MVP) syndrome by auscultatory criteria, confirmed by cross-sectional echocardiography. Complete physical examination and x-ray of the bony thorax revealed bony deformities which were subdivided into four main groups according to the predominant deformity. Shallow chest with pectus excavatum, straight back, kyphoscoliosis and elliptical chest in marfanoid patients were reported in the cases studied. It is concluded that musculoskeletal abnormalities have to be considered as nonauscultatory features of MVP. Therefore, any patient with musculoskeletal deformity has to be screened for MVP by cross-sectional echocardiography to prevent life-threatening complications.

Comparison of cardiovascular and skeletal features of primary mitral valve prolapse and Marfan syndrome

The association of primary mitral valve prolapse (MVP) with thoracic bony abnormalities has led to the suggestion that MVP may be a forme fruste of the Marfan syndrome. Echocardiographic, skeletal and anthropometric findings in 59 subjects with primary MVP and 59 age- and sex-matched patients with Marfan syndrome were compared with those in 59 control subjects. Subjects with mitral prolapse were similar to control subjects and differed (p less than 0.025 to p less than 0.001) from the patients with Marfan syndrome in aortic root dimensions, height, arm span, upper/lower segment ratio and prevalences of arachnodactyly, scoliosis and pectus carinatum. Subjects with mitral prolapse and patients with Marfan syndrome had similar body mass indexes and prevalences of pectus excavatum and straight back. All 3 groups were similar in arm span/height ratio. The 5 subjects with MVP and arachnodactyly had lower weights, smaller body surface areas and smaller aortic root dimensions, and were more likely to have scoliosis than subjects with MVP without arachnodactyly. Thus, primary MVP differs from the Marfan syndrome in all major skeletal and cardiovascular features.

Mitral valve dimensions and motion and familial transmission of mitral valve prolapse with and without mitral leaflet billowing

To test the hypothesis that mitral valve prolapse may be due either to billowing of mitral leaflets into the left atrium or to dynamic expansion of the mitral anulus, mitral leaflet and annular dimensions and motion were measured by computer-assisted two-dimensional echocardiography in 35 normal adults and 48 subjects with auscultatory and M-mode echocardiographic evidence of mitral prolapse. Among normal subjects, mitral leaflet and annular dimensions tended to be larger compared with body size or left ventricular size in women than in men. Mitral leaflet billowing was observed in 24 (50%) of 48 patients with mitral prolapse and 0 of 35 normal subjects (100% specificity). The 24 patients without leaflet billowing had greater systolic expansion of the mitral anulus (p less than 0.0001) than did normal adults or patients with leaflet billowing (41 +/- 14% versus 27 +/- 12% and 22 +/- 11%, respectively) and a significantly lower body mass index (p less than 0.005 versus normal group). The ratio of anterior plus posterior mitral leaflet length to end-systolic annular diameter was lower in patients with prolapse without leaflet billowing than in normal subjects (1.09 +/- 0.12 versus 1.19 +/- 0.15, respectively, p less than 0.01) or patients with leaflet billowing (1.21 +/- 0.17, p less than 0.05). Among 35 relatives with mitral prolapse in the families of 23 patients with prolapse, the pattern was the same as in the proband in 31 (89%) (p less than 0.000002).(ABSTRACT TRUNCATED AT 250 WORDS)

Relation between clinical features of the mitral prolapse syndrome and echocardiographically documented mitral valve prolapse

Mitral valve prolapse, the most common inherited cardiovascular condition, has been associated with a variety of signs, symptoms and electrocardiographic abnormalities, but the true spectrum of the mitral prolapse syndrome remains in doubt because clinical findings often contribute to patient identification and their prevalence in patient groups may be overstated because of ascertainment bias. Accordingly, clinical findings in 88 patients with echocardiographic mitral prolapse were compared with those in 81 of their adult first degree relatives with mitral prolapse (a group free of ascertainment bias) and in two control groups without mitral prolapse: 172 first degree relatives and 60 spouses. Comparison of relatives with and without mitral prolapse demonstrated true associations between mitral prolapse and clicks or murmurs, or both (67 versus 9%, p less than 0.001), thoracic bony abnormalities (41 versus 16%, p less than 0.001), systolic blood pressure less than 120 mm Hg (53 versus 31%, p less than 0.001), body weight 90% or less of ideal (31 versus 14%, p less than 0.005) and palpitation (40 versus 24%, p less than 0.01). In contrast, relatives with mitral prolapse showed no significant increase over normal relatives or spouses without mitral prolapse in prevalence of chest pain, dyspnea, panic attacks, high anxiety or repolarization abnormalities, but these features were all more common in women than in men (p less than 0.01 to less than 0.001). Thus, the true spectrum of the mitral prolapse syndrome encompasses a midsystolic click and late systolic murmur, thoracic bony abnormalities, low body weight and blood pressure and palpitation. Other suggested clinical features, including nonanginal chest pain, dyspnea, panic attacks and electrocardiographic abnormalities, have appeared to be associated with mitral valve prolapse because of ascertainment bias and an erroneous classification of differences between men and women as being due to mitral valve prolapse.

Bodily habitus and mitral valve prolapse

We investigated the hypothesis that patients with idiopathic mitral valve prolapse (MVP) have distinctive anthropometric characteristics as part of an ill-defined connective tissue abnormality. In 100 consecutive patients with MVP identified at echocardiography, 56 women and 44 men (age range 28-78 years), we compared measurements of height, weight, arm span, upper and lower body segments, anteroposterior chest diameter, anteroposterior chest diameter/height index, body mass index, and metacarpal index with those from an age and sex matched control group. We also compared the frequency of thoracic asymmetry in MVP patients and controls. Both male and female MVP patients had lower body mass indices than their controls (p less than 0.01 and p less than 0.01 and p less than 0.001, respectively). Women with MVP were lighter than their controls (p less than 0.001) and the same trend was seen in men (p = 0.14). There were no significant differences with any of the other measurements or in the frequency of thoracic asymmetry. We conclude that patients of both sexes with idiopathic MVP are leaner than control subjects but do not otherwise have a specific bodily habitus or an increased frequency of thoracic cage abnormalities. The findings do not support the hypothesis of an underlying generalised connective tissue abnormality but raise the interesting question of why MVP patients should be lean.

Familial occurrence of mitral valve prolapse: is this related to the straight back syndrome?

Familial prevalence of mitral valve prolapse in a Chinese population was determined in 22 propositi of whom 10 had straight back (group A), three had abnormally high metacarpal index (group B), and nine had neither (group C). Of 71 (32 male and 39 female subjects) first degree relatives screened, mitral valve prolapse was found in 19 (seven male and 12 female subjects) (26.8%). The familial prevalence among groups A, B, and C was 20%, 30%, and 38.5%, respectively. Our study indicates that the familial occurrence of mitral valve prolapse does not depend on its association with the straight back syndrome.