Mitral valve replacement for regurgitation in an infant with Marfan’s syndrome

Two-dimensional and Doppler echocardiographic and pathologic characteristics of the infantile Marfan syndrome

Since the clinical, 2-dimensional and Doppler echocardiographic and pathologic findings in infantile Marfan syndrome have not been documented in detail, a study of 9 such infants was performed. The previously reported 64 cases were reviewed and the salient findings in 22 additional cases were discussed. The age at diagnosis in our 9 cases ranged from birth to 12 months (mean 2.7 months). Mitral valve prolapse was demonstrated in all, with mitral regurgitation in 8. Tricuspid valve prolapse was present in 8, with tricuspid regurgitation in 6. Marked aortic root dilatation was present in all, and was progressive. The aortic root assumed a "clover leaf" appearance in the parasternal short-axis view. Aortic regurgitation was documented initially in 1 patient, and developed during follow-up in 4 of 7 infants. Dilation of the pulmonary arterial root and pulmonary regurgitation were found in 3 of 7 infants. Severe heart failure associated with mitral or tricuspid regurgitation was present in 7 of the 9 patients. Four infants died during the first year of life. The salient pathologic features were myxomatous thickening and redundancy of the mitral and tricuspid leaflets, marked elongation of chordae tendineae and prominent dilatation of the aortic and pulmonary roots. Histologically, the collagen and elastic fibers were severely disrupted, disarrayed and fragmented with increased interstitial ground substance. These data document that infantile Marfan syndrome is characterized by clinical and morphologic features that are distinctly different from the classic syndrome seen in adolescents and adults. The aforementioned findings should facilitate early clinical and echocardiographic diagnosis of infantile Marfan syndrome.

The Marfan syndrome in early childhood: analysis of 15 patients diagnosed at less than 4 years of age

The clinical, cardiac and echocardiographic features were reviewed of 15 consecutive infants and children with the Marfan syndrome who presented at less than 4 years of age. The 10 females and 5 males were diagnosed at a mean age of 18 months (range 2 days to 3.5 years); 13 were followed up for a mean of 45 months (range 8 to 109 months) and 2 were lost to follow-up. On first evaluation, 5 patients had mitral regurgitation (MR) and none had aortic regurgitation (AR). Echocardiography showed aortic root dilatation in 9 and mitral valve prolapse (MVP) in 9; only 2 patients had a normal echocardiogram. At follow-up examination, all patients had aortic root dilatation; the rate of increase in aortic root diameter was generally greater than predicted on the basis of body surface area. One patient had AR at age 10 years. All 13 patients had MVP; 9 had progressive mitral valve dysfunction and 4 had mitral valve replacement. One patient died immediately postoperatively. Thus, aortic root dilatation is usually present in early childhood and serves as an objective indicator of the Marfan syndrome. MVP is common and MR, which may require valve replacement, is the leading cause of cardiovascular morbidity in childhood. Echocardiography is useful in the diagnosis and routine management of infants and children in whom the Marfan syndrome is suspected.

Mitral valve dysfunction in the Marfan syndrome. Clinical and echocardiographic study of prevalence and natural history

Although mitral regurgitation and fibromyxomatous thickening of the mitral leaflets have long been recognized as such, mitral valve prolapse has only recently been added as one of the pleiotropic features of the Marfan syndrome. The prevalence, age of onset, and natural history of mitral valve dysfunction in this condition are uncertain. Therefore, all patients in one clinic who met strict diagnostic criteria for the Marfan syndrome and who had clinical and echocardiographic examinations before age 22 years were reviewed. Of the 166 patients (84 males, aged 11.9 +/- 0.6 years [mean +/- SEM]; and 82 females, 11.0 +/- 0.6 years), 52 percent had auscultatory and 68 percent had echocardiographic evidence of mitral valve dysfunction, generally mitral valve prolapse. Prevalence did not differ between the sexes. Follow-up in 115 patients averaged five examinations over a mean of four years; 17 percent were followed for more than six years. Criteria for progression of mitral valve dysfunction were: (1) on auscultation, the appearance of new systolic clicks or apical systolic murmurs, a mitral regurgitant murmur increased by two grades, or appearance of congestive heart failure not due to aortic regurgitation; and (2) on echocardiography, the new appearance of mitral valve prolapse or abnormally increased left atrial dimension. Nearly half the patients met at least one criterion and one quarter had both auscultatory and echocardiographic evidence of progressive mitral valve dysfunction. Twice as many females demonstrated worse mitral valve function with time. Eight of the 166 patients either died as a result of mitral valve dysfunction or required mitral valve replacement. Severe mitral regurgitation developed in an additional 15 patients. Rupture of chordae tendineae was uncommon. Antibiotic prophylaxis was routine, and no cases of bacterial endocarditis of the mitral valve occurred. These results suggest that mitral valve dysfunction is extremely common in young patients with Marfan syndrome and usually presents as mitral valve prolapse. Serious mitral regurgitation develops in one of every eight patients by the third decade. Thus, the prevalence and natural history of mitral valve prolapse in the Marfan syndrome appear distinct from mitral valve prolapse associated with other conditions, including idiopathic or familial mitral valve prolapse.

Mechanical and histological study of aortic valve tissue from a patient with Marfan's disease

A comparison between a normal and a Marfan's disease aortic valve has been attempted in terms of their tissue stress-strain characteristics and their histology. The diseased valve tissue was found to be more compliant by an order of magnitude than the normal valve, which is related to the disorientation of its collagen fibers, and the proliferation of mucopolysaccharides.