In Vivo Measurements of Biophysical Properties of a Heart and Aorta in a Mouse Model of Marfan Syndrome

Abstract

In Marfan Syndrome (MFS) patients cardiovascular complications are the most life-threatening manifestations and death is often sudden due to aortic dissection and rupture. Echocardiography is critical in the diagnosis and follow-up of MFS patients to detect and evaluate their cardiovascular phenotype. High frequency echocardiography was used to investigate the structural and functional properties on 6-and 12-mo WT and MFS [Fbn1 (C1039G/+)] mice (n = 8). The data show that Pulse Wave Velocity (PWV) was significantly increased in 6-mo MFS vs. WT (366.6 ± 19.9 vs. 205.2 ± 18.1 cm/s; p < 0.001) and 12-mo MFS vs. WT (459.5 ± 42.3 vs. 205.3 ± 30.3 m/s; p = 0.001) and the PWV increased directly in proportion to age in MFS mice but not in WT mice. LV mass (3.06 ± 0.16 vs. 2.46 ± 0.09 μm/g; p = 0.007) was significantly increased in 6-mo MFS mice compared with WT. We also found a significantly enlarged aortic root, decreased E/A ratio, prolonged isovolumic relaxation time and increased myocardial performance index in MFS mice compared with WT for both age groups. This study shows significant aortic dilation and central aortic stiffness in the MFS mice which are associated with LV hypertrophy, systolic and diastolic dysfunction. Moreover, the symptoms progressed with increasing age from six months to twelve months.