Abstract
Background Floppy mitral valve/mitral valve prolapse (FMV/MVP), a heritable disorder of connective
tissue, often leads to mitral regurgitation (MR) and is the most common cause for
mitral valve surgery in developed countries. Connective tissue disorders may affect
aortic function, and a stiff aorta may increase the severity of MR. Aortic function,
however, has not been studied in FMV/MVP with MR.
Methods A total of 17 patients (11 men, 6 women) with FMV/MVP and significant MR were compared
with 20 controls matched for age and gender. Aortic diameters (AoD) were measured
from left ventriculograms at 2 and 4 cm above the aortic valve. Aortic pressures were
measured directly using fluid-filled catheters. Aortic distensibility was calculated
using the formula: 2(systolic AoD—diastolic AoD)/(diastolic AoD x pulse pressure).
Results Aortic distensibility was significantly lower in FMV/MVP compared with control at
2 cm above the aortic valve (1.00 ± 0.19 versus 3.78 ± 1.10 10−3 mm Hg−1, respectively; p = 0.027) and 4 cm above the aortic valve (0.89 ± 0.16 versus 3.22 ± 0.19 10−3 mm Hg−1, respectively; p = 0.007). FMV/MVP patients had greater left ventricular (LV) end-systolic (88 ± 72
mL versus 35 ± 15 mL, p = 0.002) and end-diastolic (165 ± 89 mL versus 100 ± 41 mL, p = 0.005) volumes, and lower LV ejection fraction, compared with control (50 ± 12%
versus 57 ± 6%, p = 0.034).
Conclusion Aortic distensibility is decreased (consistent with a stiff aorta) in patients with
FMV/MVP and MR. A stiff aorta may increase the severity of MR. Thus, abnormal aortic
function, which also deteriorates with age, may play an important role in the natural
history of MR due to FMV/MVP.
Keywords
floppy mitral valve - mitral valve prolapse - aorta - distensibility
