Background:
The mitral annular (MA) geometric changes have been reported in patients with various cardiac diseases such as atrial fibrillation (Af), mitral regurgitation (MR) and dilated cardiomyopathy (DCM). The advances of real-time 3D transesophageal echocardiography (TEE) enable us to analyze the MA geometry more accurately and reliably than 3D transthoracic echocardiography (TTE). We sought to determine the independent predictors for MA geometric changes in patients with Af, significant MR, and DCM by 3D TEE.
Methods:
We examined 32 subjects by 3D TEE and 2D TTE; 6 with lone Af, 9 with mitral valve prolapse (MVP), 3 with organic MR, 6 with DCM, and 8 normal subjects. Left ventricular (LV) end-diastolic and end-systolic volume indices (EDVI and ESVI), ejection fraction (EF), left atrial volume index (LAVI), and MR severity were assessed by 2D TTE. We measured MA area index, commissural length, and MA height (Figure 1
). For the index of the saddle-shaped MA geometry, MA shape index was calculated as the (MA height)/(commissural length).
Results:
Patients with MVP and those with DCM had larger MA area index and lower MA shape index than normal subjects (all,
P
<0.05). MA area index was associated with LAVI, MR severity, and LV EDVI (all,
P
<0.05) (Figure 2
). MA shape index was associated with LV EF, ESVI, and the presence of Af (all,
P
<0.05) (Figure 3
). In multivariate analysis, LAVI, MR severity, and LV EDVI independently predicted for MA area index, and LV EF was independent predictor for MA shape index (all,
P
<0.05).
Conclusion:
MA dilatation was independently associated with larger LA and LV volumes and severer MR, not LV EF, while the saddle-shaped MA geometry was associated with LV EF.
Figure 1
Figure 2
Figure 3