How do LA volume indices and LA diameter measurements relate to my mild mitral regurgitation?

I have mild mitral regurgitation. In June 2012, my EF (ejection fraction) was 65%, LA (left atrial) vol index 17 ml/m2 and LA dia 3.7. In October 2013, my EF was still good (65%), however, my LA vol index was 26 ml/m2 and LA dia 3.8. Does this mean, even though the regurgitation is still mild, that it has progressed because of the other numbers?

Submitted by Judi from New York on 01/07/2014

by Raymond F. Stainback, MD

Mild mitral regurgitation (MR) implies that the degree of mitral regurgitation is not of hemodynamic significance, i.e., unlikely to affect left atrial size. The left atrium is difficult to measure and the volume may vary a bit between exams due to technical difficulties in measuring this irregularly shaped structure. This alone could explain the reported difference in LA size. Since both of the LA measures are in the normal range and if the MR is mild, there would seem to be no reasons for concern. The LA volume does increase, by the way, due to other factors besides MR, such as hypertension and aging.