The results of treatment of heart valve disease have improved steadily duri
ng the past 20 years. In aortic stenosis,although postoperative survival ra
tes approximated those of age-matched controls, the outcome of surgery to t
reat ischemic and non-ischemic mitral regurgitation was grave. The reasons
for this were two-fold: first, patients were referred for surgery late in t
he course of their disease, when irreversible left ventricular (LV) dysfunc
tion prevented postoperative restoration of contractile function. Second, t
he value of the mitral Valve apparatus in facilitating LV contraction was u
nrecognized, and this structure was often removed at surgery, in turn worse
ning pre-existent LV dysfunction. Consequently, patients with LV dysfunctio
n due to mitral regurgitation underwent surgery that caused further damage
to the left ventricle. Not surprisingly, postoperative LV function was poor
, congestive heart failure persistent, and lifespan shortened. More recentl
y, however, substantial insight has been gained into the value of the mitra
l valve apparatus, the causes of LV dysfunction in mitral regurgitation, an
d into the objective markers of LV function that permit the clinician to re
commend surgery before muscle dysfunction has become severe and irreversibl
e.