michael s
(Michael S)
#1
41 When should we operate to relieve mitral
regurgitation?
Tom Treasure
There are three circumstances when surgery is required for mitral
regurgitation:
1 To save life in the acute case
Sudden mitral regurgitation following rupture of degenerative
chordae tendineae, papillary muscle rupture, or endocarditis may
be very poorly tolerated. The surgeon may be presented with a
patient in pulmonary oedema, even ventilated, and then an oper-
ation may be the only way to save life.
2 The symptomatic patient with chronic mitral regurgitation
Surgical relief of regurgitant valve lesions can bring dramatic
relief. The decision is not always easy but a sensible appraisal
of the risks and benefits is what is needed. If there is a
tolerably good ventricle, and substantial regurgitation to
correct, then the benefits are likely to outweigh the risks. The
degree of left venticular dilatation to be tolerated before
surgery is required has reduced. In general, it is now suggested
that a left ventricular end-systolic dimension (LVESD) of
4.5cm is a sensible threshold for “perhaps not waiting any
longer”.
3 Mitral regurgitation and the dilated ventricle
The third scenario is the most difficult. Some patients seem to
tolerate mitral regurgitation quite well with a large ventricle
ejecting partly into a large, relatively low pressure left atrium.
The left ventricle may not be as good as it appears because the
high ejection fraction is into low afterload. If you continue to wait
the risks only get higher. Any increasing tendency in LVESD is
ominous and the onset or progression of symptoms should
prompt operation to protect the future.
