mitral valve regurgitation and mild heart muscle weakness

[rfr]

I posted last week about a dx of mitral valve regurgitation and mild heart weakness.  I have since gotten the specific #'s and seen the cardiologist.   The mitral valve regurgitation is listed as mild-mod. and the EF is at 45-50%.  All other tests were normal.  The cardiologist said a mild-moderate MVR is really like a mild MVR because mild is really closer to normal.  He also said the EF was just borderline normal and that an EF of 50% is really the bottom line of normal.  He has recommended a stress echo and said that if the  EF increases while exercising then my normal heart strength is probably on the low side normally and there would be nothing wrong.  If it does not increase then there may be some mild damage(likely from a previous virus).  He does not think there would be any other cause because I am 41, thin and exercise regularly.  I also have slightly elevated blood pressure and he recommended a 24 home blood pressure monitor.

My questions are;  Does mild-mod. MVR really mean mild?,  Is an EF of 45-50% really boderline normal if the rest of the heart exam is normal?  I plan to get a second opinion but thought maybe someone else might have heard something different about MVR and EF.  I feel better that he is not really concerned but had read that any EF less than 55-60% indicates heart damage.

rfr

[kenkeith]

For some perspective: Normal EF is around 55 to 75% and is an estimate based on volume of blood pumped into circulation with each heart beat.  I believe doctors estimate on the side of caution and hedge their estimates.  

A better measurement for myocardial contractivity is fractional shortening.  FS estimates contractility by calculating a ratio of dimensions, and is calculated by the difference between end diastolic and end systolic and then divided by end diastolic.  We know some dilation of the LV is compensitory and icreases the strenght of contractions so as to provide a balance of blood flow between right and left side of the heart so there are variations with each heartbeat..  Normal range is 18 to 42%.

If your M-mode values for dimensions are normal, then your FS should be normal.  If your heart dimension is oversized that would indicate over compensation and although a higher number and a drop in EF.  

EF is an attempt to measure cardiac output based on volume, but usually it doesn't account for backflow.  Depending on the degree of regurgitation cardiac output volume would be reduced. Also, if the EF is more than 75% that could also indicate overcompensation resulting in a rapid drop in EF if not treated.

It is my understanding below 50% is a weak heart, but the margin of error in the estimate could place it in the low normal category.  Below 29% is in the heart failure range.  It is estimated that 24% of the heart disorder population are in that range and have no symptoms.  May account for cardiac arrest to what appeared to be a healthy person.  

[Momto3]

A few years ago, I found myself in a similar situation.  At the time, the doctors assessed the MR to be at least moderately severe and an EF of about 40%.  As I recall, the doctor would have been OK (not thrilled) with an EF of 50%.  I was referred for a few tests, one of them a stress test.  During all this time, I was having thousands of PVC's daily.

Anyway, the doctors were pretty sure that the declining EF was because of the worsening MR.  Further tests revealed moderate regurgitation, but not severe.  I had the stress test and my EF DID go up....My EP said that was a very good indication that the MR did NOT cause the declining EF.  I have never heard that mild-mod MR really means "mild".  Seems that would be "mild" and not "mild-mod", but maybe the doctor will explain otherwise.

I was also told that when a person has MR (not sure if it's only for significant MR), a higher EF is desirable.  That said, your EF could be entirely normal for you given that you exercise, etc.

In my case, the PVC's caused the declining EF.  Once the PVC's were elminated, my EF rose.  The last stress echo indicated the MR is "at least moderate" but the EF is back up to 60%.  

Maybe you could try posting your question on the "Expert" forum.  It would be interesting to see the doctor's response.

Hope your tests go well!