ejection fraction

[kllang]

I am 54 and female - father died at 57 from myocardial infarction in 1979 - had been on medication for heart murmur believed to have been brought on by rheumatic fever he had as a child; brother has cardiomyopathy at 42 (diagnosed this year); 3 sisters with no known heart disease; mother is 77 and recent stress tests and carotid doppler all fine.  My recent EKGs (last 5 years) show different abnormalities, but cardiac specialist considers false positives due to echocardiogram and nuclear stress tests results (holter test and stress done 5 years ago - all ok then and the above tests were performed in May this year).  I run on the treadmill 3-5 days per week (depending on my schedule) up to 5.5 mph with no problems.  My only symptom is heart palpitations if I have caffeine - try to avoid it most of the time.  Now, on the recent tests mentioned above, I had two different ejection fractions.  The echo fraction was 57% and the nuclear was 71%.  The doctor did not explain anything other than to say my heart was normal in size, normal function with no blockages.  Once I read through copies of the test results for myself - I am ok with most everything except the difference in the ejection fractions - and naturally am a little concerned with the echo percentage.  Results also showed trace insufficiency in mitral and tricuspid valves, which I understood is not necessarily something to be concerned with.  What do you think - why such a difference in the fraction results and what do you think about the valve insufficiency?

[kenkeith]

There will be normal variation of the EF as the heart compensates to maintain equilibrium or balance of blood flow between the heart's right and left side.  To normally compensate EF increases (range 55-75%) by dilating the LV chamber and that increases contractual strength and blood volume in keeping with physics (FRANK/STARLING mechanism) thereby enhancing performance.  

The EF usually represents the percentage of blood pumped into circulation with each stroke, but with mitral valve insufficiency there is an amount something less than estimated EF goes into circulation as some blood flows back into the upper chamber.