Heart Disease Community
Why does EF vary from test to test?
About This Community:

This patient support community is for discussions relating to angina, angioplasty, arrhythmia, bypass surgery, cardiomyopathy, coronary artery disease, defibrillator, heart attack, heart disease, mitral valve, pacemaker, PAD, stenosis, and stress tests.

Font Size:
A
A
A
Background:
Blank
Blank
Blank
Blank Blank

Why does EF vary from test to test?

I recently got my records from my cardiologist, and I was looking over all my test results.  I noticed that my EF is different on every test.  I had 2 echoes, stress echo and a nuclear stress echo and none of them have the same EF.  Is one test better than the other in determining my EF.  I understand that they are estimated but there is almost a 20% difference between 2 of the tests.  Which one do I go by?  Just curious....thanks!
Related Discussions
3 Comments Post a Comment
Blank
367994_tn?1304957193
As you know EF is a measurement of the heart's pumping output in VOLUME with each stroke. The heart chambers' size is not rigid (unless hypertrohic, etc.)  but elastic and varies in dimension (LV volume capacity) to maintain a compensatory balance between the right and left chambers when there is not a dysfunctional system.

To better understand,  there is a similar test called fractional shortening (FS).  Rather than measure by VOLUME it is a measurement of the relationship between the maximum dimensions during diastole and then systole recorded with the an echo.  FS measures contractility (estimation).  It is calculated by the difference of end diastolic dimension and end systolic dimension and then divided by end diastolic dimension.  Normal range is 18 to 42%.

When end diastole is increased there are stronger contractions (Frank/Starling law of physics), but over stretched the will be a loss of contractility (dilated left ventricle).  When there is hypertrophy the muscle growth crowds out filling capacitiy and as well as stiffness affects contractions.

To answer your question which is the best to measure EF, I would say the echo.  Because the measurement is taken when the heart is/should be at a slower heart rate.  I watched the tech and he pointed and remarked on the procedure while testing, and it is apparant the border of the chambers are fuzzy because of the heart wall movement and the tech attempts (estimates) to outline border with a transducer.  A faster heart rate would be more difficult to measure and less accurate.  My opinion.

Blank
Post a Comment
To
MedHelp Health Answers
Recent Activity
Avatar_m_tn
Blank
ill13632 severe disease Comment
Apr 14
1317224_tn?1378708734
Blank
MaryLL I'm feeling good 16 months ... Comment
Apr 13
1317224_tn?1378708734
Blank
MaryLL uploaded new photos
Apr 13
Blank
BloodPressure Tracker
Monitor Your Blood Pressure
Start Tracking Now
Heart Disease Community Resources
RSS Expert Activity
242532_tn?1269553979
Blank
Emotional Eaters: How to Silence Yo...
Mar 26 by Roger Gould, M.D.Blank
1344197_tn?1392822771
Blank
Vaginal vs. Laparoscopic Hysterecto...
Feb 19 by J. Kyle Mathews, MD, DVMBlank
1684282_tn?1350782543
Blank
The Death by Heroin
Feb 03 by Julia M Aharonov, DOBlank
Top Heart Disease Answerers
976897_tn?1379171202
Blank
ed34
watford, United Kingdom
63984_tn?1385441539
Blank
Flycaster305
97303, OR
159619_tn?1318997813
Blank
erijon
Salt Lake City, UT
Avatar_f_tn
Blank
skydnsr
212161_tn?1391090750
Blank
heartfluttersflyawayplz
hoschton, GA
612551_tn?1247839157
Blank
Jerry_NJ
NJ