B-Blockers cause reduced LVF?

  I am on beta-blockers for frequent PACs with episodes of couplets.  They do not seem to be helping.  I had a recent stress-echo with only findings being Left ventricular function at the lower limits of normal and abnormal septal wall motion of "questionable" significance.
  1.  Could beta-blockers be reducing my Left ventricular function as it was not reduced on an echo I had prior to beta blockers?
  2.  Can you explain what might cause one to have abnormal septal motion?

[CCF CARDIO MD APS]

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Dear Julie,
1. Beta blockers do slow the heart down (i.e. decrease the rate) and also decrease the force of contraction.
NOW, I must tell you that patients on beta-blockers can have an overall "sluggishness" appearance on their echo, but most physicians recognize this as being just what it is--normal LV function in a patient on beta blockers.
2.There are a few causes of abnormal septal motion:
a. A bundle branch block (roadblock in the electrical pathway of the heart).
b. After open heart surgery, the septum will often move abnormally.
c. Increased pressure on the right side of the heart can cause a bowing of the septum to the left.
In a person like you with a NORMAL heart (left and right), the findings you speak of are almost always benign.  
Ask your doctor about your ecg (i.e. do you have a bundle branch block), about whether or not your "low normal LV function" appears to be that of someone on beta blockers, and lastly ask him/her what the follow up should be if they feel their has been a "deterioration" in your LV function.  Keep in mind that I think it is most likely that your echo findings are benign.
I hope this information is useful. Information provided in the heart forum is for
general purposes only.  Only your physician can provided specific diagnoses and therapies.
Feel free to write back with further questions. Good luck!
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