Beta blockers

  I would like to know more information on how beta blockers can be used in the treatment of congestive heart failure.  I am currently a second year Physician Assistant student and there is alot of conflicting information on either the benefit or adverse effects of the drugs.  Thank you .
  Kerry

[CCF Cardio MD - MTR]

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Dear Kerry, thank you for your question.  Beta-blockers were long thought to be contraindicated in heart failure because of their negative inotropic properties - that is they depress the pumping function of the heart which is the underlying problem (at least in systolic heart failure).  Diastolic heart failure is another problem that we won't deal with here.  However, research in the last ten years has found that increased levels of neurohormones (catecholamines, norepinephrine, tumor necrosis factor, etc.) play a role in modulating heart failure.  Beta-blockers are known to block the actions of neurohormones which often act via the beta receptor.  Clinical trials have identified Coreg (carvedilol) as the most promising beta blocker to treat heart failure.  Coreg has alpha and beta blocking properties and may have an added effect on neurohormones since some act via alpha receptors as well as beta receptors.  Also, Coreg is thought to not have as great of a negative ionotropic effect on the left ventricle as other beta blockers. In practice, we commonly use Coreg for patients that don't respond to good doses of digoxin, diuretics, and ACE inhibitors and for patient who are persistently tachycardic on those medications (by slowing the heart rate, Coreg will exert a long-term protective effect on the heart to decrease the work of the heart.
Overall, your best source of information would be review articles or actual clinical trials in the last few years on this subject.  Try doing a medline search and focusing on cardiology journals like Circulation and the Journal of the American College of Cardiology for articles on beta blockers and heart failure.  I hope this information helps.