What Is A Beta Blocker?

— -- Question: What is a Beta blocker, how does it work, and when is it used to treat heart failure?

Answer: Beta blocker antagonizes another neurohormone in the body called norepinephrine, which is related to the hyperactivity of the sympathetic nervous system. And like the other neurohormones like aldosterone, like angiotensin II, norepinephrine also has a whole slew of deleterious effects on the cardiac myocyte, on the muscle function, on the vascular function.

And in patients who have coronary artery disease, or have myocardial infarction or congestive heart failure, it has been shown that if you were to give beta blockers to these patients, you'd reduce their mortality risk.

In patients who have heart attack reduce the risk of subsequent heart attacks and in patients with congestive heart failure, beta blocker therapy arguably is probably the most potent therapy that you can give to these patients which reduces all-cause mortality risk, risk for heart failure related mortality, certain cardiac death, improved their symptoms, their quality of life, and improve their ejection fraction.

So the benefits are many, but again we'd have to be careful that most of these data with beta blockers and heart failure are related to patients who have heart failure and systolic dysfunction or weakness of the heart muscle, and not necessarily those who have preserved ejection fraction, we do need more data on those patients.