Beta-blockers

Beta-blockers in heart failure

β-blockers decrease the compensatory mechanisms of increased sympathetic activity by blocking the β-receptors on the excitable cells in the myocardium and blood vessels. A blockade of these receptors results in decreased cardiac contractile activity, decreased heart rate and cardiac output, decreased blood pressure, and decreased peripheral circulation. All these effects reduce the oxygen demand of myocytes. They are therefore considered to inhibit the neurohormonal cascade that leads to progression of heart failure.

β-blockers such as propranolol, carvedilol, and metoprolol are used in the treatment of heart failure, in addition to ACE-inhibitors and diuretics.

1

β-blockers inhibit the formation of the impulses in the SA node by:

2

What is NOT true about digoxin toxicity

3

The mechanism of β-blocker action does NOT include