Which statement best describes how beta blockers help in angina?

Which statement best describes how beta blockers help in angina?

• A. They increase myocardial oxygen demand.
• B. They reduce cardiac work by lowering heart rate, contractility, and myocardial oxygen consumption.
• C. They dilate peripheral arteries to improve perfusion.
• D. They increase myocardial oxygen demand.

Answer: (B)

Beta blockers help in angina by lowering the heart’s workload, which reduces how much oxygen the heart needs. They block sympathetic signals to the heart, producing a slower heart rate (negative chronotropy) and weaker contractions (negative inotropy). With the heart beating more slowly and with less force, oxygen demand drops. Slower beating also means a longer diastolic period, allowing more time for coronary blood flow and better oxygen delivery to the heart muscle. They don’t primarily dilate peripheral arteries to improve perfusion, and they don’t increase oxygen demand, which is why the statement about reducing myocardial oxygen consumption best explains their benefit.

Beta blockers help in angina by lowering the heart’s workload, which reduces how much oxygen the heart needs. They block sympathetic signals to the heart, producing a slower heart rate (negative chronotropy) and weaker contractions (negative inotropy). With the heart beating more slowly and with less force, oxygen demand drops. Slower beating also means a longer diastolic period, allowing more time for coronary blood flow and better oxygen delivery to the heart muscle. They don’t primarily dilate peripheral arteries to improve perfusion, and they don’t increase oxygen demand, which is why the statement about reducing myocardial oxygen consumption best explains their benefit.