What is the typical exercise response when taking beta blockers?

What is the typical exercise response when taking beta blockers?

• A. Blunted heart rate and blood pressure responses, with reduced VO2max
• B. Increased VO2max
• C. No change in fatigue
• D. Increased maximal cardiac output

Answer: (B)

Beta blockers dampen the heart’s response to exercise by blocking beta-adrenergic receptors, which reduces both heart rate and myocardial contractility during activity. Because of this, heart rate at a given effort rises less, and the blood pressure increase is smaller. Maximal cardiac output is typically reduced due to the slower heart rate (and sometimes lower stroke volume). Since VO2max depends on how much oxygen the heart can deliver (VO2max ≈ cardiac output × (a-vO2) difference), a lower cardiac output generally leads to a reduced VO2max. So the common exercise response on beta blockers is a blunted heart rate and blood pressure response with a reduced VO2max.

Beta blockers dampen the heart’s response to exercise by blocking beta-adrenergic receptors, which reduces both heart rate and myocardial contractility during activity. Because of this, heart rate at a given effort rises less, and the blood pressure increase is smaller. Maximal cardiac output is typically reduced due to the slower heart rate (and sometimes lower stroke volume). Since VO2max depends on how much oxygen the heart can deliver (VO2max ≈ cardiac output × (a-vO2) difference), a lower cardiac output generally leads to a reduced VO2max. So the common exercise response on beta blockers is a blunted heart rate and blood pressure response with a reduced VO2max.