When the arms are exercised, which statement helps explain angina risk during upper-extremity activity?

When the arms are exercised, which statement helps explain angina risk during upper-extremity activity?

• A. Angina occurs at a lower heart rate than with leg exercise
• B. Heart rate and blood pressure rise more steeply for upper-extremity work
• C. Pulmonary ventilation increases less rapidly than with leg exercise
• D. Angina occurs at higher workloads than with leg exercise

Answer: (B)

The key idea is that upper-extremity exercise causes a larger increase in cardiac workload than leg exercise. This shows up as a steeper rise in heart rate and systolic blood pressure for the same amount of work, boosting the rate-pressure product (a proxy for myocardial oxygen demand). In people with narrowed coronary arteries, this higher demand can outstrip oxygen supply, leading to ischemia and angina during arm activity. So the statement that heart rate and blood pressure rise more steeply with upper-extremity work best explains the greater angina risk. The other ideas either misstate the relationship or point to factors less directly tied to the ischemic risk during arm exercise.

The key idea is that upper-extremity exercise causes a larger increase in cardiac workload than leg exercise. This shows up as a steeper rise in heart rate and systolic blood pressure for the same amount of work, boosting the rate-pressure product (a proxy for myocardial oxygen demand). In people with narrowed coronary arteries, this higher demand can outstrip oxygen supply, leading to ischemia and angina during arm activity. So the statement that heart rate and blood pressure rise more steeply with upper-extremity work best explains the greater angina risk. The other ideas either misstate the relationship or point to factors less directly tied to the ischemic risk during arm exercise.