What is the pressure generated on the left side of the heart?

• A. 60 mmHg
• B. 100 mmHg
• C. 120 mmHg
• D. 80 mmHg

Answer: (B)

The left side of the heart must produce enough pressure to push blood through the systemic circulation, and the value that best represents this driving pressure over the cardiac cycle is the mean arterial pressure. In a healthy adult, the systolic pressure peaks around 120 mmHg as the ventricle contracts, while the diastolic pressure sits near 80 mmHg. The mean arterial pressure, which reflects the average pressure driving blood through the vessels, is about 100 mmHg. So, 100 mmHg is the best single number to characterize the pressure generated by the left heart for sustaining systemic perfusion. The other options correspond to the peak systolic value (around 120), the diastolic value (around 80), or a lower value (60) that doesn’t represent the overall driving pressure.