What does the first number in a typical BP reading (e.g., 110/70) represent?

What does the first number in a typical BP reading (e.g., 110/70) represent?

• A. Systolic pressure
• B. Diastolic pressure
• C. Pulse pressure
• D. Mean arterial pressure

Answer: (A)

During a blood pressure measurement the arterial pressure peaks with each heartbeat. The first number is the peak pressure in the arteries when the heart contracts and ejects blood into the aorta and systemic circulation, so it represents the systolic pressure. The second number, measured when the heart relaxes and the arteries refill, is the diastolic pressure. The difference between the two gives pulse pressure, and mean arterial pressure is a weighted average of the two values. So in a reading like 110/70, 110 mmHg is the systolic pressure.

During a blood pressure measurement the arterial pressure peaks with each heartbeat. The first number is the peak pressure in the arteries when the heart contracts and ejects blood into the aorta and systemic circulation, so it represents the systolic pressure. The second number, measured when the heart relaxes and the arteries refill, is the diastolic pressure. The difference between the two gives pulse pressure, and mean arterial pressure is a weighted average of the two values. So in a reading like 110/70, 110 mmHg is the systolic pressure.