MAP = _______ x ________

• A. Cardiac Output x Systemic Vascular Resistance
• B. Heart Rate x Stroke Volume
• C. Stroke Volume x Heart Rate
• D. Cardiac Output / Systemic Vascular Resistance

Answer: (A)

The moment-to-moment arterial pressure in the systemic circulation is governed by how much blood the heart pumps per minute (cardiac output) and how much resistance the vessels provide (systemic vascular resistance). The standard relationship is MAP = CO × SVR. Since cardiac output itself equals heart rate times stroke volume, you can also think of MAP as MAP = (Heart Rate × Stroke Volume) × SVR.

That’s why the best match is Cardiac Output × Systemic Vascular Resistance. The other expressions don’t fit: Heart Rate × Stroke Volume gives the cardiac output, not the arterial pressure, and Cardiac Output ÷ Systemic Vascular Resistance would not reflect arterial pressure correctly.