Blood pressure is determined by cardiac output and systemic vascular resistance. Cardiac output is calculated by multiplying heart rate by stroke volume, and depends on how much blood the left ventricle pumps with each beat. Systemic vascular resistance refers to the resistance of blood vessels, which is influenced by vessel diameter, blood viscosity, and vessel rigidity. Together, cardiac output and systemic vascular resistance determine both systolic and diastolic blood pressure readings.

1. Blood Pressure (BP)
• Hemodynamic
• Pressure = Flow x Resistance
– Flow (movement of fluids)
– Resistance (vessels)

3. Terms/ Concepts
• Blood Pressure = F x R
– Flow (Cardiac Output {CO}) x
– Resistance (vessel diameter)
• CO = HR x SV
Heart Rate (HR) beats/min
Stroke Volume (SV)- blood ejected from L
ventricle; ml/beat

5. Blood Pressure (BP)
• Systolic Pressure (SBP)
• Diastolic Pressure (DBP)
• Pulse Pressure (PP)
– PP = S - D
• Mean Arterial Pressure (MAP)
– Perfusion pressure
MAP = CO x SVR (Systemic Vascular Resistance) or
MAP = SBP + 2(DBP)
3

7. BP from L ventricle through circ

8. BP
• Product of
– Cardiac Output (CO)
– Systemic Vascular Resistance (SVR)
• Viscosity of blood
• Vessel rigidity
• Vessel radius
• Maintained by adjusting CO for SVR
– if SVR high- body decreases CO