Hemodynamics Flashcards
Stroke Volume*
amount of blood ejected from the heart with each contraction
• Value 60-100 cc/beat
• Stroke volume equals cardiac output in cc/min divided by heart rate: SV = CO/HR
If stroke volume decreases, what does HR do to maintain adequate CO? *
↓SV = ↑HR
Cardiac Output *
the amount of blood pumped from the heart per min
• Value: 4-8 liters/min
Cardiac Output =*
stroke volume x heart rate
Cardiac Index*
cardiac output per square meter of body surface area; more accurate indicator of cardiac output – bc take in height and weight
• Value: 2.5-4.0 liters/min/mm2
• Cardiac output/body surface area
Mean Arterial Pressure
average pressure in mm Hg exerted on the arterial walls
• 70-90 mmHg
• MAP = systolic pressure + (diastolic pressure x2)
3
Systemic Vascular Resistance
the amount of resistance present within the systemic circulation to impede blood flow from the ventricle
• Value: 900-1600 dynes/sec/cm-5
• SVR = (MAP – right atrial pressure (CVP) x 80
/CO
Preload
The volume/pressure within the ventricles at the end of diastole; left side preload looks at filling pressure of left ventricle and is reflected by pulmonary capillary wedge pressure.
pulmonary capillary wedge pressure normal *
4-12 mmHg
PCWP 18-20 mmHg:
onset of pulmonary congestion
PCWP 20-25 mmHg:
moderate congestion
PCWP 25-30 mmHg:
severe congestion
PCWP 30 mmHg or greater:
pulmonary edema
Afterload*
resistance met by ventricle with the ejection of blood flow. Left side afterload is reflected by systemic vascular resistance (SVR).
Normal SVR
(Systemic vascular resistance) 900-1600 dynes/sec/cm-5
