Page 1 of 1: List: CVS FORMULAS-add more formulas here as u remember

tanmay_mehta · Credits: 16361 My Scrapbook My Reading List 3 Books

i will start with very basic formulas

Each contraction of the heart results in an ejection of blood termed the stroke volume. The amount of blood pumped per contraction compared to the maximum left ventricular volume prior to contraction is the ejection fraction, which is a measure of the effectiveness of the heart as a pump.

The amount of blood pumped over a unit of time is the cardiac output. These can be divided to by the body surface area (BSA) which approximates blood volume and body size, thus allowing an index that can be used to compare individual patients.

stroke volume =
= ((end diastolic volume) - (end systolic volume))

stroke volume index =
= (stroke volume) / (body surface area)

ejection fraction =
= ((stroke volume) * (100%)) / (end diastolic volume)
= ((end diastolic volume) - (end systolic volume)) * (100%)) / (end diastolic volume)

cardiac output =
= (stroke volume) * (heart rate)

cardiac index =
= (stroke volume) * (heart rate) / (body surface area)

Interpretation:
The normal stroke volume index: 40-50 mL per contraction per square meter BSA.
The normal cardiac output: 3-7 liters per minute.
The normal cardiac index: 2.5 - 4.5 liters per min per square meter BSA.

add more formulas

tanmay_mehta · Credits: 16361 My Scrapbook My Reading List 3 Books

The systolic pressure is the maximum arterial pressure during the cardiac cycle, achieved during systole, whereas the diastolic pressure is the minimum, achieved during diastole. The pulse pressure is the difference between these two pressures. The mean arterial pressure is the area under the arterial pressure curve divided by the cardiac cycle duration (Berne); it can be reasonably approximated by calculations using systolic and diastolic pressures.

pulse pressure =
= (systolic systemic arterial pressure) - (diastolic systemic arterial pressure)

mean systemic arterial pressure =
= (diastolic systemic arterial pressure) + ((1/3) * (pulse pressure)) =
= (diastolic systemic arterial pressure) + ((1/3) * ((systolic systemic arterial pressure) - (diastolic systemic arterial pressure))) =
= ((systolic systemic arterial pressure) + (2 * (diastolic systemic arterial pressure))) / 3

Chemla's equation for mean systemic arterial (aortic) pressure =
= (diastolic systemic arterial pressure) + ((1/3) * (pulse pressure)) + 5

where:
Chemla et al studied the total area under the aortic blood pressure curve vs cardiac cycle, and found that the usual formula showed a bias with underestimation of about 5 mm Hg. I am not sure if measurement in a more peripheral artery (rather than the aorta) might affect the calculation.

rate pressure product =
= (systolic blood pressure in mm Hg) * (heart rate in beats per min) / 1000

Interpretation:
normal systolic arterial pressure: 100 - 140 mm Hg
normal diastolic arterial pressure: 60 - 90 mm Hg
normal pulse pressure: 30 - 50 mm Hg
normal mean arterial pressure: 70 - 100 mm Hg
normal heart rate: 60-100 beats per minute

tanmay_mehta · Credits: 16361 My Scrapbook My Reading List 3 Books

add more formulas plz..

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