Final answer:
Stroke volume (SV) is calculated using an echocardiogram to find the difference between end diastolic volume (EDV) and end systolic volume (ESV). Ejection fraction (EF) is the percentage of blood ejected from the left ventricle each contraction and is calculated by dividing SV by EDV, then multiplying by 100%. The normal range for EF is 55-70%, while the SV range is between 55-100 mL.
Step-by-step explanation:
How to Calculate Stroke Volume and Ejection Fraction
Stroke volume (SV) is the amount of blood pumped by the left ventricle of the heart in one contraction. SV is calculated by measuring the end diastolic volume (EDV) and the end systolic volume (ESV) using an echocardiogram, and the difference between these values gives the SV. The formula to calculate stroke volume is: SV = EDV - ESV. A normal stroke volume range for an adult rests between 55-100 mL.
Ejection fraction (EF) represents the percentage of blood ejected from the left ventricle with each contraction. To calculate ejection fraction, SV is divided by EDV, which is then often expressed as a percentage. The formula for this calculation is: EF = (SV / EDV) × 100%. Normal ejection fractions range from 55-70%, with the average being about 58%. The ejection fraction is a crucial measurement in diagnosing and monitoring patients with heart disease.
The concept of cardiac output (CO) is also closely related, representing the volume of blood pumped by the heart in one minute. The equation for cardiac output is: CO = HR (heart rate in beats per minute) × SV. Factors like exercise can affect CO by altering heart rate and SV.