What are the normal values for stroke volume (SV) and cardiac output (CO)?

Normal Values for Stroke Volume and Cardiac Output

The normal resting stroke volume is 80-90 mL in a 70-kg adult, and the normal resting cardiac output is 4-6 L/min, with both values varying based on body size. 1

Stroke Volume (SV)

• Normal resting stroke volume: 80-90 mL in a 70-kg individual 1
• Stroke volume represents the amount of blood ejected from the heart with each contraction 1
• Values are body size-dependent and should be indexed to body surface area when comparing across different individuals 2
• During exercise, stroke volume can increase to approximately 100 mL in healthy subjects, though it typically plateaus at 50-60% of maximal oxygen uptake 1
• In heart failure patients, peak stroke volume may only reach 50-65 mL compared to 100 mL in healthy individuals 1

Cardiac Output (CO)

• Normal resting cardiac output: 4-6 L/min, depending on body size 1
• Cardiac output is calculated as the product of stroke volume and heart rate 1
• During maximal exercise, cardiac output can increase 4- to 6-fold above basal levels in healthy individuals 1
• Patients with heart failure may achieve only 50% of the maximal cardiac output attained by healthy individuals at peak exercise 1

Important Clinical Considerations

Body size normalization is critical when interpreting these values:

• Cardiac index (CI) and stroke volume index (SVI) should be calculated by dividing by body surface area 2
• Normal values differ significantly by sex, age, and ethnicity 2
• Women typically have lower absolute stroke volumes than men, though cardiac index may be similar 2

Measurement technique matters substantially:

• Values obtained by 2D echocardiography are significantly lower than those measured by Doppler or 3D methods 2
• These techniques are not interchangeable and should not be directly compared 2
• The imaging modality and method of analysis should always be specified when reporting values 3

Age-related changes:

• Stroke volume index decreases with aging across all measurement techniques 2
• Cardiac index declines with age when measured by 2D and 3D echocardiography 2

Physiological Context

The relationship between these parameters follows the Fick equation: Cardiac Output = Stroke Volume × Heart Rate 1. During exercise, increases in cardiac output are initially accomplished by increases in both stroke volume and heart rate, but at moderate to high intensity exercise, the increase is almost exclusively through heart rate augmentation as stroke volume plateaus 1.