What is the normal cardiac index?
Cardiac index (CI) is a haemodynamic parameter that relates the cardiac output (CO) from left ventricle in one minute to body surface area (BSA), thus relating heart performance to the size of the individual. The unit of measurement is litres per minute per square metre (L/min/m2).
Normal Hemodynamic Parameters
|Cardiac Output (CO)||HR x SV/1000||4.0 – 8.0 l/min|
|Cardiac Index (CI)||CO/BSA||2.5 – 4.0 l/min/m2|
|Stroke Volume (SV)||CO/HR x 1000||60 – 100 ml/beat|
|Stroke Volume Index (SVI)||CI/HR x 1000||33 – 47 ml/m2/beat|
- The cardiac output is simply the amount of blood pumped by the heart per minute. Necessarily, the cardiac output is the product of the heart rate, which is the number of beats per minute, and the stroke volume, which is amount pumped per beat. CO = HR X SV. The cardiac output is usually expressed in liters/minute.
- Cardiac index (CI) is a haemodynamic parameter that relates the cardiac output (CO) from left ventricle in one minute to body surface area (BSA), thus relating heart performance to the size of the individual. The unit of measurement is litres per minute per square metre (L/min/m2).
- Cardiac output is the amount of blood pumped out of the heart (ventricles) to the body per minute, and stroke volume is the amount of blood pumped out of your heart with each heartbeat. Stroke volume = 60-70 ml/heartbeat and cardiac output = 3-5 liters per minute.
Normal SVV values are less than 10-15% on controlled mechanical ventilation. The figures below demonstrate using SVV as a guide for volume resuscitation with a goal SVV of <13%. SVV increased to 19% with a stroke volume (SV) of 43 ml/beat, blood and saline were given to obtain a SVV of 6% and a SV of 58 ml/beat.
- Pulmonary capillary wedge pressure (PCWP) provides an indirect estimate of left atrial pressure (LAP). Although left ventricular pressure can be directly measured by placing a catheter within the left ventricle, it is not feasible to advance this catheter back into the left atrium.
- What does SVV stand for?
Rank Abbr. Meaning SVV Si Vales Valeo (Latin greeting: If You Are Well, I Am Well) SVV Software Verification and Validation SVV Stroke Volume Variation (medicine) SVV Subjective Visual Vertical
- Your heart can also increase its stroke volume by pumping more forcefully or increasing the amount of blood that fills the left ventricle before it pumps. Generally speaking, your heart beats both faster and stronger to increase cardiac output during exercise.
The amount of blood put out by the left ventricle of the heart in one contraction is called the stroke volume. The stroke volume and the heart rate determine the cardiac output. A normal adult has a cardiac output of 4.7 liters (5 quarts) of blood per minute.
- For adults 18 and older, a normal resting heart rate is between 60 and 100 beats per minute (bpm), depending on the person's physical condition and age. For children ages 6 to 15, the normal resting heart rate is between 70 and 100 bpm, according to the AHA.
- Ejection fraction is most commonly measured using echocardiography. This non-invasive technique provides good estimates of end-diastolic (EDV) and end-systolic volumes (ESV), and stroke volume (SV = EDV-ESV). Normally, EF is >60%. For example, if the SV is 75 ml and the EDV is 120 ml, then the EF is 63%.
- Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate. Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.
Updated: 4th December 2019