Stroke Volume Variation

• Obtain a PSLAX view and measure the LVOT.
• Obtain the apical 5 chamber view.
• In pulse wave doppler, place the cursor through the outflow tract with the marker just proximal to the aortic leaflets.
• Visualize the VTI waveform over 10 to 15 respirations.
• Decrease the sweep speed to visualize an increased amount of respiratory cycles.
• Measure the tip of the largest and smallest waveform.
• Make sure to measure respiratory variation and not irregular beats.

Interpretation

Calculate the percent change of the largest to smallest waveform

A Change of 12% or more shows potential responsiveness to fluid in patients with normal systolic cardiac function and normal sinus rhythm

FREE method:

• less than 10% volume responsiveness less likely
• 10-15% indeterminant
• more than 15% volume responsiveness more likely

Tips

The pulse wave cursor should not pass through the septum of the heart

If the velocities are very high and aliasing it may be impossible to assess SVV

SVV is an unreliable tool to access volume responsiveness in patients with systolic LV dysfunction, right heart failure and arrhythmias such as AFib.

Figure 1 - Stroke Volume Variation, A5C View

Figure 2 - Stroke Volume Variation Measurment

Figure 3 - Stroke Volume Variation < 10%

Figure 4 - Stroke Volume Variation > 15%

Beaubien-Souligny, William, et al. “Extracardiac signs of fluid overload in the critically ill cardiac patient: a focused evaluation using bedside ultrasound.” Canadian Journal of Cardiology 33.1 (2017): 88-100.