Interpreting the bull's-eye plot in speckle tracking echocardiography

The bull’s-eye plot, much like the strain graph, is a visualized version of data collected from strain imaging echocardiography. It gives you information on how well segments of the left ventricle wall contract. The contractility is depicted both as colors and global longitudinal strain (GLS) values.

The evaluation of myocardial function can be tricky. This course will help you master an easy-to-follow process on how to acquire, optimize, and interpret left ventricular strain images. Using hands-on tips and tricks, you’ll cover global longitudinal strain (GLS) as well as important pearls and pitfalls as we go through several exciting real-life examples. Get ready to become an echo expert!

Now that you have learned how to optimize and acquire strain images, in this MedMastery lesson, I will teach you how to accurately interpret the bull's-eye plot, which provides a visual representation of myocardial contractility. Once the longitudinal 2D strain image acquisition and analysis is complete, and you click on process, the software automatically generates the bull's-eye plot, which displays all 17 left ventricle wall segments that were approved for tracking.

The orientation such as the septum, anterior, lateral, and inferior walls are relative to how the echocardiographic images show the left ventricle. Qualitatively, the color representation on the plot and color bar help to visualize and understand myocardial contractility at the segmental level, and provide an overview of the entire left ventricle. Red represents normal left ventricle wall contraction, as in shortening of the muscle fibres. Light red or pink indicates that the left ventricle wall is hypokinetic, meaning that the wall is not contracting normally or its function is reduced. Faded red or faded blue represents akinetic motion or in other words, the left ventricle wall is not contracting at all.

Lastly, if the segment is blue, then the wall is dyskinetic which means the wall segment is bulging out when it should be contracting. The software also provides a quantitative data, including the global longitudinal strain, or GLS values, which are indicated on the plot. Normal left ventricle wall motion is represented as less than minus 18%. But if the walls are hypokinetic, and not contracting, normally, the GLS value becomes less negative. If the left ventricle walls are akinetic, and do not contract at all, the GLS value would be zero or really close to zero. And if the left ventricle walls are dyskinetic, or bulging out, when it should be contracting, the GLS value is represented as a positive value. As you can see, the bull's-eye plot provides valuable information on overall left ventricle function. It is important to understand what the color represents, how the myocardium moves, and GLS values to properly interpret the strain results.