A new simplified method to estimate global longitudinal strain in oncology patients

• Author / Creator

  Kholaif, Naji

• Background:
  Global longitudinal strain (GLS) is currently a widely applied method to evaluate early left ventricular dysfunction in the oncology population. Its ability to predict left ventricular dysfunction is valid even in patients with normal ejection fraction. A significant limitation is its dependency on image quality. Suboptimal acoustic windows and in plane displacement result in considerable inter- and intra-observer variability. To overcome this limitation we sought a simplified method to estimate global longitudinal strain using few user-defined tracking points of the left ventricle.
  Methods:
  In 106 consecutive oncology patients who underwent echocardiography to evaluate for possible cardiotoxic effects of cancer medications as per current guidelines, additional simple strain measurements were performed. Using a tool of the Philips Q-lab software called ‘user defined measurements’ areas in the mitral ring and apical pericardium are tracked that have prominent speckles and are less confounded by noise. The percentage shortening of the distance between the mitral ring and the apex was measured in each of the 4 walls of the 2- and 4-chamber views and the average was reported as global simple strain. These values were compared standard GLS measurements.
  Results:
  The mean age was 55.6 years. 84% of study population were females. The mean ejection fraction was 61.2 ± 8.5. Of the study population 80% had no wall motion abnormality. GLS values were higher than simple global strain values, -20.5 ± 2.6% and -12.3 ± 2.6%, P < 0.05. There was a strong linear correlation between GLS and simple global strain (r= 0.7) which was superior to the correlation of each method with ejection fraction (r=0.54 for GLS and r=0.38 for simple strain).
  The inter-observer variability for the simplified method was tested in 22 patients and in 20 for GLS. The mean absolute difference in the simple global method was 0.25±0.22% and 1.1±1.0% for GLS. The mean relative standard error was 2.4% for the simplified method and 5.6% in GLS. Bland-Altman analysis showed a small bias (0.11) with a narrow limits of agreement (1.96 x SD), -0.5 to 0.73%. The beat to beat variability was tested in 12 patients, the mean absolute difference was 0.43±0.32% and the mean relative standard error was 3.7%. There was a small bias (-0.18) with narrow limits of agreement (1.96 x SD) -1.2 to 0.85%.
  Conclusion:
  The simplified strain method using tracking areas at the apex and base of the heart showed good correlation with the standard speckle-tracking GLS method. This method is less time consuming, the tracking is easier to evaluate and is less affected by image quality. It has good inter-observer and beat to beat variability. This method could potentially supplement and in some cases replace GLS -particularly in patients with poor acoustic windows.

• Subjects / Keywords

  • oncology
  • global longitudinal strain
  • A new simplified method
  • strain

• Graduation date

  Fall 2019

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-n674-da23

• License

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