Abstract 1843: Automated Function Imaging (AFI): A New Onboard and Clinically Applicable Method of LV Global Function Assessment by Speckle Tracking.
Background: Echocardiographic quantification of left ventricular (LV) function is still limited by a significant lack of accuracy and reproducibility. Speckle tracking technique is based on a pure 2D grayscale ultrasound acquisition allowing calculation of segmental strains. In order to become clinically relevant, the speckle tracking technique has been implemented onboard for a quick and automated evaluation of LV function called AFI.
Objective: To evaluate feasibility, calculation time, accuracy and reproducibility of AFI in determining LV function in comparison to reference echo and angiographic methods.
Methods: 40 patients scheduled for an X-ray angiography were previously echo scanned the same day using a Vivid 7 system. Image quality, global parameters of LV function (ejection fraction, aortic flow, +dP/dt) and segmental contraction were conventionally measured. Global longitudinal strain parameter (GS) was obtained by 2 observers from the apical 2,3 and 4 chamber views after placing 3 landmarks in each view. GS was then compared to EF from both echo and angiography, but also to other hemodynamic echo parameters.
Results: GS was obtained successfully in 90% of patients. Mean calculation time including correction of the endocardial detection was less than 60 seconds. GS was significantly lower in patients with EF below 50% (−18±3% vs −9±5%, p<0.01). A strong correlation was observed between EF and GS (Table 1⇓) with good reproducibility.
Conclusion: Global Strain onboard obtained by AFI is clinically applicable and of high relevance in echocardiography as demonstrated by its short acquisition time, its feasibility and its high level of accuracy.