Master's student: Katrine Lindegaard
Master's project: Echocardiographic Assessment of Left Ventricular Systolic Function in Dogs
Assessment of left ventricle (LV) systolic function as part of the echocardiographic examination is pivotal for diagnostic, prognostic and clinical management purposes. Echocardiography is the modality of choice regardless of species. Many different modalities and indices have been investigated, but thorough knowledge of advantages and disadvantages is important to avoid erroneous conclusions. Fractional shortening (FS) is a commonly used index, where many breed-specific reference intervals exists. FS may cause incorrect assessment of systolic function in the diseased heart since it is a linear measurement that is highly load-dependent. Ejection fraction (EF) is another popular measurement based on volume differences during the cardiac cycle. Volume can be estimated by one-dimensional (1D), two-dimensional (2D) or three-dimensional (3D) measurements. 1D volume estimates should not be used since it results in incorrect estimates. 2D volume measurements by ”Simpson´s method of discs” are currently the measurement of choice since they perform well in both healthy and diseased LV. Although not yet used routinely in veterinary medicine, 3D and speckle tracking echocardiography (STE) derived strain and strain rate have shown promising results. The evidence of the advantages of these indices, compared to FS and EF, is steadily increasing, and in contrast to other modalities, STE can be used to evaluate both global and regional systolic function. Reference intervals are still lacking, but preliminary reference values have been reported. 3D and STE indices, therefore, have the potential to be part of the future assessment of LV systolic function in veterinary medicine.