Background: Left atrial (LA) strain is a valuable indicator of cardiac disease severity in humans and dogs. However, booster pump function cannot be assessed in many cats due to their high heart rates, limiting its clinical application. Hypothesis/
Objectives: To evaluate the feasibility of assessing booster pump function using high frame rate strain echocardiography in cats and its clinical utility. Animals: Forty-one client-owned cats with hypertrophic or restrictive cardiomyopathy phenotypes.
Methods: Cross-sectional study. Cats were classified as stage B or C according to the American College of Veterinary Internal Medicine consensus. Strain analysis images were obtained from the left apical four-chamber view, with the sector width minimized to enhance the frame rate. Diagnostic performance for detecting stage C was assessed using receiver operating characteristic (ROC) curves.
Results: Booster pump function was successfully evaluated in 35 of 41 cats with 88–429 frames per second. ROC analysis showed that reservoir strain (area under the curve [AUC] 1.00; cutoff 12.0%; sensitivity 100%; specificity 100%) and booster strain (AUC 1.00; cutoff 6.51%; sensitivity 100%; specificity 100%) outperformed conventional LA size indices, including LA diameter (AUC 0.995; cutoff 17.7 mm; sensitivity 100%; specificity 94.1%) and LA to aortic root ratio (AUC 0.985; cutoff 1.89; sensitivity 100%; specificity 92.3%), in detecting stage C. Conclusions and Clinical Importance: Booster pump function could be assessed in many cats using high frame rate strain echocardiography, demonstrating its value in identifying stage C. Further studies are needed to verify its clinical usefulness in predicting the risk of heart failure and thromboembolism.
