The Effects of Age and Heart Rate on Tricuspid Annular Motion Velocities in Healthy Nonsedated Cats

Background: Age and heart rate have effects on myocardial velocities as assessed by color tissue Doppler imaging (TDI) in people. A similar phenomenon has been identified when left ventricular velocities are assessed in cats. To date, the effects of age and heart rate on tricuspid annular velocities of cats have not been assessed. Objectives: This study was designed to determine the relationships between age and heart rate and tricuspid annular velocities in cats as assessed by 2-dimensional (2D) color TDI. Animals: Fifty healthy nonsedated cats with age range from 3 months to 19 years old were studied. Methods: Tricuspid annular velocities were obtained with 2D color TDI. Effects of age and heart rate on tricuspid annular velocities were evaluated by simple linear regression. The strength of the linear relationship was determined by using coefficient of determination (R2). Results: A significant weak negative relationship was found between age and peak early diastolic annular velocity (E'; R2= 0.135, P= .018). No significant relationships between age and right ventricular (RV) systolic TDI values were found. Diastolic and systolic TDI parameters were not affected by heart rate with the exception of deceleration rate of early diastolic motion (DR; R2= 0.100, P= .025). Conclusions and Clinical Importance: Age and heart rate have minimal effects on tricuspid annular velocities. The present study provides reference ranges for tricuspid annular velocities in healthy cats and information for assessing the clinical utility of color TDI for evaluation of RV function in cats.