Use of Indices Combining Diastolic and Systolic Tissue Doppler Variables to Evaluate Right Ventricular Function in Dogs With Pulmonary Stenosis

BACKGROUND: Indices combining diastolic and systolic tissue Doppler variables, the Ee's' index (E/[e' × s']) and e'a's' index (e'/[a' × s']), have aided detection of myocardial dysfunction and in prediction of poor outcomes in humans with cardiovascular diseases. Studies of Ee's' and e'a's' indices in dogs have not been performed. HYPOTHESIS/OBJECTIVES: Dogs with pulmonary stenosis (PS) have elevated right ventricular (RV) Ee's' and e'a's' indices compared to healthy dogs, which will decrease after pulmonary balloon valvuloplasty (BV) or stent implantation. ANIMALS: Thirty client-owned dogs (15 healthy, 15 with PS). METHODS: Cross-sectional study. All dogs had echocardiography performed, including the measurement of RV diastolic and systolic variables and calculation of the Ee's' and e'a's' indices. Dogs with PS had echocardiography performed prior to and after interventional procedures. RESULTS: The Ee's' index was lower (p = < 0.001) in healthy dogs (median 0.43, range 0.23-0.74) compared to dogs with PS pre-operatively (1.49, 0.28-3.79). The e'a's' index was lower (p = 0.039) in healthy dogs (mean 8.03 ± 3.28) compared to dogs with PS pre-operatively (11.39 ± 4.03). Compared to pre-operative values, the Ee's' index (1.01, 0.36-1.62) and e'a's' index (8.35 ± 3.29) decreased (p = 0.018, p = 0.001, respectively) after pulmonary intervention in dogs with PS. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with PS have RV myocardial dysfunction that can be measured with Ee's' and e'a's' indices, and these values can be used to monitor response to pulmonary intervention over time. These findings suggest that calculation of Ee's' and e'a's' indices might have clinical importance in long-term management of dogs with PS.