Right ventricle Outflow Tract Acceleration Time: Correlation with Left Ventricular Diastolic Function

Background: There are no available data about the measurement of acceleration time at the right ventricle outflow tract (AcT) and its relevance in the analysis of the left ventricular diastolic function (LVDF). Objective: To correlate AcT with echocardiographic parameters of LVDF. Method: Eighty-seven patients (58.4±14.5 years; 52% women) submitted to transthoracic echocardiogram assessing spectral and tissue Doppler of the transmitral flow and mitral annulus, AcT, left atrial volume (LAV), and pulmonary artery systolic pressure (PASP). Patients with systolic dysfunction of the LV and grades II and III diastolic dysfunction (DD) were excluded. Main analyses were performed using the Spearman’s Correlation Coefficient (SCC) and Pearson’s Linear Correlation Coefficient (PLCC). Results: A negative correlation between AcT value and age (PLCC – 0.36; Student’s t-test; p <0.001) and a positive correlation between AcT and E/A ratio (SCC 0.38; p<0.001), between AcT and E/e’ ratio (SCC 0.26; p=0.01), between AcT and E wave of the mitral flow (PLCC 0.36; p= 0.001) were found. LAV and PASP did not correlate with AcT. In patients with a normal diastolic function, AcT was higher when compared with the AcT in patients with Grade I DD (0.150±0.029ms versus 0.127±0.023ms; p<0.001; Student’s t-test). The threshold suggested in this subgroup of patients was 0.135s. Conclusions: The present study correlated, unprecedentedly, AcT with echocardiographic parameters of the LV diastolic function. AcT values lower than 0.135s were associated with grade I diastolic dysfunction and higher than 0.135s values were associated with normal diastole.