Objective: Tissue Doppler imaging (TDI) is used routinely to quantify left ventricular function and filling pressure. However, there remains a lack of percentile-based normative reference values for these clinically important parameters.
Methods: Four hundred and fifty-three healthy subjects aged 35-75 years were included for analysis from the London Life Sciences Prospective Population (LOLIPOP) study. Subjects were free of manifest cardiovascular disease, cardiovascular risk factors, and significant coronary artery disease as determined by electron-beam computed tomography. They underwent 2D and Doppler echocardiography for assessment of left heart structure and function. TDI was performed at the septal and lateral mitral annular sites enabling on-line derivation of myocardial systolic velocity (Sa), diastolic velocity (Ea), and the ratio of Ea to transmitral E-wave (E/Ea).
Results: Reference ranges (5th and 95th percentile values) for septal, lateral, and average mitral annular Sa velocity, Ea velocity, and E/Ea ratio were derived for the whole cohort and for each of the four age groups (35-44, 45-54, 55-64, 65-75). Increasing age was associated with a significant attenuation in myocardial velocity when averaged from both the septal and lateral mitral annulus, exerting a greater influence upon average Ea velocity (P < 0.001) compared with average Sa velocity (P = 0.04). Average E/Ea ratio increased significantly with advancing age (P < 0.001).
Conclusion: The reference ranges presented for the TDI parameters of Sa velocity, Ea velocity, and E/Ea ratio will help to standardize the assessment of LV function by tissue Doppler echocardiography.