Introduction
Echocardiography is widely used as a noninvasive cardiac imaging technique in the clinical setting for the evaluation of heart structure and functions. Doppler echocardiography is a method used to identify the direction and velocity of blood flow and therefore, it is an integral part of the cardiovascular echocardiographic examination, providing a precise hemodyanamic evaluation of the heart (1).
Blood and tissue velocities measured by Doppler are widely used tools for the evaluation of cardiac systolic and diastolic functions. Blood flow causes high frequency, low amplitude signals that are obtained using Pulse Wave (PW) Doppler. Tissue Doppler Imaging (TDI) is designed to characterise low velocity, high amplitude signals from myocardial motion, and are obtained by inverting the low pass filter used in traditional Doppler to a high pass filter (2,3). Tissue Doppler imaging examines the longitudinal component of myocardial contraction throughout the cardiac cycle.
The diastolic parameters may show difference in distinct patient subgroups. Age-related changes in diastolic indices have also been found to be gender specific. In the elderly population, diastolic function deteriorates more significantly in female gender than in male. Furthermore, although standart Doppler values have been established in current guidelines, these values may also be variable according to racial and ethnical factors. Therefore, it is important to be aware of the normal reference values of cardiac Doppler data in the clinical setting according to age, gender, race and body surface area (4).
Recently, we, for the first time in Turkey, have reported two-dimensional echocardiographic normal reference ranges for cardiac chamber quantification in a large cohort of Turkish individuals (5). Besides the chamber sizes, essential data regarding the relationship between these measurements and age, gender, body surface area and geographical region-dependent differences have been provided.
In this study, we aimed to determine echocardiographic reference values for PW Doppler and TDI velocities in a healthy Turkish population to obtain normal Doppler findings and patterns according to age and gender.