DOPPLER EVALUATION OF LEFT-VENTRICULAR DIASTOLIC INFLOW AND OUTFLOW WAVE-FORMS IN NORMAL SUBJECTS

The measurements of the left ventricular inflow parameters do not nece ssarily reflect the measurements of the respective outflow ones. The A wave transit time from the mitral valve to the Left ventricular outfl ow tract has been demonstrated to have a fair correlation with measure s of the Left ventricular Late diastolic stiffness. We pel formed this study, to obtain the normal patterns of the diastolic left ventricula r outflow as well as inflow waveforms and to evaluate the roles of agi ng and other physiological parameters in their evolution. The study po pulation consisted of 60 healthy subjects (aged 22-66 years). They wer e divided into three groups: group I (aged 20-34 years), group 2 (aged 35-49 years), and group 3 (aged 50-70 years). Pulse-wave Doppler echo cardiography was performed to get the patterns of diastolic Left ventr icular inflow and outflow waveforms. With aging, the peak velocity and velocity-time integral of the transmitted transmitral E wave decrease d, and those of the transmitted transmitral A wave increased with a pr ogressive decrease in their ratio of transmitted transmitral E to A wa ve. The diastolic left ventricular inflows followed a similar aging co urse. There was no obvious aging trend in the A wave transit time from the mitral valve to the left ventricular outflow tract. Multiple Line ar regression analyses selected age as the most important determinant in the differences in most Left ventricular inflow and outflow indices among normal subjects. Besides, heart rate had modest influences on s ome Doppler indices. This study confirms the age related changes in th e left ventricular inflow waveforms and further establishes the concep t that the diastolic left ventricular outflow waveforms are also signi ficantly influenced by age and heart rate. Hence, both factors should be taken into account in interpreting the diastolic Left ventricular o utflow as well as inflow indices.