QUANTITATIVE TISSUE DOPPLER-ECHOCARDIOGRAPHY - PHYSIOLOGICAL NONUNIFORMITY OF LEFT-VENTRICULAR TRANSMURAL MYOCARDIAL WALL-MOTION VELOCITIESAND GRADIENTS

Tissue Doppler echocardiography (TDE) is a new method by which transmu ral myocardial function can, be studied noninvasively. In, order to in vestigate physiology and reproducibility, 24 young, healthy volunteers were examined by M-mode TDE. Nonuniformity of transmural tissue layer velocities became apparent: Subendocardial and subepicardial velociti es of the anteroseptal myocardial wall (AW) were 3.5 +/- 0.7 and 1.3 /- 0.5 cm/sec (P < 0.0001, t-test), whereas in the posterolateral wall (PW) values of 3.6 +/- 0.6 and 1.2 +/- 0.4 cm/sec (P < 0.0001, t-test ), respectively, were revealed. The ratios, termed ''myocardial veloci ty gradients'' as a new indicator of left ventricular performance, wer e 3.1 +/- 1.0 and 3.4 +/- 1.1, respectively. AW and PW did not differ (N.S.). Tolerance borders did not overlap, and intraobserver variabili ty did not reach intersubject variability (P < 0.0001, F-ratio test). TDE provides new and more sophisticated insights into left ventricular performance. It seems to be accurate and reliable and therefore worth introducing into the clinical arena.