Instantaneous assessment of left ventricular midwall mechanics with tissue Doppler tracking technique.

BACKGROUND: Left ventricular (LV) systolic function is better characterized by midwall mechanics in patients with LV hypertrophy than by endocardial LV function, and the midwall mechanics is an independent predictor of prognosis. However, a complex calculation is currently required to assess it, and it is not routinely assessable in clinical practice. Tissue Doppler imaging enables tracking of a point within the LV wall though a cardiac cycle; we tested our hypothesis that the tissue Doppler tracking technique provides an instantaneous and reliable evaluation of midwall mechanics.

METHODS: LV M-mode echocardiogram was recorded in 18 subjects with conventional echocardiography and with tissue Doppler imaging. The midwall shortening was calculated from the data obtained with conventional echocardiography for the comparison with that measured with the tissue Doppler tracking technique. The tissue Doppler-determined midwall shortening correlated well with conventionally calculated value (r=.84, P<.0001), and their difference was small irrespective of absolute value of the midwall shortening.

CONCLUSIONS: The midwall mechanics can be instantaneously and accurately evaluated with the tissue Doppler tracking technique.