Longitudinal isovolumic displacement of the left ventricular myocardium assessed by tissue velocity echocardiography in healthy individuals.

Rapid myocardial isovolumic motions are reportedly involved in the left ventricular reshaping process and may contribute to total systolic myocardial shortening. In this study, the qualitative and quantitative analysis of longitudinal myocardial isovolumic displacement was performed in 49 healthy individuals (23 men and 26 women) in age groups 21 to 49 and 50 to 76 years using tissue velocity echocardiography. The obtained isovolumic contraction and relaxation displacement curves were biphasic and displayed a significant regional heterogeneity most probably reflecting active presystolic and postsystolic reshaping of left ventricular cavity. Besides some sex difference in younger individuals, there was an age-dependent lengthening of the isovolumic relaxation time and their motion components. Even if being of short duration, the longitudinal myocardial isovolumic displacement may accounted for as much as 14% of the total longitudinal myocardial shortening, a fact which should be taken into consideration when assessing left ventricular systolic function.