Tissue Doppler imaging and long axis left ventricular function: hypertrophic cardiomyopathy versus athlete's heart

Abstract

Background: The different diagnosis between hypertrophic cardiomyopathy and athlete's heart has important clinical implications. The assessment of long axis left ventricular function with tissue Doppler imaging in hypertrophic cardiomyopathy (showing systolic and diastolic dysfunction with heterogeneity and asynchrony), may be useful in the differentiation of these situations.

Aim: To study, with tissue Doppler imaging, long axis left ventricular function in a population of athletes (rowers) and to compare it with a population of non-obstructive hypertrophic cardiomyopathy patients.

Methods: In 24 patients with non-obstructive hypertrophic cardiomyopathy and in 20 competitive rowers with similar age, blood pressure and heart rate, we analyzed mitral annulus motion with pulsed tissue Doppler imaging in the 4 sides of the annulus (septal, lateral, inferior, anterior), in apical views. In each wave (systolic, rapid filling and atrial contraction) we measured velocities, time intervals and velocity-time integrals, and calculated heterogeneity and asynchrony indices. Data were compared between the groups, between the different sides in each group ("parallel analysis") and with conventional indices of global function.

Results: Hypertrophic cardiomyopathy patients showed: systolic function: lower velocities and integrals, shorter ejection time and shorter systolic time. These abnormalities occurred even in annular sites contiguous to walls without hypertrophy. DIASTOLIC FUNCTION: Much lower rapid filling velocities and integrals, lower atrial contraction velocities and integrals, lower e/a, longer isovolumic relaxation time and time to peak rapid filling wave. These abnormalities occurred even in annular sites adjacent to walls without hypertrophy. In the athletes group, the e/a ratio was never < 1, in any annular site. In hypertrophic cardiomyopathy patients this ratio was < 1 in 27% of the sites.

Conclusions: 1--Systolic and diastolic long axis left ventricular function is different in hypertrophic cardiomyopathy and in athletes, in all mitral annulus sides. 2--The presence of these abnormalities in annular sites contiguous to walls without hypertrophy suggests that this technique may be useful in the differential diagnosis between these groups, particularly in the "gray zone" of Maron.