Assessment of left and right ventricular systolic and diastolic synchronicity in normal subjects by tissue Doppler echocardiography and the effects of age and heart rate.

OBJECTIVES: This study examined inter- and intraventricular synchronicity in systole and diastole by tissue Doppler imaging (TDI), and investigated if these parameters and the regional velocities were affected by age and heart rate.
METHODS: TDI was performed in 106 normal subjects (64.3 +/- 9.5 years, 60% male) using three apical views and a six-basal, six mid-segmental model. The regional parameters measured off line in both ventricles included peak isovolumic contraction velocity IVC(M), peak sustained systolic velocity (SM), peak early diastolic velocity (EM), peak late diastolic velocity (AM), and the E/AM ratio, as well as their time to these peak velocities: T(IVC), T(S), T(E), and T(A).
RESULTS: The systole and diastole within the left ventricle (LV) was highly synchronized without difference in T (IVC), TS, TE, and TA. However, the right ventricle (RV) was about 20 msec later than the LV for T(IVC) and TS. For regional velocities, IVC(M), S(M), E(M), and A(M) were significantly higher in basal than mid-segments (all P < 0.001). In the base of the LV, SM, and EM were the highest at the lateral segment and the lowest at the anterolateral segment. Age and heart rate did not affect systolic velocities or the timing of events. In diastole, age correlated negatively with EM(r =-0.36 to -0.48, P <or= 0.001)and E/AM ratio(r =-0.37 to -0.51, P <or= 0.01), while increasing heart rate affected AM (r = 0.17 to 0.43) positively and TE(r =-0.49 to -0.66, P < 0.001)and TA(r =-0.85 to -0.93, P < 0.001)negatively.
CONCLUSION: (1). Systolic and diastolic functions of the normal hearts are highly synchronized, though LV contraction slightly preceded that of RV. (2). Age and heart rate predominantly affect the diastolic, but not systolic, parameters that need to be taken into account.