CAN TISSUE DOPPLER ASSESSMENT OF LONG AXIS FUNCTION BE USED AS A MARKER
OF LV CONTRACTILE RESERVE? B Haluska, L Short, P Cain, T Marwick. Princess Alexandra Hospital, University of Queensland, Brisbane, Qld. Exercise
echo (ExE) may be used to assess latent LV dysfunction in pts with valvular or
myocardial disease. However, measurement of contractile reserve (CR) is based
on comparison of rest and stress LV ejection fraction, which may be difficult
to measure post-exercise. Tissue Doppler measurement of myocardial Doppler
velocity (MDV) can be used to measure long axis function, which may be more
sensitive than radial contraction to minor disturbances of LV function. We
sought whether MDV could be used as a feasible clinical tool to quantify CR. Methods:
42 pts (15 women, age 52±20y) underwent a standard ExE for evaluation of
regurgitant valvular lesions (n=37) or as controls (n=6). Pulsed-wave MDV was
obtained in basal segts immediately after harmonic 2DE images at rest and
stress. Inducible ischemia was excluded by analysis of wall motion by an
experienced observer. CR was defined by an improvement of stress vs rest EF
(biplane Simpson) >4%. Exercise capacity (METS) was assessed from expired
gases. Results:
EF was 62±12% at rest and 62±18% at peak; CR was present in 20 pts (50%). Pts
with CR had peak EF of 75±7% (vs 51±17% in
CR-). CR could not be predicted by resting EF or volumes, but were
associated with differences in rest MDV and exercise parameters; DTI
rest ESV
peak DTI
peak Delta
DTI METS CR-
(n=22) 8±3 49±31 11±4 3±2 4.18 CR+
(n=20) 11±2 19±9 16±3 0.02 1.73 p 0.008 0.0002 0.0002 0.012 0.0004 Peak MDV correlated with peak EF (r=.60) and METS (0.62), but correlation of
% increments of MDV and EF was 0.36. In a multiple linear regression,
peak ESV, MDV, age and gender predicted CR (model R 0.93, p<.001). Conclusion:
In the absence of regional LV dysfunction, resting MDV correlates with CR, and
measurement of long axis function by MDV may be a marker of CR.
