QUANTITATIVE ASSESSMENT OF ALTERATIONS IN REGIONAL LEFT-VENTRICULAR CONTRACTILITY WITH COLOR-CODED TISSUE DOPPLER-ECHOCARDIOGRAPHY - COMPARISON WITH SONOMICROMETRY AND PRESSURE-VOLUME RELATIONS

Background Tissue Doppler imaging (TDI) is a novel method of color-cod ing myocardial velocity on-line. The objective of the present study wa s to evaluate endocardial velocity with TDI as a method of objectively quantifying alterations in regional contractility over a wide range i nduced by inotropic modulation. Methods and Results Myocardial length crystals were used to simultaneously assess regional left ventricular (LV) function, and high-fidelity pressure and conductance catheters we re used to assess global LV contractility by pressure-volume relations in nine open-chest dogs. Mid-LV M-mode and two-dimensional color TDI images were recorded during control and inotropic modulation stages wi th dobutamine and esmolol. Predicted significant increases in TDI indi ces occurred with dobutamine: peak systolic velocity of 4.41+/-1.07 to 6.67+/-1.07 cm/s, systolic time-velocity integral (TVI) of 0.43+/-0. 12 to 0.62+/-0.10 cm, and diastolic TVI of 0.49+/-0.11 to 0.71+/-0.17 cm. Opposing significant decreases occurred with esmolol: peak systo lic velocity of 4.46+/-0.94 to 2.31+/-0.81 cm/s, systolic TVI of 0.47 +/-0.12 to 0.19+/-0.11 cm, and diastolic TVI of 0.55+/-0.11 to 0.33+/ -0.11 cm (*all P<.001 versus control). Changes in TDI peak systolic v elocity were correlated with changes in fractional shortening (r = .88 ) andshortening velocity (r = .87) by sonomicrometry. Changes in TDI p eak velocity from multiple mid-LV sites also correlated significantly with maximal elastance (r = .85+/-.04) from pressure-volume relations. Conclusions TDI measures reflect directional and incremental alterati ons in regional and global LV contractility and have the potential to quantify regional LV function.