Background: Myocardial velocities can be measured with both pulsed-wave tissue Doppler (PWTD) and color tissue Doppler (CTD) echocardiography. We aimed to (A) to explore which of the two methods better approximates true tissue motion and (B) to examine the agreement and the reproducibility of the two methods in a routine clinical setting.
Methods: For Study A, the displacements of 63 basal myocardial segments from 13 patients were examined with M-mode and compared with the velocity-time integral of PWTD and CTD velocities. For Study B, the basal lateral segments from 58 patients were examined with PWTD and CTD, and the peak myocardial velocities during systole (Sm), early diastole (Em), and late diastole (Am) were measured.
Results: Study A: CTD-based measurements of displacement were 12% lower than M-mode measurements (95% CI: -18%; -6%). PWTD velocity-time integrals measured at the outer edge of the spectral band were 40% higher (33%; 46%) than M-mode measurements. Study B: PWTD measurements of myocardial velocity were systematically higher than CTD measurements: Sm 7.51 versus 5.54, difference 1.97 +/- 1.41 cm/sec; Em 8.74 versus 6.86, difference 1.88 +/- 1.70 cm/sec; Am 7.46 versus 5.17, difference 2.29 +/- 1.82 cm/sec; P < 0.001 for all. Intraobserver coefficient of variation for Sm, Em, and Am were 6%, 12%, and 12% for PWTD, 14%, 13%, and 20% for CTD.
Conclusions: CTD measures numerically smaller tissue velocities than PWTD, mostly due to an overestimation of true tissue motion by PWTD. The methods have good agreement and comparable reproducibility.