Simple preimplant identification of optimum VV timing before cardiac resynchronization therapy: tissue Doppler imaging versus conventional 2D echocardiography.

AIMS: Optimum interventricular (VV) timing may potentially reduce the number of nonresponders to cardiac resynchronization therapy (CRT). We investigated whether optimum VV-timing interval could be determined before CRT implantation by means of tissue Doppler imaging (TDI) analysis and from visual assessment of conventional 2D echocardiography.

METHODS AND RESULTS: Thirty consecutive patients prospectively underwent 2D, 3D, and TDI echocardiographic evaluation before and 1 month after CRT. By using 3D echocardiography, LVEF was found to be increased from 23.8 +/- 6% to 35.7 +/- 9% 1 month after CRT (P < 0.001). NYHA class improved from 3.0 +/- 0.6 to 1.8 +/- 0.6 (P < 0.001). In 93% (77-99% with 95% confidence limits) of the patients optimum VV timing was correctly predicted based on preimplant TDI identification of the region with delayed myocardial contraction. A similar result could be obtained in 83% (65-94%) of the patients simply by visual assessment of conventional black and white 2D echocardiography (ns).

CONCLUSION: Preimplant TDI evaluation seems to be convenient for the determination of optimum VV timing. Further postimplant adjustment guided by TDI is hardly necessary unless patients do not experience clinical benefit. TDI may seem superior to visual assessment of dyssynchrony by means of conventional 2D echocardiography. However, this simple technique indicated optimum VV timing in the majority of cases in this study.