Tissue Doppler imaging; Cardiac resynchronization

Echocardiography is playing an increasing role in patient selection for cardiac resychronization therapy (CRT). The most frequently used techniques for evaluating inter- and intraventricular dyssynchrony are standard echocardiography and tissue Doppler imaging (TDI). Whether these techniques give concordant results is unknown. We studied 44 patients with a left ventricular ejection fraction of 0.35. Dyssyn-chrony was evaluated by standard echocardiography using the techniques described in the CARE-HF trial (interventricular mechanical delay and delayed motion of the posterior wall). Dyssynchrony was also measured by pulsed-wave TDI using delay to onset (Smo) as well as to peak (Smp) sustained systolic motion of the right ventricular free wall and of 4 basal segments of the left ventricle. A control group of 40 subjects with normal systolic function was studied for determining cutoff values. Agreement between standard echocardiography and TDI was poor for diagnosing inter- and intraventricular dyssyn-chrony (k, 0.33 for all comparisons). None of the patients had evidence of intraventricular dyssyn-chrony when evaluated for delayed posterior wall motion, whereas dyssynchrony was seen in 15/44 (34%, p 0.001) patients using left ventricular dispersion of Smo. 20 ms. Parameters using Smp were highly variable with poor reproducibility, making them unsuitable for evaluating dyssynchrony. In con-clusion, our study indicates that there is poor agreement between standard echocardiography and TDI for diagnosing dyssynchrony