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. Dyssynchrony 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 dyssynchrony (κ < 0.33 for all comparisons). None of the patients had evidence of intraventricular dyssynchrony 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 conclusion, our study indicates that there is poor agreement between standard echocardiography and TDI for diagnosing dyssynchrony.
Keywords: Dyssynchrony; Echocardiography; Tissue Doppler imaging; Cardiac resynchronization therapy
Journal Article. 3494 words. Illustrated.
Subjects: Cardiovascular Medicine
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