Abstract
Background: Diagnosis of ventricular dyssynchrony may play a role in patient selection for cardiac resynchronisation therapy. Various imaging techniques are available for diagnosis of dyssynchrony, including echocardiography and radionuclide imaging. Whether these techniques yield concordant results is not known. Methods: We studied 31 patients with left ventricular systolic dysfunction. Dyssynchrony was evaluated by echocardiography using interventricular mechanical delay (IVMD) and pulsed-wave tissue Doppler imaging (TDI). Dyssynchrony was also measured in the same patients using radionuclide angiography with nuclear phase analysis (NPA). Control subjects with normal systolic function were studied to determine cutoff values for each technique. Results: NPA was more likely to diagnose interventricular dyssynchrony than IVMD (68% vs 26% of patients, p = 0.001). Intraventricular dyssynchrony was more often diagnosed by NPA than TDI (84% vs 42%, p = 0.002). Agreement between echocardiography and NPA was poor in diagnosing inter- and intraventricular dyssynchrony (k <0.22 for all comparisons). Conclusion: Poor agreement between echocardiography and NPA in diagnosing dyssynchrony may be explained by the inherent differences between these techniques, which are therefore non-interchangeable. Recent data suggest that echocardiography has limited value in predicting response to CRT. As NPA evaluates dyssynchrony differently, it should be evaluated for this application.