Background: Patients with dilated cardiomyopathy (DCM) have abnormal LV diastolic properties. However, mitral regurgitation (MR), commonly encountered in these patients, affects the indirect Doppler assessment of LV filling based on transmittal blood flow velocities. We hypothesized that Color Kinesis (CK), which allows direct quantification of the magnitude and timing endocardial motion can identify diastolic dysfunction in patients with DCM and MR.Methods: We studied 24 patients with DCM (EF =<25%, end-diastolic dimension =<6.8 cm) and moderate to severe MR, and 24 age-matched normal subjects (NL). Diastolic CK images were analyzed to obtain peak filling rate normalized by heart rate (PFR, in units of end-diastolic area per beat) and mean filling time normalized by RR interval (MFT). Peak E and A velocities, and E/A ratios were obtained from Doppler tracings.Results: Doppler filling parameters measured in patients with DCM and MR were not significantly different from normal mean values: peak E = 79 +/- 12 vs 87 +/- 37 cm/s, and peak A = 67 +/- 17 vs 87 +/- 33 cm/s. In contrast, PFR and MFT obtained from CK images were significantly reduced in patients with DCM despite the presence of MR.Conclusions: Color Kinesis allowed identification of diastolic dysfunction in patients with DCM in whom Doppler assessment of diastolic function was confounded by MR.