Systolic and diastolic function affect dilated cardiomyopathy (DCM) outcomes. However, systolic-diastolic coupling, as a distinct characteristic, may itself affect function, but is poorly characterized. We hypothesized that echocardiographic left ventricular (LV) longitudinal systolic tissue velocities (S') correlate with diastolic longitudinal velocities (E'), that their relationship is associated with ventricular function and that this relationship is impaired in pediatric DCM. Methods & Results We analyzed data from the PHN VVV study; using linear regression and generalized additive modeling to assess relationships between S' and E' at the lateral and septal mitral annulus. We explored relationships between the S:D (systolic: diastolic) coupling ratio (S':E' relative to age), and ventricular function. Up to 4 echocardiograms from 130 DCM patients (mean age 9.3±6.1 years) and one echocardiogram from each of 591 healthy controls were analyzed. S' and E' were linearly related in controls (r=0.64, p<0.001) and DCM (r=0.83, p< 0.001). In DCM, the magnitude of association between S' and E' was reduced with progressive ventricular remodeling. The S:D ratio was more strongly associated with LV function in controls vs. DCM. The septal S:D ratio was higher (presumed worse) in DCM vs. controls (0.69±0.13 vs. 0.62±0.12, p=0.001). Higher septal S:D ratio was associated with worse LV dimensions (parameter estimate 0.0061, p=0.004), mass (parameter estimate 0.0074, p=0.002), ejection fraction (PE -0.0303, p=0.024) and inflow propagation (PE -0.3538, p<.001). Conclusions Systolic-diastolic coupling becomes weaker in DCM with LV remodeling and dysfunction. The S:D coupling ratio may be useful to assess coupling, warranting study in relation to patient outcomes.
- dilated cardiomyopathy
- Copyright © 2015, Journal of Applied Physiology