Endomyocardial radial strain rate imaging during dobutamine stress echocardiography for the evaluation of contractile reserve in patients with dilated cardiomyopathy

Purpose Myocardial contractile reserve is associated with clinical prognosis in patients with dilated cardiomyopathy (DCM). We assessed myocardial contractile reserve using tissue Doppler strain rate imaging with dobutamine stress echocardiography in DCM patients. Methods Simultaneous echocardiography and left ventricular (LV) catheterization during dobutamine stress were performed in 20 patients with DCM, and echocardiography was performed in 31 control subjects. Dobutamine was infused at a starting dose of 5 μg/kg/min for 5 minutes and then at 10 μg/kg/min. Peak endomyocardial radial strain (ɛ) and systolic strain rate (SR sys ) measured with echocardiography and the maximum first derivative of LV pressure (LV dP/dt max ) derived from catheterization were used as indices of contractility. Their percentage change from baseline to the dose of 10 μg/kg/min was calculated. Results The ɛ and SR sys were significantly smaller in DCM patients than in controls. The LV dP/dt max , ɛ, and SR sys were significantly higher at the dose of 10 μg/kg/min than at baseline. The percentage change in SR sys was significantly correlated with the percentage change in LV dP/dt max . Conclusions Strain rate imaging during dobutamine stress in DCM might prove noninvasively informative for the evaluation of myocardial contractile reserve and provide insight into LV systolic dysfunction.