[The impact of cardiac resynchronization therapy on left ventricular diastolic function evaluated by speckle tracking imaging in patients with dilated cardiomyopathy].

Objective: To investigate the effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) diastolic function measured by speckle tracking imaging (STI) in patients with dilated cardiomyopathy (DCM).

Methods: CRT was performed in 21 DCM patients [15 male, mean age: 61.2 ± 11.2 (49-82) years].LV synchronization, LV systolic function and LV diastolic function were evaluated with conventional echocardiography, tissue Doppler imaging and STI before and 6 months after CRT.NYHA heart function was also assessed. Clinic Response to CRT was defined as improvement of more than 1 NYHA class.Response to CRT in echocardiography was defined as ≥ 15% reduction in LV end systolic volume at 6 months post CRT.

Results: There were 16 responders and 5 non-responders at 6 months post CRT.In terms of diastolic function, conventional echocardiography derived deceleration time was both prolonged in non-responders and responders. At 6 months post CRT, STI derived LV isovolumetric diastolic strain rate [(0.19 ± 0.11) /s vs.(0.14 ± 0.09)/s, P < 0.001] was significantly increased while early diastolic mitral valve blood flow velocity/left ventricular isovolumetric diastolic strain rate (680 ± 600 vs.787 ± 690, P < 0.04) was significantly reduced in responder group while remained unchanged in non-responder group.Furthermore, left ventricular isovolumetric diastolic strain rate negatively correlated with plasma brain natriuretic peptide level (r = -0.68, P < 0.05).

Conclusion: In CRT responders of DCM patients, LV diastolic function is significantly improved and this change could be detected more effectively by STI derived LV diastolic function parameters.