effects of cardiac resynchronization therapy on mitral regurgitation in heart failure patients

background: cardiac resynchronization therapy (crt) has been introduced as a promising therapeutic choice in heart failure (hf) patients with ventricular dyssynchrony, shown with a wide qrs. in previous study, we showed a positive effect of crt on ejection fraction. this study aimed to evaluate the effect of crt on the severity of mitral regurgitation (mr) quantitatively using the volumetric doppler method in hf patients. materials and methods: in this prospective before-after survey, 22 hf patients with wide qrs (≥120 ms) and nyha class iii who were included. all patients were evaluated initially for qrs width, nyha class, mr volume, mr fraction and mitral valve area (mv area). biventricular pacing was done through cardiac-resynchronization device along with three pacing leads and same evaluations were done after crt. results: the mean (sd) qrs width and nyha class were significantly decreased after crt in hf patients (p 0.001). also mr volume (46.9±30.2 ml vs. 27.0±26.4 ml, p 0.001) and fraction (40.1±25.5% vs. 26.8±22.7%, p=0.002) were improved following crt. the decrease of mv area after crt was also significant (10.6±3.0 cm^2 vs. 8.6±2.6 cm^2, p 0.001). conclusion: as mr is associated with morbidity and mortality in hf patients and the standard surgical therapy may not be practical for a majority of them, this novel treatment may improve their disease condition significantly.