الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Heart failure (HF) is a clinical syndrome resulting from structural and/or functional impairment of ventricular filling or ejection of blood. Presented by clinical symptoms and/or signs of reduced cardiac output and/or pulmonary or systemic congestion at rest or with stress associated with elevated natriuretic peptide levels.
Dilated cardiomyopathy (DCM) is the third most common cause of heart failure (HF) and is the most common cardiomyopathy. It is diagnosed by the presence of left ventricular dilatation and left ventricular systolic dysfunction in the absence of abnormal loading conditions (i.e. hypertension or valvular disease) or coronary artery disease sufficient to cause global systolic impairment.
Cardiac Resynchronization Therapy (CRT) is a huge advance in the treatment of heart failure with reduced ejection fraction HFrEF as it proves to correct electrical and mechanical dyssynchrony by coordinating contraction in both ventricles based on all large clinical trials concerned with CRT.
Despite the considerable percentage of patients who fail to respond to CRT, a good number of patients gain the benefits of such therapy, this raises the priority of proper selection of patients who have predictors to become CRT responders like HFrEF ≤ 35 %, sinus rhythm, LBBB, wide QRS ≥ 130 ms, non-ischemic cardiomyopathy and still symptomatic despite OMT.
Functional MR in DCM is a result of Mechanical dyssynchrony: LBBB, dyssynchrony in the contraction of ventricles. It independently predicts mortality in patients with Heart failure (DCM).
The pathophysiology of Functional MR in DCM is a result of 3 mechanisms: decreased closing forces due to ventricular dyssynchrony, increased tethering forces and dilated mitral valve annulus due to ventricular dilatation, displacement of papillary muscles, restricted leaflet closure, and distortion of the ventricular shape geographically leads to improper coaptation of mitral valve leaflets.
Cardiac Resynchronization therapy effect FMR in DCM through immediate benefits and delayed benefits; (months). Immediate CRT effect; by improving the three forms of mechanical dyssynchrony through global synchronization, local synchronization, and AV synchronization.
Delayed CRT effect on FMR through LV reverse Remodeling is defined as regression of LV dilatation and improvement of LV functions.
Twenty–five patients were included in our study between October 2018 to June 2021, who had DCM with advanced heart failure HFrEF ≤ 35 %, sinus rhythm, LBBB QRS ≥130 ms, and still symptomatic despite OMT with mitral regurge (at least moderate degree), CRT was implanted in the 25 patients and followed up clinically and by Echo to evaluate the effect of CRT on the degree of MR. Out of the 25 patients, 15 patients have an improvement in MR degree and this improvement in MR is observed during 1-week after CRT implantation and remains fixed for 10 weeks after the CRT implantation period.