Comparison effect of three chamber pacemaker in patients with systolic dysfunction, on sign and symptom when its programmed based on echo cardiography versus factory suggested

Cardiac resynchronization therapy is beneficial for a majority of patients with medically refractory heart failure due to severe LV systolic dysfunction and prolonged interventricular conduction to optimally programmed Atrioventricular delay during CRT can be also important to maximize the response in left ventricular function.several echocardiographic method have been reported to be useful for determination of the optimal AVD .In this trial 40 patient with left ventricular systolic dysfunction, will be randomized in a fixed AV delay(factory suggested)and AV delay determined by echocardiography(inclusion criteria:patient with systolic left ventricular dysfunction; Ejection fraction<35%; sinus rhythm;function class 3or4 with medical therapy; QRS duration>120ms ).patient will be evaluated by echocardiography and clinical status prior to initiation of CRT and 2 month post implant.we want to comparison function class of patient (primary out come measure)between two group of them.

Vice chancellor for research Tabriz university of medical sciences